Evaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis

Evaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Evaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis Ismail Abdullateef Raji, Auwal Abubakar Usman, Abdulrahman Ahmad, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-117324/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Background: Nigeria and indeed, entire Africa has been certified free of Wild Polio Virus (WPV) in 2020. However, the continent is still at risk of importation of WPV, especially in states like Sokoto in Nigeria, which has an international border. Furthermore, due to low immunity in some communities in Sokoto, outbreaks of the circulating Vaccine Derived Polio Virus (cVDPV) occur. Therefore, this paper evaluates the Acute Flaccid Paralysis (AFP) surveillance indicators in Sokoto state, Nigeria. Methods: This retrospective study was an analysis of routinely collected AFP surveillance data between 2012 and 2019 by the Sokoto state surveillance network. We assessed the Sokoto state AFP surveillance system using the AFP surveillance performance indicators. We performed all analyses using Microsoft Excel 2019. Results: Cumulatively, 3001 Acute Flaccid Paralysis (AFP) cases were reported over the evaluation period, out of which 1692 (56.4%) were males, and 2478 (82.4%) were below five years. More than half, 1773 (59.1%) had a fever at the beginning of the disease, and 1911 (63.7%) had asymmetric paralysis. The non-polio AFP rate (9.1 to 23.5%) and stool adequacy rate (92.5 to 100%) indicate high sensitivity. The proportion of cases that had stool samples collected early, timely transported to the laboratory and arrived at the laboratory in optimal condition were all above the World Health Organization (WHO) minimum standard of 80%. There was inadequate profile documentation of some suspected cases. Conclusions: Sokoto State has exceeded the WHO minimum standards in most of the AFP surveillance indicators. The performance of the system is sufficient enough to detect any reintroduction of WPV into the state. However, there is a need for improvement in data quality. Health Economics & Outcomes Research Infectious Diseases Health Policy AFP Poliomyelitis Evaluation Surveillance Indicators Sokoto Nigeria Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Wild Polio Virus (WPV) is a highly contagious viral disease that leads to poliomyelitis which mainly affects children below five years [ 1 ]. It transmitted human to human, mainly via the orofaecal route [ 2 ]. Out of 200 cases of poliovirus infection, one would lead to irreversible floppiness a limb (usually the lower extremities). Among those paralyzed, up to 10% die as a result of the failure of the respiratory muscles [ 1 ]. Following the introduction of the Global Polio Eradication Initiative in 1988, the proportion of new cases of paralysis due to WPV infection has dropped to less than one per cent [ 1 , 3 ]. The polio searchlight of the world is now on Pakistan and Afghanistan, as Nigeria was recently declared free of poliomyelitis [ 4 ]. Eliminating the poliovirus in the remaining endemic countries would have led to the biggest-ever internationally-coordinated open wellbeing exertion in history [ 1 ]. Poliomyelitis is of public health importance because it is among the few diseases that can be eradicated with cheap and effective vaccines [ 1 ]. To eradicate polio, every child must receive the polio vaccine. The vaccination should include those living in remote and underserved areas and in conflict zones like Borno state in Nigeria (where the last case in Nigeria was reported in 2016) [ 1 ]. The presence of just a child with poliovirus puts children worldwide at risk of contracting the virus. The continuous endemicity of poliovirus in certain countries may result in as numerous as 200 thousand new WPV cases each year and if unchecked may affect every continent within ten years [ 5 ]. Worse of all, once poliovirus causes paralysis, there is no cure [ 5 ]. Acute Flaccid Paralysis (AFP) cases present with similar symptoms and signs with poliomyelitis; hence, AFP surveillance is used worldwide as an approach for monitoring and evaluating the achievements of polio eradication initiative [ 6 ]. Sensitive AFP surveillance is able to detect all cases of poliomyelitis for immediate public health action. In countries that have been certified polio-free, effective AFP surveillance is a strategy to continually evaluate the absence of transmission [ 7 , 8 ]. In countries that are not yet declared polio-free, surveillance plays a central role in the eradication process [ 9 ]. Therefore, high-quality AFP surveillance system is needed in proving and maintain the successful interruption of WPV [ 10 ]. Nigeria and indeed, entire Africa has been certified free of WPV [ 4 ]. However, the continent is still at risk of importation of WPV from Pakistan and Afghanistan, especially in states like Sokoto, which has international borders. Furthermore, the rare form of the poliovirus, the circulating Vaccine Derived Polio Virus (cVDPV) is affecting communities in Africa that are under-immunized, especially among hard to reach communities, migrant population, and those in conflict zones [ 9 ]. This is the case in Sokoto state where in the last one year, the state has recorded 6 cases of cvDPV2 from different sources – an indication of low population immunity and favourable factors for the transmission of cVPDVs [ 11 ]. Therefore, it is essential to continuously ensure that the AFP surveillance in Sokoto state is reliable enough to guide public health response towards the eradication of cVDPV in the context of the polio endgame strategic plan 2019 to 2023 [ 12 ]. Therefore, this study describes the findings from an eight-year AFP surveillance in Sokoto State and assesses the performance of the system with respect to the World Health Organization (WHO) surveillance indicators besides identifying the aspects that need improvement. Methods Study setting and design Sokoto state is located in Northwest Nigeria, covering about 27,825 km 2 [ 13 ]. It shares a border with the Niger Republic to the North – making it prone to cross border importation of poliovirus[ 14 ], Zamfara state to the south and east, and Kebbi state to the west and south. The state has 23 Local Government Areas (LGAs) out of which four are metropolitan. The projected population of Sokoto state for the year 2019 using a growth rate of 3.01% from the 2006 national census [13] was 5,475,895, with children under-five and under-15 years having a projected population of 114,069 and 268,1364 respectively. The state has a substantial nomadic population who are polio high-risk group [ 14 ]. Description Of The Afp Surveillance System In Sokoto State The mode of operation of the Sokoto state AFP surveillance system is similar to the other 35 states and the Federal Capital Territory, and it is part of the broader AFP surveillance system in Nigeria (Fig. 1 ). In the surveillance system, an AFP case is defined as "Any child under 15 years of age with the acute (sudden) onset of weakness or floppiness of one or more limbs or any person of any age with paralytic illness in whom a clinician suspects poliomyelitis" [ 15 ]. The primary purpose of the AFP surveillance system in Sokoto state is to detect and document the presence or absence of Wild Polio Virus in the state. The objectives of the AFP surveillance system in Sokoto state include: To provide data-driven evidence that guides the advancement of strategies that lead to polio eradication. To identify areas of cVDPV in Sokoto state. To investigate all detected AFP cases and demonstrate the non-transmission of WPV in Sokoto state. To assess the effect of Routine Immunization Activities (RIAs) and Supplementary Immunization Activities (SIAs) against polio. The flow of data in the AFP surveillance in Sokoto state begins with the notification of every case by community informants (such as traditional bone setters) or the health facility focal persons to their respective LGA Disease Surveillance and Notification Officers (DSNOs). The DSNOs are responsible for ensuring that adequate stool samples are collected from suspected cases. They are also responsible for ensuring that the samples get to the national polio laboratory in Ibadan, Oyo state in optimal temperature accompanied with correctly filled AFP Case Investigation Forms (CIFs). The LGA DSNO has an assistant DSNO, and he is also supported by an LGA facilitator who is on the WHO payroll. The LGA DSNO is responsible for giving regular feedback to the reporting facilities, focal persons and communities. The state epidemiologist and the state DSNO facilitate and oversee the activities of the LGA DSNO. The WHO cluster consultants assigned to different LGAs are responsible for verifying the suspected cases and conducting 60-day follow-up for cases that were not investigated within 14 days of onset of paralysis. The state epidemiologist gives feedback to the LGAs and reports to the Nigeria Center for Disease Control (NCDC), National Primary Health Care Development Agency (NPHCDA), Federal Ministry of Health (FMoH); and the state DSNO gives feedback to the LGAs on laboratory results (Fig. 1 ). The funding of AFP surveillance System in Sokoto State is by the federal government, Sokoto state government, and LGAs with robust technical and financial support by development partners notably, WHO and Centers for Disease Control and Prevention (CDC) / Africa Field Epidemiology Network (AFENET). WHO sponsors the active case finding visits by DSNOs to AFP reporting sites. Additionally, the organization supports the DSNOs with transportation allowances to attend the monthly surveillance meetings at the states' capital. CDC/AFENET provides technical and human resource support to all the LGAs to complement Government resources. Study Design We conducted a retrospective descriptive analyses of AFP surveillance data in Sokoto state from January 2012 to December 2019. We included AFP cases reported in all the LGAs within the period in this study. We evaluated the AFP performance using the WHO indicators for assessing the AFP surveillance system [ 16 ]. Data Collection And Analysis We sieved out information on age, gender, Oral Polio vaccine (OPV) doses, fever at the onset, asymmetry of paralysis, the progression of paralysis in 3 days and classification as true AFP. All analyses were done using Microsoft Excel version 2019. We conducted descriptive analyses and generated core performance indicators and other indicators recommended by the WHO for assessing the AFP surveillance system [ 16 ]. Results In total, 3001 AFP cases were identified and reported by the AFP surveillance system in Sokoto between January 2012 and December 2019. Out of these, more than half, 1692 (56.4) were males, and more than three-quarters, 2478 (82.4%) were less than five years old. Almost all, 2959 (98.6%) had taken three or more OPV doses. More than half, 1773 (59.1%) had a fever at the onset of the disease, and many 1911 (63.7%) had asymmetric paralysis. More than one-third, 1178 (39.3) of cases had a progression of paralysis in 3 days (Table 1 ). Illela LGA had the highest proportion of cases cases, 251 (8.4%); while Tureta LGA had the least number of cases, 72 (2.4%) over the evaluation period (Fig. 2 ). Cumulatively, the Sokoto State annualized non-polio AFP detection rate was 16.7 AFP cases per 100,0000 population below 15 years, indicating a sensitive AFP surveillance. Over the evaluation period, the annualized non-polio AFP rate was consistently above the minimum target of ≥ 2/100,000 in the state. (Table 2 ). Disaggregating the state cumulative non-polio AFP rate by LGAs showed that all the LGAs consistently surpassed the WHO minimum of 2 AFP cases per 100, 000 population of children below 15 years during the 8 years evaluation period (Fig. 3 ). There was a consistent increase in the proportion of AFP cases with adequate stools from 92.5% in 2012 to 100% in 2016 and a drop to 96% in 2018 and 2019. Over the evaluation period, the stool adequacy performance was above the minimum target of 80% for the state (Table 2 ). Disaggregated by LGAs, all the LGAs met the minimum standard except, Kware, 67% in 2012; Yabo, 71% in 2018 and Tangaza, 75% in 2019 (Fig. 4 ). All stool samples arrived at the laboratory within 72 hours of being sent during the evaluation period (Table 2 ). The laboratory performance indicator, Non-polio Enterovirus (NPENT) rate, was above the minimum level required over the 8-year evaluation period. (Table 2 ). Table 1 Profile of the AFP cases reported in Sokoto state, Nigeria, 2012–2019 Profile Number of AFP cases Percent (n = 3001) Age group (years) ≤ 5 2478 82.5 6–10 383 12.8 11–15 17 0.6 > 15 91 3.0 Unknown age status 32 1.1 Gender Male ‎ 1692 56.4 Female 1309 43.6 OPV doses < 3 42 1.4 ≥3 2959 98.6 Fever at onset Yes 1773 59.1 No 78 2.6 Missing 1150 38.3 Asymmetry Yes 1911 63.7 No 415 18.3 Missing 541 18.0 Progression in 3 days Yes 1178 39.3 No 52 1.7 Missing 1771 59.0 Classified as true AFP Yes 1187 39.6 No 31 1.0 Missing 1783 59.4 Table 2 AFP performance indicators for Sokoto State, Nigeria, 2012–2019 Performance indicator Target State performance 2012 2013 2014 2015 2016 2017 2018 2019 Annualized non-polio AFP rate /100,000 < 15 years population ≥ 3 13.5 15 20.1 23.5 19.1 21.7 11.8 9.1 Proportion of AFP cases with two adequate stool specimens ≥ 80% 92.5 97 99.3 100 100 99.7 96.7 96.1 Timeliness of monthly reporting ≥ 80% 100 100 89 100 96 100 100 96 completeness of monthly reporting ≥ 90% 100 100 99 100 97 100 100 97 Proportion of AFP cases investigated within 48 hours of notification ≥ 80% 98.3 100 100 99.4 100 100 100 100 Reported AFP cases with follow-up exam at least 60 days after paralysis onset. ≥ 80% 80.8 100 100 100 100 100 100 100 The proportion of specimens that arrived at a WHO accredited laboratory < 3 days of being sent ≥ 80% 100 100 100 100 100 100 100 100 Proportion of stool specimens arriving at the laboratory in good condition ≥ 80% 99.3 99.5 100 99.8 99 99 100 100 Proportion of stool specimens from which non-polio enterovirus was isolated NPENT ≥ 10% 14.9 11.1 11.4 9.5 14 13 14 13 AFP surveillance index ≥ 1.6 12.5 14.6 20.0 23.5 19.1 21.6 11.4 8.7 Discussion This study involved a state-wide analysis of AFP surveillance data in Sokoto State and reports the findings of the evaluation of APF surveillance indicators from 2012–2019. Over the evaluation period, we found that children below five years were most affected, with over 80% of the cases. This finding corroborates what has been stated by WHO that under-five children are most affected [ 17 ]. The finding indicates that the AFP surveillance system is identifying the primary age group affected. The finding in this study is comparable to what was reported in the evaluation of surveillance system in Ibadan (74.3%)[ 18 ] and in Akwa Ibom (82.5%)[ 19 ] states in Nigeria and Ghana(76.3%) [ 20 ]. However, a surveillance system evaluation in Zambia showed that 63% of cases were in the age group 10–15 years [ 21 ]; although a significant proportion of the cases did not have their age documented in the study which could have been responsible for their finding. More than half (56.7%) of the AFP cases observed in this evaluation were males. This finding is similar to what was reported in Ghana (55.8%)[ 20 ] and South Africa (54.3%) [ 8 ]. Almost all the AFP cases have had at least three doses of OPV through RIAs and SIAs activities. This is encouraging because it is an indication that Sokoto State is implementing the global polio eradication strategies. A similar finding was reported in the surveillance system evaluation in Ghana [ 20 ]. Worthy of note in the surveillance data was that some characteristics of the AFP cases were not documented. For example, 38.3% of the cases did not have documentation presence of fever at the onset of paralysis, and 59% did not have documentation on the progression of paralysis. This information is essential in determining whether a case is a "hot" case or not [ 15 , 22 ]. Therefore, this poor quality of data can affect the performance of the surveillance system. Maintaining a sensitive surveillance system that can detect WPV is critical in the eradication of poliomyelitis by enabling early response to importations and in certifying the complete interruption of transmission [ 12 ]. A well-performing AFP surveillance system should be able to pick a minimum of two AFP cases per 100,00 children younger than 15 years [ 23 ]. This is used as a proxy of the sensitivity of AFP surveillance system. This indicator measures the capacity of the surveillance system to detect AFP cases due to other causes than polio [ 15 ]. In this study, we found the AFP surveillance system in Sokoto to be sensitive. The minimum standard for non-polio AFP rate was surpassed throughout the period under review. It is crucial to monitor LGA performance because, state-level indicators may mask wide variation in LGA performance,[ 15 ] therefore, we disaggregated the data by LGA, and we found that all LGAs performed above the minimum standard. This finding is encouraging as Nigeria is no more an endemic country for polio transmission [ 4 ]; therefore, any reintroduction can be picked by the sensitive AFP surveillance system. This finding is especially important because Sokoto State has an international border. A similar finding was reported in Zambia, where the AFP detection rate was consistently above the national target for over five years of surveillance evaluation [ 21 ]. The finding our study is contrary to what was reported in a surveillance evaluation in Zimbabwe, where it was found not to be sensitive [ 24 ]. In South Africa, an increasing trend in the sensitivity of the AFP surveillance system was observed over five years – between 2005 and 2009; however, the target was only met in 2008 [ 8 ]. A stool specimen is adequate if collected 24–48 hours apart and within two weeks of the onset of paralysis and arriving at the laboratory in good condition [ 23 ]. The results from this surveillance evaluation showed that the proportion of stool samples adequately collected throughout the evaluation period was consistently above the minimum standard of 80%. After disaggregating, all LGAs performed well, except 3 LGAs (Kware in 2012, Yabo in 2018 and Tangaza in 2019). This finding could be an indication that the community and parents are aware of the AFP surveillance system, leading to early detection and reporting. The finding could also be an indication that there are minimal causes of delays such as lack of involvement of health workers or inadequate logistics such as stock-out of kit sand transport. The non-polio AFP rate and the stool adequacy rate are used as the standard for assessing the quality of AFP surveillance [ 22 ]. These two indicators can be combined into a single indicator of AFP surveillance quality, the surveillance index, which can be used to compare progress over time and or geographic differences [ 15 , 22 ]. In this surveillance evaluation, the surveillance index for the state was greater than 2.5, indicating a robust AFP surveillance on average [ 15 ]. Using this index in maps helps in identifying areas of risk. Fortunately, in Sokoto State, no area of risk was identified using this index. The success in the surveillance index could be due to the regular capacity building and financial support provided by the WHO to the LGA DSNOs. In addition to finding AFP cases, timeliness, and the quality of investigation of suspected cases are also vital in achieving the objectives of an AFP surveillance system. Stool samples were collected from almost all the suspected cases within 48 hours of notification. This could be attributed to proper training and supervision from WHO cluster consultants in the various LGAs in the state. Laboratory investigation is fundamental to the confirmation of WPV; therefore, the integrity of the faecal samples arriving the laboratory should be good enough for laboratory confirmation of the presence or absence of the virus with a reasonable level of certainty. No WPV was isolated in Sokoto State during the evaluation period; therefore, with the high stool adequacy rate, any form of poliovirus transmission will be most likely picked by the AFP surveillance in Sokoto state. The finding in this study defers from what was reported in the evaluation done in North Korea, where stool adequacy was consistently lower than the WHO recommended standard of 80% [ 25 ]. To maximize the opportunity to isolate the poliovirus, with the highest probability occurring within the first 14 days, some indicators of AFP surveillance assess the timeliness of certain surveillance activities [ 22 ]. A minimum of 80% of faecal samples should reach the laboratory within three days of sample collection. [ 23 ]. The result from this evaluation revealed that in Sokoto State, all the stool samples were received in the laboratory within three days during the evaluation period. This positive finding could be a result of the stipend given to any surveillance officers who transport the samples to the laboratory. A contrary finding was reported in South Africa were the WHO minimum target was not met with regards to the timeliness of transportation of samples to the laboratory [ 8 ]. The finding could be because, in South Africa, courier services were used, which could experience some delays; however, in Nigeria, Sokoto State inclusive, the LGA DSNOs are responsible for the immediate transportation of the sample to the laboratory. Very pivotal in the detection of poliovirus is the arrival of the stool samples in the laboratory within three days and samples being in good condition. These indicators also assess the timeliness of surveillance activities [ 22 ]. In this evaluation, at least 99 per cent of samples reached the designated laboratory in perfect condition, and all samples arrived at the laboratory within three days. This finding gives a high degree of confidence that whatever findings in the laboratory reflect the actual situation. This positive finding could be attributed to the frequent sponsored training on polio surveillance activities by WHO in the state, close monitoring of surveillance activities by cluster consultants and provision of stipends for surveillance officers. The AFP surveillance system met the target for timeliness of monthly reporting over the evaluation period. This finding is important because this allows the state to take all necessary early actions to ensure polio certification. The NPENT rate to assesses how the AFP surveillance system can maintain the reverse cold chain. It also to assesses the performance of the laboratories in the routine isolation of enteroviruses [ 15 ]. Sokoto state has performed well in this indicator over the evaluation period by exceeding the minimum value of 10%. This finding is important, especially in the post-polio era in Sokoto state, which still reports cVDPVs. It has been established that cVDPVs have the potential to combine and recombine with other enteroviruses, which can give rise to new strains of pathogenic [ 26 ]. Therefore, adequate NPENT surveillance will help detect and control any outbreak. Similar NPENT rates were recorded in the neighbouring Kebbi state between 2010 and 2015 [ 27 ]. An area of deficiency observed in this secondary data analysis is that the surveillance data obtained had no information on the timeliness of specimen processing. So we could not assess if stool sample results were sent back within 28 days of receipt of samples in the laboratory. It is essential to document this information as this will allow for assessment of the feedback channel. Overall, the AFP surveillance indicators are meeting-up with the minimum targets. However, this should not create a state of complacency as it was observed in Jigawa state in 2011 where all the minimum standard for certification were surpassed, but following analyses of environmental samples, WPV and cVDPV were detected, indicating that certain chains of transmission had been missed [ 22 ]. Therefore, surpassing most of the surveillance indicator targets should not allow lowering of surveillance guards. Conclusion The AFP Surveillance system in Sokoto State has performed well over the past eight years by exceeding the minimum WHO targets both at the state and LGA levels. The system is sensitive enough to detect any importation of new cases into the polio-free Sokoto. However, there is inadequate documentation of laboratory results and some profile information on the suspected cases. We recommend that the state ministry of health should ensure that data managers document whether laboratory results return within 28 days of receiving the samples in the laboratory. Abbreviations AFENET Africa Field Epidemiology Network AFP Acute Flaccid Paralysis CDC Centres for Disease Control and Prevention CIFs Case Investigation Forms cVDPV circulating Vaccine Derived Polio Virus DSNOs Disease Surveillance and Notification Officers FMoH Federal Ministry of Health LGAs Local Government Areas NCDC Nigeria Center for Disease Control NPENT Non-polio Enterovirus NPHCDA National Primary Health Care Development Agency OPV Oral Polio vaccine RIAs Immunization Activities SIAs Supplementary Immunization Activities WPV Wild Polio Virus Declarations Ethics approval and consent to participate : We sought ethical approval from Sokoto State Ministry of Health Research Ethics Committee before the commencement of the study. We protected the confidentiality of patients by using special codes. We expunged all personal identifying information from the data used. Data security was maintained using a password-protected computer. Consent for publication: Not applicable Availability of data and materials: The datasets generated analyzed during the current study are not publicly available because it is the property of Sokoto state Ministry of Health; however, the data but are available from the corresponding author on reasonable request. Competing interests Dr Chukwuma David Umeokonkwo , one of the authors of this manuscript is a member of the BMC Public Health editorial board member. Funding The authors of this study funded this study. Authors' contributions IAR participated in conceptualization, analyses, writing original draft, and review and editing. AAU was involved in conceptualization, analyses and interpretation of data, review and editing Abdulrahman participated in data acquisition, analyses and interpretation of data. BBL contributed to conceptualization, analyses and interpretation of data, review and editing. CDU was involved in methodology, review and editing. AAO contributed to methodology, review and editing. SG was involved in conceptualization, methodology and review and editing. MB supervised the manuscript writing, review & editing. All authors read and approved the final manuscript. Acknowledgements We are grateful to the World Health Organization, Sokoto for their contribution to data gathering in the state. The Nigerian Field Epidemiology and Training program for their technical guidance and manuscript writing workshop. Authors' information 1 Nigerian Field Epidemiology and Laboratory Training Program, Abuja, Nigeria. 2 Department of Community Medicine, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria 3 Department of Public Health, Ministry of Health, Sokoto 4 National Stop Transmission of Polio, Nigeria. 5 Department of Community Medicine, Ahmadu Bello University, Zaria, Nigeria. 6 Department of Community Medicine, Alex Ekwueme Federal University Teaching Hospital, Ebonyi, Nigeria. References WHO. 10 Facts on Polio Eradication. 2016. http://www.who.int/features/factfiles/polio/facts/en/index.html . Accessed 3 November 2019. CDC. Manual for the Surveillance of Vaccine-Preventable Diseases. Centers for Disease Control and Prevention, Atlanta, GA. CDC. Updates on Cdc's Polio Eradication Efforts. 2016. http://www.cdc.gov/polio/updates/ . 2019. WHO. Global Polio Eradication Initiative Applauds Who African Region for Wild Polio-Free Certification. 2020. https://www.who.int/news-room/detail/25-08-2020-global-polio-eradication-initiative-applauds-who-african-region-for-wild-polio-free-certification . Accessed 26th August 2020 2020. WHO. Poliomyelitis -Fact Sheets 2019. http://www.who.int/mediacentre/factsheets/fs114/en/ . Accessed 2nd January 2020. Tangermann RH, Lamoureux C, Tallis G, Goel A. The Critical Role of Acute Flaccid Paralysis Surveillance in the Global Polio Eradication Initiative. International Health. 2017;9(3):156–63. Global Polio Eradication Initiatitve. Surveillance 2010. http-//www.polioeradication.org/AboutUs/Strategy/Surveillance.aspx . Accessed Sep 26th 2016. Khuzwayo LS, Kuonza LR, Ngcobo NJ. Evaluating the Acute Flaccid Paralysis Surveillance System in South Africa, 2005-2009-an Analysis of Secondary Data. Pan Afr Med J. 2013; 14(1). WHO. Polio. 2020. https://www.afro.who.int/health-topics/polio . Accessed 14th August 2020. HPSC. Acute Flaccid Paralysis Surveillance: What Is It and Why Are We Doing It?: Health Protection Surveillance Centre. 2013. Global Polio Eradication Initiatitve. Gpei Strategy for Control of Cvdpv2 2020. http://polioeradication.org/wp-content/uploads/2020/07/cVDPV2-nOPV2-fact-sheet-July-2020.pdf . Accessed 3 September 2020. WHO, GPEI. Polio Endgame Strategy 2019–2023: Eradication, Integration, Certification and Containment. Geneva: World Health Organization; 2019. National Bureau Of Statistics. Annual Abstract of Statistics: Federal Republic of Nigeria. 2011. Bawa S, Afolabi M, Abdelrahim K, Abba G, Ningi A, Tafida SY, Tegegne SG, Warigon C, Nomhwange T, Umar SA, Aregay A, Fanti A, Ahmed B, Nsubuga P, Adamu U, Braka F, Wondimagegnehu A, Shuaib F. Transboundary Nomadic Population Movement: A Potential for Import-Export of Poliovirus. BMC Public Health. 2018;18(Suppl 4):1316–16. National Primary Health Care Develoement Agency and Partners. Gudielines for Poliovirus Surveillance Nigeria. June 2019 ed. WHO. Who Recommended Standards for Surveillance of Selected Vaccine-Preventable Diseases. Geneva: Department of Vaccines and Biologicals, Health Technology and Pharmaceuticals, World Health Organization; 2003. WHO. Poliomyelitis 2019. https://www.who.int/news-room/fact-sheets/detail/poliomyelitis . Accessed 17th June 2020. Hamzat T-hK, Omotade TT. Acute Flaccid Paralysis: A Five–Year Review of Cases Managed by Physiotherapy at the University College Hospital, Ibadan. Afr J Health Sci. 2006;13(1–2):28–32. Bassey BE, Gasasira A, Mitula P, Frankson UU, Adeniji JA. Surveillance of Acute Flaccid Paralysis in Akwa Ibom State, Nigeria 2004–2009. Pan Afr Med J. 2011;9:32. Odoom JK, Ntim NAA, Sarkodie B, Addo J, Minta-Asare K, Obodai E, Eshun M, Ahove VV, Diamenu S, Adjabeng M, Arthur-Quarm J, Barnor JS. Evaluation of Afp Surveillance Indicators in Polio-Free Ghana, 2009–2013. BMC Public Health. 2014;14:687–94. Chirambo RM, Baboo KS, Siziya S. Performance of Acute Flaccid Paralysis Surveillance System in Zambia: 2000 to 2009- Analysis of Secondary Data. International Journal of Public Health Epidemiology. 2014;3(10):075–81. WHO. Best Practices in Active Surveillance for Polio Eradication. WHO. Who Recommended Surveillance Standards. Geneva: World Health Organization, Department of Communicable Disease Surveillance and Response; 1999. Pomerai KW, Mudyiradima RF, Tshimanga M, Muchekeza M. Evaluation of the Acute Flacid Paralysis (Afp) Surveillance System in Bikita District Masvingo Province 2010. BMC Research Notes. 2014;7:252–58. Lam RMK, Tsang THF, Chan KY, Lau YL, Lim WL, Lam TH, Leung NK. Surveillance of Acute Flaccid Paralysis in Hong Kong: 1997 to 2002. Hong Kong Medical Journal. 2005;11(3):164–73. Bessaud M, Joffret M-L, Blondel B, Delpeyroux F. Exchanges of Genomic Domains between Poliovirus and Other Cocirculating Species C Enteroviruses Reveal a High Degree of Plasticity. Sci Rep. 2016;6(1):38831. Bassey B, Fiona B, Muluh T, William K, Toritseju M, Oyetunji A, Ubong A, Okocha-Ejeko A. Distribution Pattern of the Non Polio Enterovirus (Npev) Rate in Children with Acute Flaccid Paralysis Reported to the Surveillance System in Nigeria 2010–2015. Health. 2018;10:907–18. Cite Share Download PDF Status: Under Review Version 1 posted Review # 2 received at journal 06 Mar, 2021 Editorial decision: Major revision 06 Mar, 2021 Reviewer # 2 agreed at journal 06 Dec, 2020 Review # 1 received at journal 29 Nov, 2020 Reviewers invited by journal 28 Nov, 2020 Reviewer # 1 agreed at journal 28 Nov, 2020 Editor assigned by journal 26 Nov, 2020 Submission checks completed at journal 26 Nov, 2020 Editor invited by journal 26 Nov, 2020 First submitted to journal 26 Oct, 2020 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-117324","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":5460744,"identity":"0d9d6a1e-0c39-42ca-adb5-e47ab18f1050","order_by":0,"name":"Ismail Abdullateef Raji","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAklEQVRIie2PMWuDQBiGPxEui91vu7/wQeBwEP0hWRTBLCk4dnCwCMlfyNZfUAgEOh8c2CXENZAl/gOhS4dC+ynipnYM5B6O44b34X0PwGC4UxSk/YujR7f1qibzrFVwUJJWyWcVGBQA3fdOIN6KWqfoBSJ/qhs3rfz3naaWzFuNKVgy1HtMooNaLDnHa/xxikgpk+d8TGGA2kEdIk3sFKlIsXI9qojtoiHll4Yx+5vjOZZVPa1A6bQtlFGMUYvy5WWmBctNSkocHTRjLsc4lBdqCSf+IorP45fz4gdit7Wv/McPZLWub03mjQ8bsOlwgKhLhrPxHqsBCP4bNhgMhsfhD7zjW8foEMNIAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-1113-0877","institution":"Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Ismail","middleName":"Abdullateef","lastName":"Raji","suffix":""},{"id":5460745,"identity":"fc564ed3-affa-4db1-95f3-e2fcfcc0e337","order_by":1,"name":"Auwal Abubakar Usman","email":"","orcid":"","institution":"Department of Community Medicine, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Auwal","middleName":"Abubakar","lastName":"Usman","suffix":""},{"id":5460746,"identity":"50b94d20-36f2-4430-8e8b-73e71b8d0a7c","order_by":2,"name":"Abdulrahman Ahmad","email":"","orcid":"","institution":"Department of Public Health, Ministry of Health, Sokoto, Nigeria","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Abdulrahman","middleName":"","lastName":"Ahmad","suffix":""},{"id":5460747,"identity":"3771ba76-5c76-484b-8a32-0d41ef23a3e3","order_by":3,"name":"Saheed Gidado","email":"","orcid":"","institution":"National Stop Transmission of Polio, Abuja, Nigeria","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Saheed","middleName":"","lastName":"Gidado","suffix":""},{"id":5460748,"identity":"2f38cf96-ea91-403b-b21c-55912d851b53","order_by":4,"name":"Abdulhakeem Abayomi Olorukooba","email":"","orcid":"","institution":"Department of Community Medicine, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Abdulhakeem","middleName":"Abayomi","lastName":"Olorukooba","suffix":""},{"id":5460749,"identity":"312ba0b1-b6d1-44af-b01e-6aff762d1e93","order_by":5,"name":"Bola Biliaminu Lawal","email":"","orcid":"","institution":"Department of Community Medicine, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Bola","middleName":"Biliaminu","lastName":"Lawal","suffix":""},{"id":5460750,"identity":"3392bd1e-f3c4-4c86-9698-74373dd75fba","order_by":6,"name":"Chukwuma David Umeokonkwo","email":"","orcid":"","institution":"Department of Community Medicine, Alex Ekwueme Federal University Teaching Hospital, Ebonyi, Nigeria","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Chukwuma","middleName":"David","lastName":"Umeokonkwo","suffix":""},{"id":5460751,"identity":"762b1737-7983-4df4-8f4f-c071bf2aad33","order_by":7,"name":"Muhammad Balogun","email":"","orcid":"","institution":"Nigerian Field Epidemiology and Laboratory Training Program, Abuja, Nigeria","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Muhammad","middleName":"","lastName":"Balogun","suffix":""}],"badges":[],"createdAt":"2020-11-27 16:15:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-117324/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-117324/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":3993676,"identity":"2690a123-ffa9-49bc-86fc-4944a17abd4b","added_by":"auto","created_at":"2020-12-03 17:29:28","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":44682,"visible":true,"origin":"","legend":"Flow chart of AFP surveillance system. CIF - Case Investigation Form, DSNO - Disease Surveillance and Notification Officer, FMoH - Federal Ministry of Health, NPHCDA - National Primary Health Care Development Agency, NIO - National Immunization Officer, NPEC: National Polio Expert Review Committee, SE: State Epidemiologist, WHO SO - World Health Organization Surveillance Officer","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-117324/v1/65e9ebe562bd6c2d12cac8da.png"},{"id":3993677,"identity":"b0f23640-26cd-463a-b562-5883a7b1b1d3","added_by":"auto","created_at":"2020-12-03 17:29:29","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":20273,"visible":true,"origin":"","legend":"Proportion of cases seen in the LGAs in Sokoto state, 2012-2019","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-117324/v1/b2f07673117f8732602370c8.png"},{"id":3993678,"identity":"d7b2aee3-179c-4bc6-a5de-aea531f0ecdc","added_by":"auto","created_at":"2020-12-03 17:29:29","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":103153,"visible":true,"origin":"","legend":"Annualised non-polio AFP rate by LGA for each year in Sokoto state, 2012-2019","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-117324/v1/08946d3c670230bf25fd2935.png"},{"id":3993679,"identity":"aabec385-cc13-4a06-bb10-55265d8c0af5","added_by":"auto","created_at":"2020-12-03 17:29:29","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":28153,"visible":true,"origin":"","legend":"Stool adequacy rate by LGA for each year in Sokoto state, 2012-2019","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-117324/v1/c51edf137175902935c1a547.png"},{"id":13621530,"identity":"bb7f3c74-9024-4369-bdc4-9a007bffb61a","added_by":"auto","created_at":"2021-09-17 07:11:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":803068,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-117324/v1/0c52f282-466a-42fc-b6e6-be78106dcef5.pdf"}],"financialInterests":"","formattedTitle":"Evaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis","fulltext":[{"header":"Introduction","content":" \u003cp\u003eWild Polio Virus (WPV) is a highly contagious viral disease that leads to poliomyelitis which mainly affects children below five years [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. It transmitted human to human, mainly via the orofaecal route [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Out of 200 cases of poliovirus infection, one would lead to irreversible floppiness a limb (usually the lower extremities). Among those paralyzed, up to 10% die as a result of the failure of the respiratory muscles [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFollowing the introduction of the Global Polio Eradication Initiative in 1988, the proportion of new cases of paralysis due to WPV infection has dropped to less than one per cent [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe polio searchlight of the world is now on Pakistan and Afghanistan, as Nigeria was recently declared free of poliomyelitis [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Eliminating the poliovirus in the remaining endemic countries would have led to the biggest-ever internationally-coordinated open wellbeing exertion in history [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePoliomyelitis is of public health importance because it is among the few diseases that can be eradicated with cheap and effective vaccines [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. To eradicate polio, every child must receive the polio vaccine. The vaccination should include those living in remote and underserved areas and in conflict zones like Borno state in Nigeria (where the last case in Nigeria was reported in 2016) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The presence of just a child with poliovirus puts children worldwide at risk of contracting the virus. The continuous endemicity of poliovirus in certain countries may result in as numerous as 200 thousand new WPV cases each year and if unchecked may affect every continent within ten years [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Worse of all, once poliovirus causes paralysis, there is no cure [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAcute Flaccid Paralysis (AFP) cases present with similar symptoms and signs with poliomyelitis; hence, AFP surveillance is used worldwide as an approach for monitoring and evaluating the achievements of polio eradication initiative [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Sensitive AFP surveillance is able to detect all cases of poliomyelitis for immediate public health action. In countries that have been certified polio-free, effective AFP surveillance is a strategy to continually evaluate the absence of transmission [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In countries that are not yet declared polio-free, surveillance plays a central role in the eradication process [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Therefore, high-quality AFP surveillance system is needed in proving and maintain the successful interruption of WPV [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eNigeria and indeed, entire Africa has been certified free of WPV [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. However, the continent is still at risk of importation of WPV from Pakistan and Afghanistan, especially in states like Sokoto, which has international borders. Furthermore, the rare form of the poliovirus, the circulating Vaccine Derived Polio Virus (cVDPV) is affecting communities in Africa that are under-immunized, especially among hard to reach communities, migrant population, and those in conflict zones [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. This is the case in Sokoto state where in the last one year, the state has recorded 6 cases of cvDPV2 from different sources \u0026ndash; an indication of low population immunity and favourable factors for the transmission of cVPDVs [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Therefore, it is essential to continuously ensure that the AFP surveillance in Sokoto state is reliable enough to guide public health response towards the eradication of cVDPV in the context of the polio endgame strategic plan 2019 to 2023 [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTherefore, this study describes the findings from an eight-year AFP surveillance in Sokoto State and assesses the performance of the system with respect to the World Health Organization (WHO) surveillance indicators besides identifying the aspects that need improvement.\u003c/p\u003e "},{"header":"Methods","content":" \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy setting and design\u003c/h2\u003e \u003cp\u003eSokoto state is located in Northwest Nigeria, covering about 27,825\u0026nbsp;km\u003csup\u003e2\u003c/sup\u003e [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. It shares a border with the Niger Republic to the North \u0026ndash; making it prone to cross border importation of poliovirus[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], Zamfara state to the south and east, and Kebbi state to the west and south. The state has 23 Local Government Areas (LGAs) out of which four are metropolitan. The projected population of Sokoto state for the year 2019 using a growth rate of 3.01% from the 2006 national census \u003csup\u003e[13]\u003c/sup\u003e was 5,475,895, with children under-five and under-15\u0026nbsp;years having a projected population of 114,069 and 268,1364 respectively. The state has a substantial nomadic population who are polio high-risk group [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \n\u003ch2\u003eDescription Of The Afp Surveillance System In Sokoto State\u003c/h2\u003e\n \u003cp\u003eThe mode of operation of the Sokoto state AFP surveillance system is similar to the other 35 states and the Federal Capital Territory, and it is part of the broader AFP surveillance system in Nigeria (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In the surveillance system, an AFP case is defined as \"Any child under 15\u0026nbsp;years of age with the acute (sudden) onset of weakness or floppiness of one or more limbs or any person of any age with paralytic illness in whom a clinician suspects poliomyelitis\" [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe primary purpose of the AFP surveillance system in Sokoto state is to detect and document the presence or absence of Wild Polio Virus in the state. The objectives of the AFP surveillance system in Sokoto state include:\u003c/p\u003e \u003cp\u003e \u003col\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eTo provide data-driven evidence that guides the advancement of strategies that lead to polio eradication.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eTo identify areas of cVDPV in Sokoto state.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eTo investigate all detected AFP cases and demonstrate the non-transmission of WPV in Sokoto state.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eTo assess the effect of Routine Immunization Activities (RIAs) and Supplementary Immunization Activities (SIAs) against polio.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e \u003cp\u003eThe flow of data in the AFP surveillance in Sokoto state begins with the notification of every case by community informants (such as traditional bone setters) or the health facility focal persons to their respective LGA Disease Surveillance and Notification Officers (DSNOs). The DSNOs are responsible for ensuring that adequate stool samples are collected from suspected cases. They are also responsible for ensuring that the samples get to the national polio laboratory in Ibadan, Oyo state in optimal temperature accompanied with correctly filled AFP Case Investigation Forms (CIFs). The LGA DSNO has an assistant DSNO, and he is also supported by an LGA facilitator who is on the WHO payroll. The LGA DSNO is responsible for giving regular feedback to the reporting facilities, focal persons and communities.\u003c/p\u003e \u003cp\u003eThe state epidemiologist and the state DSNO facilitate and oversee the activities of the LGA DSNO. The WHO cluster consultants assigned to different LGAs are responsible for verifying the suspected cases and conducting 60-day follow-up for cases that were not investigated within 14 days of onset of paralysis. The state epidemiologist gives feedback to the LGAs and reports to the Nigeria Center for Disease Control (NCDC), National Primary Health Care Development Agency (NPHCDA), Federal Ministry of Health (FMoH); and the state DSNO gives feedback to the LGAs on laboratory results (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe funding of AFP surveillance System in Sokoto State is by the federal government, Sokoto state government, and LGAs with robust technical and financial support by development partners notably, WHO and Centers for Disease Control and Prevention (CDC) / Africa Field Epidemiology Network (AFENET). WHO sponsors the active case finding visits by DSNOs to AFP reporting sites. Additionally, the organization supports the DSNOs with transportation allowances to attend the monthly surveillance meetings at the states' capital. CDC/AFENET provides technical and human resource support to all the LGAs to complement Government resources.\u003c/p\u003e \n\u003ch2\u003eStudy Design\u003c/h2\u003e\n \u003cp\u003eWe conducted a retrospective descriptive analyses of AFP surveillance data in Sokoto state from January 2012 to December 2019. We included AFP cases reported in all the LGAs within the period in this study. We evaluated the AFP performance using the WHO indicators for assessing the AFP surveillance system [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \n\u003ch2\u003eData Collection And Analysis\u003c/h2\u003e\n \u003cp\u003eWe sieved out information on age, gender, Oral Polio vaccine (OPV) doses, fever at the onset, asymmetry of paralysis, the progression of paralysis in 3 days and classification as true AFP. All analyses were done using Microsoft Excel version 2019. We conducted descriptive analyses and generated core performance indicators and other indicators recommended by the WHO for assessing the AFP surveillance system [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e "},{"header":"Results","content":" \u003cp\u003eIn total, 3001 AFP cases were identified and reported by the AFP surveillance system in Sokoto between January 2012 and December 2019. Out of these, more than half, 1692 (56.4) were males, and more than three-quarters, 2478 (82.4%) were less than five years old. Almost all, 2959 (98.6%) had taken three or more OPV doses. More than half, 1773 (59.1%) had a fever at the onset of the disease, and many 1911 (63.7%) had asymmetric paralysis. More than one-third, 1178 (39.3) of cases had a progression of paralysis in 3\u0026nbsp;days (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Illela LGA had the highest proportion of cases cases, 251 (8.4%); while Tureta LGA had the least number of cases, 72 (2.4%) over the evaluation period (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eCumulatively, the Sokoto State annualized non-polio AFP detection rate was 16.7 AFP cases per 100,0000 population below 15 years, indicating a sensitive AFP surveillance. Over the evaluation period, the annualized non-polio AFP rate was consistently above the minimum target of \u0026ge;\u0026thinsp;2/100,000 in the state. (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Disaggregating the state cumulative non-polio AFP rate by LGAs showed that all the LGAs consistently surpassed the WHO minimum of 2 AFP cases per 100, 000 population of children below 15\u0026nbsp;years during the 8\u0026nbsp;years evaluation period (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThere was a consistent increase in the proportion of AFP cases with adequate stools from 92.5% in 2012 to 100% in 2016 and a drop to 96% in 2018 and 2019. Over the evaluation period, the stool adequacy performance was above the minimum target of 80% for the state (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Disaggregated by LGAs, all the LGAs met the minimum standard except, Kware, 67% in 2012; Yabo, 71% in 2018 and Tangaza, 75% in 2019 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAll stool samples arrived at the laboratory within 72 hours of being sent during the evaluation period (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The laboratory performance indicator, Non-polio Enterovirus (NPENT) rate, was above the minimum level required over the 8-year evaluation period. (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eProfile of the AFP cases reported in Sokoto state, Nigeria, 2012\u0026ndash;2019\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eProfile\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNumber of AFP cases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePercent\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e(n\u0026thinsp;=\u0026thinsp;3001)\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge group (years)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026le;\u0026thinsp;5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2478\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e82.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\u0026ndash;10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e383\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11\u0026ndash;15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUnknown age status\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGender\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale \u0026lrm;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1692\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e56.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1309\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e43.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOPV doses\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2959\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e98.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFever at onset\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1773\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e59.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMissing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAsymmetry\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1911\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e415\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMissing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e541\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eProgression in 3 days\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1178\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e39.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMissing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1771\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e59.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eClassified as true AFP\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1187\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e39.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMissing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1783\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e59.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003csup\u003eAFP performance indicators for Sokoto State, Nigeria, 2012\u0026ndash;2019\u003c/sup\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"10\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePerformance indicator\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTarget\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"8\" nameend=\"c10\" namest=\"c3\"\u003e \u003cp\u003eState performance\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2012\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e2013\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2014\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e2015\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e2016\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e2017\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e2018\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003e2019\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnnualized non-polio AFP rate /100,000\u0026thinsp;\u0026lt;\u0026thinsp;15\u0026nbsp;years population\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e23.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e19.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e21.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e11.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e9.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProportion of AFP cases with two adequate stool specimens\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;80%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e92.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e99.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e99.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e96.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e96.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTimeliness of monthly reporting\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;80%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e96\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ecompleteness of monthly reporting\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;90%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProportion of AFP cases investigated within 48 hours of notification\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;80%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e98.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e99.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReported AFP cases with follow-up exam at least 60 days after paralysis onset.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;80%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e80.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe proportion of specimens that arrived at a WHO accredited laboratory\u0026thinsp;\u0026lt;\u0026thinsp;3 days of being sent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;80%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProportion of stool specimens arriving at the laboratory in good condition\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;80%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e99.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e99.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e99.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProportion of stool specimens from which non-polio enterovirus was isolated NPENT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;10%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAFP surveillance index\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e23.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e19.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e21.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e11.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e8.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e "},{"header":"Discussion","content":" \u003cp\u003eThis study involved a state-wide analysis of AFP surveillance data in Sokoto State and reports the findings of the evaluation of APF surveillance indicators from 2012\u0026ndash;2019. Over the evaluation period, we found that children below five years were most affected, with over 80% of the cases. This finding corroborates what has been stated by WHO that under-five children are most affected [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. The finding indicates that the AFP surveillance system is identifying the primary age group affected. The finding in this study is comparable to what was reported in the evaluation of surveillance system in Ibadan (74.3%)[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] and in Akwa Ibom (82.5%)[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] states in Nigeria and Ghana(76.3%) [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, a surveillance system evaluation in Zambia showed that 63% of cases were in the age group 10\u0026ndash;15\u0026nbsp;years [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]; although a significant proportion of the cases did not have their age documented in the study which could have been responsible for their finding. More than half (56.7%) of the AFP cases observed in this evaluation were males. This finding is similar to what was reported in Ghana (55.8%)[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] and South Africa (54.3%) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlmost all the AFP cases have had at least three doses of OPV through RIAs and SIAs activities. This is encouraging because it is an indication that Sokoto State is implementing the global polio eradication strategies. A similar finding was reported in the surveillance system evaluation in Ghana [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Worthy of note in the surveillance data was that some characteristics of the AFP cases were not documented. For example, 38.3% of the cases did not have documentation presence of fever at the onset of paralysis, and 59% did not have documentation on the progression of paralysis. This information is essential in determining whether a case is a \"hot\" case or not [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Therefore, this poor quality of data can affect the performance of the surveillance system.\u003c/p\u003e \u003cp\u003eMaintaining a sensitive surveillance system that can detect WPV is critical in the eradication of poliomyelitis by enabling early response to importations and in certifying the complete interruption of transmission [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. A well-performing AFP surveillance system should be able to pick a minimum of two AFP cases per 100,00 children younger than 15\u0026nbsp;years [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. This is used as a proxy of the sensitivity of AFP surveillance system. This indicator measures the capacity of the surveillance system to detect AFP cases due to other causes than polio [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. In this study, we found the AFP surveillance system in Sokoto to be sensitive. The minimum standard for non-polio AFP rate was surpassed throughout the period under review. It is crucial to monitor LGA performance because, state-level indicators may mask wide variation in LGA performance,[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] therefore, we disaggregated the data by LGA, and we found that all LGAs performed above the minimum standard. This finding is encouraging as Nigeria is no more an endemic country for polio transmission [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]; therefore, any reintroduction can be picked by the sensitive AFP surveillance system. This finding is especially important because Sokoto State has an international border. A similar finding was reported in Zambia, where the AFP detection rate was consistently above the national target for over five years of surveillance evaluation [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The finding our study is contrary to what was reported in a surveillance evaluation in Zimbabwe, where it was found not to be sensitive [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In South Africa, an increasing trend in the sensitivity of the AFP surveillance system was observed over five years \u0026ndash; between 2005 and 2009; however, the target was only met in 2008 [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eA stool specimen is adequate if collected 24\u0026ndash;48 hours apart and within two weeks of the onset of paralysis and arriving at the laboratory in good condition [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. The results from this surveillance evaluation showed that the proportion of stool samples adequately collected throughout the evaluation period was consistently above the minimum standard of 80%. After disaggregating, all LGAs performed well, except 3 LGAs (Kware in 2012, Yabo in 2018 and Tangaza in 2019). This finding could be an indication that the community and parents are aware of the AFP surveillance system, leading to early detection and reporting. The finding could also be an indication that there are minimal causes of delays such as lack of involvement of health workers or inadequate logistics such as stock-out of kit sand transport.\u003c/p\u003e \u003cp\u003eThe non-polio AFP rate and the stool adequacy rate are used as the standard for assessing the quality of AFP surveillance [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. These two indicators can be combined into a single indicator of AFP surveillance quality, the surveillance index, which can be used to compare progress over time and or geographic differences [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. In this surveillance evaluation, the surveillance index for the state was greater than 2.5, indicating a robust AFP surveillance on average [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Using this index in maps helps in identifying areas of risk. Fortunately, in Sokoto State, no area of risk was identified using this index. The success in the surveillance index could be due to the regular capacity building and financial support provided by the WHO to the LGA DSNOs.\u003c/p\u003e \u003cp\u003eIn addition to finding AFP cases, timeliness, and the quality of investigation of suspected cases are also vital in achieving the objectives of an AFP surveillance system. Stool samples were collected from almost all the suspected cases within 48 hours of notification. This could be attributed to proper training and supervision from WHO cluster consultants in the various LGAs in the state.\u003c/p\u003e \u003cp\u003eLaboratory investigation is fundamental to the confirmation of WPV; therefore, the integrity of the faecal samples arriving the laboratory should be good enough for laboratory confirmation of the presence or absence of the virus with a reasonable level of certainty. No WPV was isolated in Sokoto State during the evaluation period; therefore, with the high stool adequacy rate, any form of poliovirus transmission will be most likely picked by the AFP surveillance in Sokoto state. The finding in this study defers from what was reported in the evaluation done in North Korea, where stool adequacy was consistently lower than the WHO recommended standard of 80% [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo maximize the opportunity to isolate the poliovirus, with the highest probability occurring within the first 14 days, some indicators of AFP surveillance assess the timeliness of certain surveillance activities [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. A minimum of 80% of faecal samples should reach the laboratory within three days of sample collection. [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. The result from this evaluation revealed that in Sokoto State, all the stool samples were received in the laboratory within three days during the evaluation period. This positive finding could be a result of the stipend given to any surveillance officers who transport the samples to the laboratory. A contrary finding was reported in South Africa were the WHO minimum target was not met with regards to the timeliness of transportation of samples to the laboratory [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The finding could be because, in South Africa, courier services were used, which could experience some delays; however, in Nigeria, Sokoto State inclusive, the LGA DSNOs are responsible for the immediate transportation of the sample to the laboratory.\u003c/p\u003e \u003cp\u003eVery pivotal in the detection of poliovirus is the arrival of the stool samples in the laboratory within three days and samples being in good condition. These indicators also assess the timeliness of surveillance activities [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. In this evaluation, at least 99 per cent of samples reached the designated laboratory in perfect condition, and all samples arrived at the laboratory within three days. This finding gives a high degree of confidence that whatever findings in the laboratory reflect the actual situation. This positive finding could be attributed to the frequent sponsored training on polio surveillance activities by WHO in the state, close monitoring of surveillance activities by cluster consultants and provision of stipends for surveillance officers. The AFP surveillance system met the target for timeliness of monthly reporting over the evaluation period. This finding is important because this allows the state to take all necessary early actions to ensure polio certification.\u003c/p\u003e \u003cp\u003eThe NPENT rate to assesses how the AFP surveillance system can maintain the reverse cold chain. It also to assesses the performance of the laboratories in the routine isolation of enteroviruses [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Sokoto state has performed well in this indicator over the evaluation period by exceeding the minimum value of 10%. This finding is important, especially in the post-polio era in Sokoto state, which still reports cVDPVs. It has been established that cVDPVs have the potential to combine and recombine with other enteroviruses, which can give rise to new strains of pathogenic [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Therefore, adequate NPENT surveillance will help detect and control any outbreak. Similar NPENT rates were recorded in the neighbouring Kebbi state between 2010 and 2015 [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAn area of deficiency observed in this secondary data analysis is that the surveillance data obtained had no information on the timeliness of specimen processing. So we could not assess if stool sample results were sent back within 28 days of receipt of samples in the laboratory. It is essential to document this information as this will allow for assessment of the feedback channel.\u003c/p\u003e \u003cp\u003eOverall, the AFP surveillance indicators are meeting-up with the minimum targets. However, this should not create a state of complacency as it was observed in Jigawa state in 2011 where all the minimum standard for certification were surpassed, but following analyses of environmental samples, WPV and cVDPV were detected, indicating that certain chains of transmission had been missed [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Therefore, surpassing most of the surveillance indicator targets should not allow lowering of surveillance guards.\u003c/p\u003e "},{"header":"Conclusion","content":" \u003cp\u003eThe AFP Surveillance system in Sokoto State has performed well over the past eight years by exceeding the minimum WHO targets both at the state and LGA levels. The system is sensitive enough to detect any importation of new cases into the polio-free Sokoto. However, there is inadequate documentation of laboratory results and some profile information on the suspected cases. We recommend that the state ministry of health should ensure that data managers document whether laboratory results return within 28\u0026nbsp;days of receiving the samples in the laboratory.\u003c/p\u003e "},{"header":"Abbreviations","content":" \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e \u003ccolgroup cols=\"2\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAFENET\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAfrica Field Epidemiology Network\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAFP\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAcute Flaccid Paralysis\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCDC\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCentres for Disease Control and Prevention\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCIFs\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCase Investigation Forms\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ecVDPV\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ecirculating Vaccine Derived Polio Virus\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDSNOs\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDisease Surveillance and Notification Officers\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFMoH\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFederal Ministry of Health\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLGAs\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLocal Government Areas\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNCDC\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNigeria Center for Disease Control\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNPENT\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-polio Enterovirus\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNPHCDA\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNational Primary Health Care Development Agency\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOPV\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOral Polio vaccine\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRIAs\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eImmunization Activities\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSIAs\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSupplementary Immunization Activities\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWPV\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWild Polio Virus\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e: We sought ethical approval from Sokoto State Ministry of Health Research Ethics Committee before the commencement of the study. We protected the confidentiality of patients by using special codes. We expunged all personal identifying information from the data used. Data security was maintained using a password-protected computer.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication: \u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials: \u003c/strong\u003eThe datasets generated analyzed during the current study are not publicly available because it is the property of Sokoto state Ministry of Health; however, the data but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDr Chukwuma David Umeokonkwo\u003csup\u003e, \u003c/sup\u003eone of the authors of this manuscript is a member of the BMC Public Health editorial board member.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors of this study funded this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIAR participated in conceptualization, analyses, writing original draft, and review and editing. AAU was involved in conceptualization, analyses and interpretation of data, review and editing Abdulrahman participated in data acquisition, analyses and interpretation of data. BBL contributed to conceptualization, analyses and interpretation of data, review and editing. CDU was involved in methodology, review and editing. AAO contributed to methodology, review and editing. SG was involved in conceptualization, methodology and review and editing. MB supervised the manuscript writing, review \u0026amp; editing. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe are grateful to the World Health Organization, Sokoto for their contribution to data gathering in the state. The Nigerian Field Epidemiology and Training program for their technical guidance and manuscript writing workshop.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eNigerian Field Epidemiology and Laboratory Training Program, Abuja, Nigeria. \u003csup\u003e2\u003c/sup\u003eDepartment of Community Medicine, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria\u003cbr /\u003e\u003csup\u003e3\u003c/sup\u003eDepartment of Public Health, Ministry of Health, Sokoto\u003cbr /\u003e\u003csup\u003e4\u003c/sup\u003eNational Stop Transmission of Polio, Nigeria. \u003cbr /\u003e\u003csup\u003e5\u003c/sup\u003eDepartment of Community Medicine, Ahmadu Bello University, Zaria, Nigeria.\u003cbr /\u003e\u003csup\u003e6\u003c/sup\u003eDepartment of Community Medicine, Alex Ekwueme Federal University Teaching Hospital, Ebonyi, Nigeria.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWHO. 10 Facts on Polio Eradication. 2016. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.who.int/features/factfiles/polio/facts/en/index.html\u003c/span\u003e\u003c/span\u003e. Accessed 3 November 2019.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCDC. Manual for the Surveillance of Vaccine-Preventable Diseases. Centers for Disease Control and Prevention, Atlanta, GA.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCDC. Updates on Cdc's Polio Eradication Efforts. 2016. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.cdc.gov/polio/updates/\u003c/span\u003e\u003c/span\u003e. 2019.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO. Global Polio Eradication Initiative Applauds Who African Region for Wild Polio-Free Certification. 2020. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/news-room/detail/25-08-2020-global-polio-eradication-initiative-applauds-who-african-region-for-wild-polio-free-certification\u003c/span\u003e\u003c/span\u003e. Accessed 26th August 2020 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO. Poliomyelitis -Fact Sheets 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.who.int/mediacentre/factsheets/fs114/en/\u003c/span\u003e\u003c/span\u003e. Accessed 2nd January 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTangermann RH, Lamoureux C, Tallis G, Goel A. The Critical Role of Acute Flaccid Paralysis Surveillance in the Global Polio Eradication Initiative. International Health. 2017;9(3):156\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlobal Polio Eradication Initiatitve. Surveillance 2010. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp-//www.polioeradication.org/AboutUs/Strategy/Surveillance.aspx\u003c/span\u003e\u003c/span\u003e. Accessed Sep 26th 2016.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhuzwayo LS, Kuonza LR, Ngcobo NJ. Evaluating the Acute Flaccid Paralysis Surveillance System in South Africa, 2005-2009-an Analysis of Secondary Data. Pan Afr Med J. 2013; 14(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO. Polio. 2020. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.afro.who.int/health-topics/polio\u003c/span\u003e\u003c/span\u003e. Accessed 14th August 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHPSC. Acute Flaccid Paralysis Surveillance: What Is It and Why Are We Doing It?: Health Protection Surveillance Centre. 2013.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlobal Polio Eradication Initiatitve. Gpei Strategy for Control of Cvdpv2 2020. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://polioeradication.org/wp-content/uploads/2020/07/cVDPV2-nOPV2-fact-sheet-July-2020.pdf\u003c/span\u003e\u003c/span\u003e. Accessed 3 September 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO, GPEI. Polio Endgame Strategy 2019\u0026ndash;2023: Eradication, Integration, Certification and Containment. Geneva: World Health Organization; 2019.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNational Bureau Of Statistics. Annual Abstract of Statistics: Federal Republic of Nigeria. 2011.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBawa S, Afolabi M, Abdelrahim K, Abba G, Ningi A, Tafida SY, Tegegne SG, Warigon C, Nomhwange T, Umar SA, Aregay A, Fanti A, Ahmed B, Nsubuga P, Adamu U, Braka F, Wondimagegnehu A, Shuaib F. Transboundary Nomadic Population Movement: A Potential for Import-Export of Poliovirus. BMC Public Health. 2018;18(Suppl 4):1316\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNational Primary Health Care Develoement Agency and Partners. Gudielines for Poliovirus Surveillance Nigeria. June 2019 ed.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO. Who Recommended Standards for Surveillance of Selected Vaccine-Preventable Diseases. Geneva: Department of Vaccines and Biologicals, Health Technology and Pharmaceuticals, World Health Organization; 2003.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO. Poliomyelitis 2019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/news-room/fact-sheets/detail/poliomyelitis\u003c/span\u003e\u003c/span\u003e. Accessed 17th June 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamzat T-hK, Omotade TT. Acute Flaccid Paralysis: A Five\u0026ndash;Year Review of Cases Managed by Physiotherapy at the University College Hospital, Ibadan. Afr J Health Sci. 2006;13(1\u0026ndash;2):28\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBassey BE, Gasasira A, Mitula P, Frankson UU, Adeniji JA. Surveillance of Acute Flaccid Paralysis in Akwa Ibom State, Nigeria 2004\u0026ndash;2009. Pan Afr Med J. 2011;9:32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOdoom JK, Ntim NAA, Sarkodie B, Addo J, Minta-Asare K, Obodai E, Eshun M, Ahove VV, Diamenu S, Adjabeng M, Arthur-Quarm J, Barnor JS. Evaluation of Afp Surveillance Indicators in Polio-Free Ghana, 2009\u0026ndash;2013. BMC Public Health. 2014;14:687\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChirambo RM, Baboo KS, Siziya S. Performance of Acute Flaccid Paralysis Surveillance System in Zambia: 2000 to 2009- Analysis of Secondary Data. International Journal of Public Health Epidemiology. 2014;3(10):075\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO. Best Practices in Active Surveillance for Polio Eradication.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWHO. Who Recommended Surveillance Standards. Geneva: World Health Organization, Department of Communicable Disease Surveillance and Response; 1999.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePomerai KW, Mudyiradima RF, Tshimanga M, Muchekeza M. Evaluation of the Acute Flacid Paralysis (Afp) Surveillance System in Bikita District Masvingo Province 2010. BMC Research Notes. 2014;7:252\u0026ndash;58.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLam RMK, Tsang THF, Chan KY, Lau YL, Lim WL, Lam TH, Leung NK. Surveillance of Acute Flaccid Paralysis in Hong Kong: 1997 to 2002. Hong Kong Medical Journal. 2005;11(3):164\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBessaud M, Joffret M-L, Blondel B, Delpeyroux F. Exchanges of Genomic Domains between Poliovirus and Other Cocirculating Species C Enteroviruses Reveal a High Degree of Plasticity. Sci Rep. 2016;6(1):38831.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBassey B, Fiona B, Muluh T, William K, Toritseju M, Oyetunji A, Ubong A, Okocha-Ejeko A. Distribution Pattern of the Non Polio Enterovirus (Npev) Rate in Children with Acute Flaccid Paralysis Reported to the Surveillance System in Nigeria 2010\u0026ndash;2015. Health. 2018;10:907\u0026ndash;18.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-public-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pubh","sideBox":"Learn more about [BMC Public Health](http://bmcpublichealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pubh/default.aspx","title":"BMC Public Health","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"AFP, Poliomyelitis, Evaluation, Surveillance, Indicators, Sokoto, Nigeria ","lastPublishedDoi":"10.21203/rs.3.rs-117324/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-117324/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eNigeria and indeed, entire Africa has been certified free of Wild Polio Virus (WPV) in 2020. However, the continent is still at risk of importation of WPV, especially in states like Sokoto in Nigeria, which has an international border.\u0026nbsp;Furthermore, due to low immunity in some communities in Sokoto, outbreaks of the circulating Vaccine Derived Polio Virus (cVDPV) occur. Therefore, this paper evaluates the Acute Flaccid Paralysis (AFP) surveillance indicators in Sokoto state, Nigeria. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eThis retrospective study was an analysis of routinely collected AFP surveillance data between 2012 and 2019 by the Sokoto state surveillance network. We assessed the Sokoto state AFP surveillance system using the AFP surveillance performance indicators. We performed all analyses using Microsoft Excel 2019.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Cumulatively, 3001 Acute Flaccid Paralysis (AFP) cases were reported over the evaluation period, out of which 1692 (56.4%) were males, and 2478 (82.4%) were below five years. More than half, 1773 (59.1%) had a fever at the beginning of the disease, and 1911 (63.7%) had asymmetric paralysis. \u0026nbsp;The non-polio AFP rate (9.1 to 23.5%) and stool adequacy rate (92.5 to 100%) indicate high sensitivity. The proportion of cases that had stool samples collected early, timely transported to the laboratory and arrived at the laboratory in optimal condition were all above the World Health Organization (WHO) minimum standard of 80%.\u0026nbsp;There was inadequate profile documentation of some suspected cases.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusions: \u003c/strong\u003e\u0026nbsp;Sokoto State has exceeded the WHO minimum standards in most of the AFP surveillance indicators. The performance of the system is sufficient enough to detect any reintroduction of WPV into the state. \u0026nbsp;However, there is a need for improvement in data quality.\u003c/p\u003e","manuscriptTitle":"Evaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2020-12-03 17:25:11","doi":"10.21203/rs.3.rs-117324/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2021-03-07T00:00:00+00:00","index":2,"fulltext":"Recommendation: Major revisions required\nForm responses:\n---\n\nComments to Author:\n---\nPReview:\nEvaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis\nThe Global Polio Eradication Initiative (GPEI) has been making great strides to achieve mass elimination worldwide of WPV circulation and the surveillance and curtailing of VDPV .\nIn 2020, the number of children reported with paralysis caused by wild-type poliovirus 1 was higher than previous years (132 ) in the 2 endemic countries ( Pakistan and Afghanistan) possibly due to pandemic under detection of infectious diseases other than COVID-19.\nLast WPV type 3 had its onset on 10 November 2012. Nigeria was declared Wild polio-free as of June 2020.\nHowever, the polio endgame is complex and challenging. The oral poliovirus vaccine (OPV) used in mass campaigns to stop transmission of wild polioviruses is genetically unstable and on rare occasions can evolve to regain wildtype virulence and transmissibility. This has resulted in outbreaks of poliomyelitis caused by vaccine-derived polioviruses, which have gained in significance over time relative to the declining burden of wild-type disease. The global withdrawal of OPV began in April 2016 and trivalent inactivated poliovirus vaccine (IPV) was introduced into the routine immunization schedule in countries previously relying solely on OPV for protection.\nThe successful eradication of all polioviruses will depend not only on containment, but also on rapid detection and response to wild-type or vaccine-derived poliovirus outbreaks. This requires sensitive surveillance responsive to the changing nature of the risks to eradication.\nIn this paper \"Evaluation of Acute Flaccid Paralysis Surveillance indicators in Sokoto State, Nigeria, 2012-2019: A secondary data analysis\" the authors refer to AFP surveillance in Nigerian region. AFP is the corner stone to surveillance of poliovirus, because it allows for permanent vigilance of clinically compatible cases, and its translation to the scientific community is important to maintain awareness.\nThe paper is well written although there are some phrases that are somehat akward:\nAbstract\n* Line 31 Background : Nigeria and indeed, entire Africa has been certified free of Wild Polio Virus (WPV) in 2020.\nNigeria, the last endemic country in the WHO African Region was certified free of Wild Polio Virus (WPV) in 2020.\n* Line 33 states like Sokoto in Nigeria, which has an international border \nWhat significance does it have that there is international border if the entire region if certified Polio free? Is the neighboring country a high risk of importation site? I think this is not relevant unless there is a known risk of transboundary importation. As you state in the introduction there are areas in the same country that might pose a greater risk ( conflict zones like Borno state in Nigeria)\n* Line 35 Therefore,\nChange to: The aim of this study is to evaluate……\n\n* Line 45 The non-polio AFP rate (9.1 to 23.5%)\nWhat does this rate refer to? Shouldn't it be the incidence rate of AFP among children \u003c15yo? If so it should be expressed as x 100,000 \u003c15 yo population in Sokoto state. Being that the period evaluated is of several years, this value corresponds to the mean, median or overall?\n\nIntroduction :\n* Line 68 endemic countries would have led to the biggest-ever\nRephrase as a future event : will lead to …..\n\n* Line 71 To eradicate polio, every child must receive the polio vaccine.\nRephrase as: To achieve polioeradication sustained vaccine coverage must be maintained and every child must receive adequate immunization.\n\n* Line 74 The presence of just a child\nchange to The presence of just one child\n\n* Line 76 and 77 There is no need to state the same reference twice almost in the same line\n* Line 84 In countries that are not yet declared polio-free, surveillance plays a central role in the eradication process [9]. \nBut this is not the case of Nigeria, the truth is that AFP surveillance is the corner stone for polioeradication and also for the maintenance of polio free status . I suggest you rephrase the sentence in this sense or simply delete the above mentioned sentence.\n* Line 88-90 …. See comment on the same phrase in abstract\n* Line 90 the rare form of the poliovirus : Why do you qualify VDPV as a re form ?\n* Line 94 cvDPV2 should be cVDPV2\n* Line 99 … see abstract\n* Methods\nLine 143 60-day follow-up\nIsn't it for all AFP cases?\nResults\n* To what do you attribute the missing AFP diagnosis? More than 59% is much too high to discard without information. I understand that there is no causative agent identified , but the final diagnosis , be it Guillain Barrre Syndrome of Mielitis or whatsoever should be stated as AFPs . Those considered No AFP means that they did not fulfill the case definition criteria? This should be better explained in the methods section\n* AFP performance indicators refer only to those AFP cases which have been confirmed as AFP?\nIf so then the entire calculation of data ( age group distribution etc ) should be carried out referring to the 1187 AFP cases not the Number of AFP cases (n = 3001)\nDiscussion:\nLine 225 \"hot\" case has not been defined before\nLine 267 Proportion of AFP cases investigated within 48 hours of notification refers to stool collection within 48 hours ? I believe this is the indicator Proportion of AFP cases with two adequate stool specimens included in table 2 Please provide the definition of this indicator \n\nA thourough revision and corrections have to be carried out in order to make this paper suitable for publication\n\n\n\n* Publons Reviewer Recognition. Springer Nature can send verification of this review directly to Publons (a subsidiary of Clarivate Analytics). If you would like to take advantage of this service, please click on the “Yes” option below. Your name, email address, title of the reviewed manuscript, name of the journal, and date of your review submission (the “Review Data”) will then be transmitted to Publons after the final decision on the manuscript has been made. If you have already registered at Publons, they will notify you of the receipt of this review and update your profile as per your settings and their policy. If you are not registered with Publons, you will receive an email from them asking you to register in order for them to be able to recognize your review on your new profile page. Publons may use the Review Data to generate derivative metadata for the benefit of Publons and you as a reviewer, carefully considering the sensitivity of such information. For example, Publons may verify your record as a reviewer by updating your profile published on its webservice if you have registered for such service or help editors to identify candidate reviewers. Please find the details of processing in Publons’ privacy policy https://publons.com/about/terms: **Yes**\n* Declaration of competing interests: **'I declare that I have no competing interests'**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n* Is the study design appropriate to answer the research question (including the use of appropriate controls), and are the conclusions supported by the evidence presented?: **Yes**\n* Are the methods sufficiently described to allow the study to be repeated?: **No**\n* Is the use of statistics and treatment of uncertainties appropriate?: **Yes**\n* Is the presentation of the work clear?: **No**\n* Are the images in this manuscript (including electrophoretic gels and blots) free from apparent manipulation?: **Yes**\n"},{"type":"decision","content":"Major revision","date":"2021-03-07T00:00:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-12-07T00:00:00+00:00","index":2,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-11-30T00:00:00+00:00","index":1,"fulltext":"Recommendation: Major revisions required\nForm responses:\n---\n\nComments to Author:\n---\n\nThe paper while evaluating the AFP surveillance system has not added additional information to what is known about AFP surveillance in states with similar context,. Where there are differences, in expected results it has provided no clear reasons in the discussion why these differences occur. Also comparing results from Sokoto and Ghana or Zambia or Zimbabwe may be difficult as these countries had been certified WPV some years ago rather these results is best compared with other similar states in Nigeria or countries that were certified WPV around the same time as Nigeria. Also apart from 2 main indicators, it would have been interesting to analyze other data such as % of cases validated within 7 days, % of true AFP cases etc as these are important indicators to measure the entire AFP surveillance system. Look at the timeliness of samples reaching the lab as countries in lock down have shown delay in sample arrival up to even 1 month yet the virus s picked, emphasis should be on the reverse cold chain and how it is done in the state. Also many countries fly samples to labs and still have good NPENT, just to better understand the arguments that because samples are accompanied by personnel makes the system a better one?\nFinally how your conclusion that getting data managers will add value to the system is not justified as no where did you mention the data managers in the body, how data is collected , cleaned, how many personnel is involved, the paper only talked about missing variables, this could be solved by supervision or training?\nMinor issues to take note, need to ensure when stating poliovirus you state if it is the wild or circulating, while both cause paralysis, the audience need that clarity eg line 66 Nigeria has been declared Wild poliovirus free and not Nigeria declared poliovirus free, line 70 alludes to the fact that because the vaccine is cheap and effective poliovirus and many more diseases can be targeted for eradication but this is really superficial as many more reasons where considered and should be discussed in eradication of a disease. Line 97 confirm that it is eradication or interruption of cVDPV. Line 137 role of DSNO is clear but tif that of the LGA facilitator and ast DSNO is just to support or are on WHO payroll, does not add more information as I am aware other personnel/agencies support the DSNO or elaborate more on their roles.\nThe limitations and how they were addressed is missing\n\n\n\n* Publons Reviewer Recognition. Springer Nature can send verification of this review directly to Publons (a subsidiary of Clarivate Analytics). If you would like to take advantage of this service, please click on the “Yes” option below. Your name, email address, title of the reviewed manuscript, name of the journal, and date of your review submission (the “Review Data”) will then be transmitted to Publons after the final decision on the manuscript has been made. If you have already registered at Publons, they will notify you of the receipt of this review and update your profile as per your settings and their policy. If you are not registered with Publons, you will receive an email from them asking you to register in order for them to be able to recognize your review on your new profile page. Publons may use the Review Data to generate derivative metadata for the benefit of Publons and you as a reviewer, carefully considering the sensitivity of such information. For example, Publons may verify your record as a reviewer by updating your profile published on its webservice if you have registered for such service or help editors to identify candidate reviewers. Please find the details of processing in Publons’ privacy policy https://publons.com/about/terms: **Yes**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n* Is the study design appropriate to answer the research question (including the use of appropriate controls), and are the conclusions supported by the evidence presented?: **Yes**\n* Are the methods sufficiently described to allow the study to be repeated?: **Yes**\n* Is the use of statistics and treatment of uncertainties appropriate?: **Yes**\n* Is the presentation of the work clear?: **Yes**\n* Are the images in this manuscript (including electrophoretic gels and blots) free from apparent manipulation?: **Yes**\n"},{"type":"reviewersInvited","content":"","date":"2020-11-29T00:00:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-11-29T00:00:00+00:00","index":1,"fulltext":""},{"type":"editorAssigned","content":"","date":"2020-11-27T00:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2020-11-26T23:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-11-26T23:00:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"","date":"2020-10-27T00:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-public-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pubh","sideBox":"Learn more about [BMC Public Health](http://bmcpublichealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pubh/default.aspx","title":"BMC Public Health","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"22b79b18-434f-43ab-a123-1f4df08a9abf","owner":[],"postedDate":"December 3rd, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":1309843,"name":"Health Economics \u0026 Outcomes Research"},{"id":1309844,"name":"Infectious Diseases"},{"id":1309845,"name":"Health Policy"}],"tags":[],"updatedAt":"2020-12-03T17:25:11+00:00","versionOfRecord":[],"versionCreatedAt":"2020-12-03 17:25:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-117324","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-117324","identity":"rs-117324","version":["v1"]},"buildId":"FbvkV6FR0MCFSLy54lSbu","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}