Developing a reproducible quality COVID-19 RDT proficiency testing scheme: A rapid response to quality assured COVID-19 point of care testing

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To address this gap, the WHO Supranational Reference Laboratory in Kampala, Uganda, established a proficiency testing (PT) program. Methods: SARS-CoV-2 antigen PT panels were developed at the Kampala SRL and distributed to 12 sub-Saharan countries. Each round involved five blinded PT samples, provided twice annually to 764 testing sites between November 2021 and November 2024. Competency was evaluated by comparing reported results with expected outcomes, assigning percentage scores, and delivering feedback reports. Results: The PT materials demonstrated stability for up to 56 days at temperatures as high as 46°C. The average pass rate exceeded 87% across all rounds, with the highest performance reaching 95%. Participation across the 12 countries declined from 53.1% to 38.1% over three years, primarily due to reduced COVID-19 testing demand. Conclusion: This study shows that the developed SARS-CoV-2 antigen PT panels are a feasible option for external quality assessment in resource-limited settings. Strengthening quality management systems, providing refresher training, and expanding PT programs to remote facilities are critical for sustaining high-quality COVID-19 diagnostics. External quality assurance SARS-CoV-2 Antigen-RDT Quality control COVID-19 Proficiency testing Sub-Saharan Africa Figures Figure 1 Figure 9 Introduction On March 11, 2020, the World Health Organization (WHO) declared the SARS-CoV-2 outbreak a global pandemic, emphasizing the need to increase testing frequency as a key response measure. [ 1 ]. Since the emergence of COVID-19, quantitative reverse transcription polymerase chain reaction (RT-qPCR) has been regarded as the gold standard for detecting SARS-CoV-2 due to its superior sensitivity and specificity[ 2 ]. The nucleic acid amplification tests (NAAT) diagnostics of SARS-CoV-2 infections are no longer limited to reference laboratories and a few highly specialized research institutions but are offered by numerous laboratories for standard care.[ 3 ]. In the early 2021, Antigen-based lateral flow tests (LFTs) commonly known as antigen rapid diagnostic tests (Ag-RDTs) were added into testing programs to increase global access to diagnostics in numerous countries[ 4 ][ 5 ][ 6 ]. These point-of-care tests (PoCTs) are quick, relatively inexpensive, and can be operated with minimal equipment and training. The COVID-19 Ag-RDTs, detect the presence of circulating antigens, such as nucleoprotein (N) or spike (S) proteins in those who have been infected with SARS CoV-2[ 7 ]. The RDTs presents a good option for mass testing due to availability and particularly where NAAT testing capacity is limited or a quick test turnaround time is required[ 8 ][ 9 ][ 10 ]. Decentralized testing at community and primary health care levels, especially in low- and middle-income countries (LMICs), where laboratory infrastructure for RT-PCR may be limited is currently recommended due user-friendly[ 11 ]. With continual increase in commercial Ag-RDTs, there is need to check the quality of testing[ 12 ][ 13 ]. Although Ag-RDTs are simpler than complex molecular tests, quality management remains important as test accuracy and reliability is dependent not only on the assay performance characteristics, but on all aspects of testing (from sample collection to result interpretation, reporting and communication)[ 14 ]. External quality assurance (EQA) programs are a vital part of strong laboratory and health systems because they provide objective evaluation of quality services in compliance with international quality standards[ 15 ][ 16 ][ 17 ]. However, many countries especially those in sub Saharan African region do not have a means to monitor the quality of testing in these laboratories and POCTs. In 2021, the WHO Supranational Reference Laboratory in Kampala, Uganda (SRL-Kampala) was among the first institutions globally to launch an external quality assessment (EQA) program also referred to as a proficiency test (PT) for SARS-CoV-2 antigen detection. This PT scheme design was also informed by 5 years of SRL-Kampala experience as an ISO 17043:2010 accredited EQA provider. We share nearly three years (five PT rounds) of experience implementing a COVID-19 antigen EQA program to evaluate the quality of laboratories operating across sub-Saharan Africa. Methodology Materials and Methods Optimization and stability testing The proficiency testing panels were developed by SRL-Kampala, an accredited quality assurance provider under ISO 17043:2010. The Ag-RDT study samples were prepared using in-house developed protocol. Briefly, Viral Transport Medium (VTM) was used as the negative control and as diluent for commercial N-protein. The protein concentration at 2.15 mg/ml was diluted with VTM to generate working solution of 0.1 µg/ml. Aliquots were prepared by transferring 350 µl of the diluted protein into 2 ml screw-cap Sarstedt cryogenic vials. Stability testing of the newly developed SARS-CoV-2 antigen materials was carried out in the laboratory by storing the Ag-RDTs under three different conditions: refrigerated (2–8°C), ambient (18–25°C), and incubated at elevated temperatures (35–38°C and 43–47°C). Testing was carried out for up to 56 days post-production, following the manufacturers’ instructions for seven (7) commercially available RDT kits in Uganda: Panbio™ COVID-19 Ag Rapid Test (Abbott), STANDARD Q COVID-19 Ag Test (SD Biosensor), Colloidal Gold (Tianjin Biotechnology), Eco-Test (Assure Tech), Dewei (Dewei Medical), Chil (Chil Products), and Xiamen (Xiamen Boson Biotech). Before each testing interval, samples were inverted ten times and allowed to stand for one minute to ensure homogeneity. Subsequently, nine drops of each sample were aseptically transferred with a sterile Pasteur pipette into the antigen extraction buffer provided with the respective RDT kits. Pilot Study Pilot Study Fourteen (14) testing sites located around Kampala and Adjumani District were purposively selected to conduct a pilot evaluation. Antigen PT panels were freshly prepared using N-protein and labeled N1 to N5. The EQA panels, packaged as liquid samples, were distributed under ambient conditions along with instructions for processing and result submission. Recognizing that many point-of-care and peripheral sites have limited access to pipetting devices, simplified guidance was provided through a tailored job aid. Each PT package contained five vials (two positive and three negative), five individually wrapped 1 ml transfer pipettes, a results return form, and the job aid. Participants were instructed to test the materials using their routine procedures by dispensing nine drops of each sample into the assay extraction buffer and processing according to the manufacturer’s instructions or internal procedures. After completing the EQA, they recorded their findings as “positive,” “negative,” or “invalid” on the provided results form. Workflow details were also documented during submission. Reported data were compiled and analyzed in a customized Microsoft Excel spreadsheet designed for this pilot. For this initial stage, only qualitative outcomes were assessed, with overall performance determined by comparison to the EQA consensus. Each participant received an EQA report detailing their individual performance. EQA panel design and participation (dup: abstract ?) This survey was an antigen proficiency testing (PT) exercise targeting healthcare workers at health centers and point-of-care (POC) testing sites, including both rural and urban community facilities within public and private healthcare settings that conduct SARS-CoV-2 antigen rapid diagnostic tests (Ag-RDTs). Since the inception of the SARS CoV-2 proficiency testing (PT) scheme in 2021, five external quality assessment (EQA) rounds have been organized and distributed to twelve countries across sub-Saharan Africa, as outlined in Table 1 . The participating countries included Uganda, Kenya, Tanzania, Seychelles, Mauritius, Zambia, Malawi, Mozambique, Namibia, Eswatini, Angola, and Lesotho Fig. 1 illustrates the geographical distribution of the participating countries in this initiative. Each round package included distinct five vials of sets of panels, five individually wrapped 1 ml transfer pipettes, a result submission form, and a simple job aid. Country coordinators were tasked with distributing the panels to participating testing sites and facilitating the submission of results through the online reporting platform ( https://srlugpt.com/ ) within twelve weeks of panel shipment. An adequate number of PT panels were supplied to participating countries to ensure each enrolled site received one complete pack. Table 1 Number of participants from 12 countries across sub-Sahara Africa from 2022–2024 Country PT Round number Round one 2022 Round one 2023 Round two 2023 Round one 2024 Round two 2024 Angola 1 1 1 1 - Eswatini 20 28 28 28 25 Kenya 181 97 107 107 - Lesotho 156 141 210 210 50 Malawi 25 17 17 17 10 Mauritius 16 14 14 14 10 Mozambique 20 23 20 20 17 Namibia 28 24 10 12 2 Seychelles 3 3 19 20 10 Tanzania 131 119 102 102 - Uganda 1 1 65 65 14 Zambia 156 151 171 171 64 Total enrolled 738 619 765 764 202 Table 1 shows the number of laboratories enrolled in Proficiency Testing (PT) rounds from 2022 to 2024 across 12 countries. Each column represents a specific PT round, and the figures indicate the number of enrolled labs per country. Some countries, like Kenya and Zambia, had high participation across all rounds, while others, like Angola and Uganda, had fewer labs enrolled. The total row shows overall participation per round, with the highest in Round 2 of 2023 (765 labs) and the lowest in Round 2 of 2024 (202 labs) Panel evaluation and scoring Participant results and feedback were submitted through the online reporting platform ( https://srlugpt.com/ ) and analyzed by the PT provider (SRL-Kampala). For each site, an individualized report was generated, comparing submitted results with the expected outcomes validated by the provider. The reports also included consensus findings aggregated from all participating sites across countries. Consensus for each PT sample was defined as at least 80% agreement between participant results and the expected outcome. Overall performance was evaluated using a scoring system based on qualitative classifications (Positive, Negative, or Invalid). Sites received a score of 20 points for acceptable performance and 0 points where discrepancies were observed. At the test unit level, scores were expressed as the percentage of correctly identified samples, meaning negative aliquots tested negative and positive aliquots tested positive. For this analysis, a minimum threshold of 80% correct results was set to define acceptable proficiency. RESULTS Optimization and stability testing At each time point, both positive and negative panel samples were evaluated using all test kits under controlled temperature conditions. Throughout the 56-day study period, all kits demonstrated consistent performance, yielding expected results across all temperature ranges, including elevated conditions (35–38°C and 43–47°C). No false positives or false negatives were observed, indicating strong thermal resilience of the developed PT materials. As detailed in Table 2 , PT materials maintained analytical integrity under all tested conditions, affirming their thermal stability suggesting good robustness for field conditions Table 2 Stability Summary of SARS-CoV-2 antigen PT materials on various Rapid Diagnostic Test Kits from 0–56 Days Test Kit Manufacturer 2–8°C Room Temp (18–25°C) 35–38°C 43–47°C Up to 56 Days Stability Panbio Abbott Stable Stable Stable Stable Stable STANDARD Q SD Biosensor Stable Stable Stable Stable Stable Colloidal Tianjin Biotechnology Stable Stable Stable Stable Stable Eco-test Assure Tech Stable Stable Stable Stable Stable Dewei Dewei Medical Stable Stable Stable Stable Stable Chil Chil Products Stable Stable Stable Stable Stable Xiamen Xiamen Boson Biotech Stable Stable Stable Stable Stable *Legend: Stable = Expected positive and negative results consistently observed. Pilot Study Proficiency testing performance across 13 testing sites using Panbio™ (Abbott)-6 sites and STANDARD Q (SD Biosensor)-6 sites, antigen kits. Sites were evaluated against five expected SARS-CoV-2 antigen results. One site (Site 02) using Panbio™ recorded a low score (40%) due to misidentification of negative samples. All other sites correctly identified all samples. Data received from these laboratories demonstrated relative closeness of validation results Table 3 Proficiency testing outcomes from 13 pilot sites in Uganda Antigen Kit Used Number of Sites Mean Score (%) Sites with 100% Sites with < 100% Panbio™ (Abbott) 6 90 5 1 STANDARD Q (SD Biosensor) 6 100 6 0 Not provided 1 100 1 0 *Panbio™ COVID-19 Ag Rapid Test Device (Abbott, Jena, Germany) *STANDARD Q COVID-19 Ag Test (SD Biosensor, Inc., Suwon-si, Gyeonggi-do, Republic of Korea) EQA panel design and participation Table 4 summarizes site performance across five proficiency testing (PT) rounds from 2022 to 2024. Each row shows the number of sites enrolled and those that submitted results, the number and percentage that passed, and error rates (false negatives, false positives, and invalid results). Pass rates ranged from 87.4% to 95%, indicating generally good performance. False negatives were consistently low (0.6%–3.4%), while false positives varied more, peaking at 13.1% in Round 1 2024. Invalid results were rare, suggesting good procedural quality. However, low participation rates in all rounds were noted and require attention Table 4 Number and percentage of sites participating and achieving passing scores in Ag-SARS CoV-2 proficiency testing programme for participating countries, 2022–2024. Round Number No. participated/ No. enrolled No. passed/No participates % False Negative (%) False Positive (%) Invalid % Round 1 2022 439/738 (385/439) 87.7 3.2 8.2 0.87 Round 1 2023 358/619 333/358 93 1.0 5.7 0.3 Round 2 2023 406/765 355/406 87.4 3.4 9.2 0.1 Round 1 2024 204/764 197/204 87.7 0.6 13.1 0.0 Round 2 2024 77/202 73/77 95 1.5 3.5 0.0 DISCUSSION The programme described in this paper utilized antigen materials to assess health worker competency, through a PT programme, for performing SARS CoV-2 rapid diagnostic tests. The use of PTs for rapid testing in this setting allowed for the successful evaluation of testers with varying levels of education at peripheral health facilities where robust QMS may not be in place. We have shown that it is feasible to implement an Ag-SARs CoV-2 proficiency testing program programme for low and middle income countries using materials available in most reference laboratories. Over the five rounds of PT panels provided across a period of three years, the number of countries participating in the programme remained constant see Table 1 . Viral Transport Medium (VTM) was used in this PT panel production to mimic the COVID 19 samples and also medium is specifically designed to preserve viral RNA or whole viruses during transportation and storage. This was critical for EQA panels where the integrity of the sample must remain intact from the central distribution point to the testing laboratories, sometimes across long distances and varying temperatures[ 18 ]. In this PT panel we put a concentration of 0.1 mg/ml to target middle ground. However, most Ag-RDTs are designed to detect high viral loads typical during the infectious phase (usually within the first 5–7 days of symptoms). The limit of detection ranges between 50 to 10,000 TCID₅₀/mL [ 19 ]. This study demonstrated that all developed PT materials maintained stability and accuracy across a range of temperatures and storage durations, including high-temperature conditions up to 46°C for 56 days as illustrated in Table 2 . The consistent performance across elevated temperatures suggests that these materials are suitable for use in resource-limited and high-temperature field settings where cold-chain logistics may be unavailable. This has important implications for decentralized testing programs in Sub-Sahara regions. As observed in Table 4 , the proficiency testing (PT) data across five rounds (2022–2024) reveals consistent trends in both participation and performance among enrolled laboratories. While participation rates varied across rounds, with the lowest in Round 2 of 2024 (38.1%) and the highest in Round 2 of 2023 (53.1%), pass rates generally remained high, reflecting adequate diagnostic capacity among the testing sites. The average pass rate across all rounds was above 87%, peaking at 95% in Round 2 of 2024. This suggests that the majority of participating laboratories were able to produce acceptable results, indicating good adherence to quality standards. However, the proportion of false positives was notably higher in some rounds, particularly Round 1 of 2024, which recorded a 13.1% false positive rate, the highest across all rounds. Such elevated false positive rates may point to procedural errors, operator training and experience strongly influence result interpretation including lack of adherence to the manufacturer’s instruction including misreading or misinterpretation of results by health workers, incorrect interpretation of faint test lines, contamination, or poor adherence to manufacturer instructions[ 20 ][ 21 ]. The observed false positive more frequent results which may be due to cross-reactivity with other viruses, poor kit quality or environmental factors and misinterpretation of faint lines[ 4 ]. False negatives remained relatively low across the board, ranging from 0.6% to 3.4%, which is critical from a public health standpoint, as it minimizes missed COVID-19 cases. Invalid result rates were negligible, indicating appropriate test handling and kit performance. The observed variations in performance metrics between rounds may also reflect differences in test kit types used, staff training levels, and logistical challenges affecting timely panel delivery and proper storage, all of which can impact test accuracy. While health workers who conduct diagnostic testing in the laboratory or at the point-of-care strive to operate under a well-functioning Quality Management System (QMS), such systems are not always in place. The QMS consists of structured procedures and activities designed to ensure that the testing process produces accurate and reliable results to support proper patient care. The use of QC material for SARS CoV-2 rapid testing, as a part of QMS, can be used to ascertain competency for testing. The novel approach described here provides a simple solution for implementing PT programs in most Ag SARS CoV-2 testing sites. The same strategy could also be used to prepare quality control specimens that can be distributed to the COVID 19 testing sites. This study provides valuable insights into the scale and continuity of laboratory quality assurance efforts in the region. Countries with consistent and increasing participation are likely prioritizing laboratory strengthening and diagnostic accuracy. The data can also help identify countries where additional support or engagement may be needed to ensure widespread and sustained participation in PT activities Challenges and limitations Several challenges were encountered during the implementation of the PT programme. One major issue involved logistical constraints, particularly delays in distributing panels. Shipping PT panels across international borders or to remote locations was often hampered by customs clearance processes, unreliable country’s courier services, and poor transport infrastructure. The financial limitations also affected participation, as inadequate funding for panel production, shipment, and participation fees restricted full engagement from all intended countries and testing sites. Although the programme initially aimed to reach 2,000 sites from 12 countries, only 800 were successfully covered due to these constraints. A decline in participation was also noted due to site withdrawal, particularly among private or low-volume facilities. These sites often perceived limited benefit from the programme or considered it an added burden to their existing workload. Another key limitation was the lack of effective follow-up on poor performance, largely due to weak supervisory mechanisms. In many cases, issues identified during the PT rounds were not addressed with appropriate on-site support, follow-up training, or corrective action, leading to repeated errors. Despite the availability of an online reporting system ( https://srlugpt.com/ ) to submit results and feedback, delays in data entry were common. Late submissions and a high volume of incomplete or inaccurately submitted results hindered timely evaluation and limited the programme’s ability to generate accurate, actionable insights. CONCLUSIONS A continuous quality improvement package for SARS CoV-2 in in Sub-Sahara that includes routine distribution of PT material is an important contributor to ensuring provision of accurate results. The antigen-based PT program proved effective for assessing and supporting SARS-CoV-2 testing quality in low-resource settings. Its design allowed for deployment in decentralized locations, including those without advanced laboratory infrastructure or cold-chain systems. The sustained performance of PT materials under adverse storage conditions further supports its applicability in high-temperature field environments. High pass rates across diverse testing sites affirm that frontline health workers can perform rapid diagnostic tests accurately, provided they receive appropriate training and oversight. However, the recurrent false positives highlight the need for better training, particularly in result interpretation, and stricter adherence to test protocols. The model demonstrated in this study offers a cost-effective and scalable approach to external quality assessment in LMICs, with potential applicability beyond SARS-CoV-2. Future efforts should focus on increasing site coverage, improving digital result reporting, and integrating corrective action plans into national laboratory systems to ensure sustainability and continuous improvement in diagnostic quality ETHICS APPROVAL Ethical permission and approval to conduct this study was sought from National Health Laboratory Diagnostic Services. All methods used in this study were performed in accordance with the relevant guidelines and regulations. Administrative clearance was obtained from National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory, Kampala, Uganda. It is worth noting that all enrolled sites were required to complete a Confidentiality Waiver and Participant Biosafety Compliance Letter Agreement before participation. Declarations ETHICS APPROVAL Ethical permission and approval to conduct this study was sought from National Health Laboratory Diagnostic Services. All methods used in this study were performed in accordance with the relevant guidelines and regulations. Administrative clearance was obtained from National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory, Kampala, Uganda. It is worth noting that all enrolled sites were required to complete a Confidentiality Waiver and Participant Biosafety Compliance Letter Agreement before participation. Consent for publication Not applicable Availability of data and materials All relevant data are within the paper and its Supporting Information files. Competing of Interest None to declare Funding The author(s) received no special funding for this work. The financial support to run all the above activities was part of the COVID-19 Response Mechanism (C19RM) regional Global fund through the East, Central and Southern Africa (ECSA) Health Community Project to the Supra-National Reference Laboratory of Uganda Authors’ contributions: HNS PL IA JMK and KM: Contributed to the conception of the study; HNS PL IA JMK JN KM and MLJ: Contributed to the design of the work; HNS PL IA JMK WI KM PU: Contributed to the acquisition and analysis of data; HNS PL IA JMK JN KM PU KF and MLJ: Contributed to the interpretation of data; HNS PL IA JMK JN KM PU KF and MLJ: Drafted the work and substantively revised it; HNS PL IA JMK JN KM PU WI KF and MLJ: Approved the submitted version; HNS PL IA JMK JN KM PU WI KF and MLJ: Agreed both to be personally accountable for the author's own contributions and to ensure that questions related to the accuracy or integrity of any part of the work, even ones in which the author was not personally involved, appropriately investigated, resolved, and the resolution documented in the literature. Acknowledgements We express our sincere appreciation to all the participants who took part in this proficiency testing (PT) initiative, as well as the dedicated team at the Supra-National Reference Laboratory of Uganda for their technical expertise and administrative contributions. We also gratefully acknowledge the valuable training and guidance provided by Kyle DeGruy and Patricia Hall from the Division of Global HIV and TB, International Laboratory Branch, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA. Additionally, we recognize the support of the Regional Global Fund through the East, Central, and Southern Africa (ECSA) Health Community Project. References World Health Organization (WHO). WHO Director-General’s opening remarks at the media briefing on COVID-19–11 March 2020, 2020. https://www.who.int/director-general/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020 (accessed Mar. 08, 2024). 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FIND, FIND evaluations of SARS-CoV-2 Ag tests - FIND., 2023. https://www.finddx.org/covid-19/find-evaluations-of-sars-cov-2-assays/find-evaluations-of-sars-cov-2-ag-tests/ (accessed Aug. 24, 2025). World Health Organization (WHO). Antigen-detection in the diagnosis of SARS-CoV-2 infection Interim guidance, 2021. World Health Organization (WHO). SARS-CoV-2 antigen-detecting rapid diagnostic tests, 2021. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. 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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-8568737","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":574464563,"identity":"33b83861-06d4-4037-b254-6527a6499b02","order_by":0,"name":"Hasifah Ssentamu Nakato","email":"","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Hasifah","middleName":"Ssentamu","lastName":"Nakato","suffix":""},{"id":574464564,"identity":"ef85832c-1df2-483d-9def-f9e5d6df183e","order_by":1,"name":"Pius Lutaaya","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3ElEQVRIiWNgGAWjYBACAxjJ2Mx8AMiSkCFeC3N7WwJICw+RWoCAvecMmE1Yizl778HHBQWH7Xln5Hx+daPGgoeB/fDRDfi0WPacSzaeYXA4ceaM3G3WOceADuNJS7uB12E3csykeQwOJxgCtRjnsAG1SPCYEdJi/huoxd7+Rs4z45x/xGkxYwZqYWzsOcP8OLeNGC1nziVLzzBIT2xsbzNjzu2T4GEj6JfjvQc/F/yxtgdG5ePPOd/q5PjZDx/DqwUUEcxQFpsEmMSvHFUL8wfCqkfBKBgFo2AkAgBBSUf0Wc6yIQAAAABJRU5ErkJggg==","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":true,"prefix":"","firstName":"Pius","middleName":"","lastName":"Lutaaya","suffix":""},{"id":574464566,"identity":"70d66828-ccb8-4099-ba67-960d865aac58","order_by":2,"name":"Isa Adam","email":"","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Isa","middleName":"","lastName":"Adam","suffix":""},{"id":574464567,"identity":"cc7636e3-25a0-4ad1-8286-c41e65819337","order_by":3,"name":"Jupiter Marina Kabahita","email":"","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Jupiter","middleName":"Marina","lastName":"Kabahita","suffix":""},{"id":574464568,"identity":"9c7d0d53-0cd8-4c35-872d-f0c8d25cafc3","order_by":4,"name":"Joanita Namutebi","email":"","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Joanita","middleName":"","lastName":"Namutebi","suffix":""},{"id":574464569,"identity":"46bdfb56-a051-4198-b910-8fce2ab68e2a","order_by":5,"name":"Kenneth Musisi","email":"","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Kenneth","middleName":"","lastName":"Musisi","suffix":""},{"id":574464570,"identity":"77054fa5-533f-49cc-baea-96585449cfee","order_by":6,"name":"Ivan Wabwire","email":"","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Ivan","middleName":"","lastName":"Wabwire","suffix":""},{"id":574464571,"identity":"c1f73180-dd7b-4eb3-8276-a821ed37934f","order_by":7,"name":"Fredrick Kangave","email":"","orcid":"","institution":"National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory","correspondingAuthor":false,"prefix":"","firstName":"Fredrick","middleName":"","lastName":"Kangave","suffix":""},{"id":574464572,"identity":"b3cae9cf-6c86-4661-ba50-903a6705a8a8","order_by":8,"name":"Paula Uwimbabazi","email":"","orcid":"","institution":"National Tuberculosis Reference 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08:04:58","extension":"xml","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":96365,"visible":true,"origin":"","legend":"","description":"","filename":"4f0a2f441a97413ea8f4e779e753fc5a1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8568737/v1/ffe22e1b7ca509e508a9b714.xml"},{"id":100546522,"identity":"d7701064-c7a4-4cfc-b9aa-946f265e97b2","added_by":"auto","created_at":"2026-01-19 08:10:15","extension":"html","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":106144,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8568737/v1/1226cdfb25f5d8398209b8e2.html"},{"id":100546494,"identity":"f6ee6662-ee6d-4383-b1e3-eddb5b47434e","added_by":"auto","created_at":"2026-01-19 08:09:54","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":248330,"visible":true,"origin":"","legend":"\u003cp\u003eA map of Africa showing distribution of countries participating (red stars) in the SRL Kampala (green star) antigen-RDT proficiency Testing scheme\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8568737/v1/d09caded66a8c2fc3b1d40aa.jpeg"},{"id":100546306,"identity":"492cb3c7-f4b9-4672-8667-cdd36d4189d8","added_by":"auto","created_at":"2026-01-19 08:05:23","extension":"jpeg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":248330,"visible":true,"origin":"","legend":"\u003cp\u003eA map of Africa showing distribution of countries participating (red stars) in the SRL Kampala (green star) antigen-RDT proficiency Testing scheme\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8568737/v1/e0acf6b0e8c94a2780c22fd4.jpeg"},{"id":105033594,"identity":"fac75290-b280-469d-a1cb-91b07e41f489","added_by":"auto","created_at":"2026-03-20 07:20:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1361388,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8568737/v1/0322a841-4a42-4667-a1b9-8a9c12d456ff.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Developing a reproducible quality COVID-19 RDT proficiency testing scheme: A rapid response to quality assured COVID-19 point of care testing","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOn March 11, 2020, the World Health Organization (WHO) declared the SARS-CoV-2 outbreak a global pandemic, emphasizing the need to increase testing frequency as a key response measure. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Since the emergence of COVID-19, quantitative reverse transcription polymerase chain reaction (RT-qPCR) has been regarded as the gold standard for detecting SARS-CoV-2 due to its superior sensitivity and specificity[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The nucleic acid amplification tests (NAAT) diagnostics of SARS-CoV-2 infections are no longer limited to reference laboratories and a few highly specialized research institutions but are offered by numerous laboratories for standard care.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn the early 2021, Antigen-based lateral flow tests (LFTs) commonly known as antigen rapid diagnostic tests (Ag-RDTs) were added into testing programs to increase global access to diagnostics in numerous countries[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e][\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e][\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. These point-of-care tests (PoCTs) are quick, relatively inexpensive, and can be operated with minimal equipment and training. The COVID-19 Ag-RDTs, detect the presence of circulating antigens, such as nucleoprotein (N) or spike (S) proteins in those who have been infected with SARS CoV-2[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The RDTs presents a good option for mass testing due to availability and particularly where NAAT testing capacity is limited or a quick test turnaround time is required[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e][\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e][\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Decentralized testing at community and primary health care levels, especially in low- and middle-income countries (LMICs), where laboratory infrastructure for RT-PCR may be limited is currently recommended due user-friendly[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. With continual increase in commercial Ag-RDTs, there is need to check the quality of testing[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e][\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlthough Ag-RDTs are simpler than complex molecular tests, quality management remains important as test accuracy and reliability is dependent not only on the assay performance characteristics, but on all aspects of testing (from sample collection to result interpretation, reporting and communication)[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. External quality assurance (EQA) programs are a vital part of strong laboratory and health systems because they provide objective evaluation of quality services in compliance with international quality standards[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e][\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e][\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. However, many countries especially those in sub Saharan African region do not have a means to monitor the quality of testing in these laboratories and POCTs.\u003c/p\u003e \u003cp\u003eIn 2021, the WHO Supranational Reference Laboratory in Kampala, Uganda (SRL-Kampala) was among the first institutions globally to launch an external quality assessment (EQA) program also referred to as a proficiency test (PT) for SARS-CoV-2 antigen detection. This PT scheme design was also informed by 5 years of SRL-Kampala experience as an ISO 17043:2010 accredited EQA provider. We share nearly three years (five PT rounds) of experience implementing a COVID-19 antigen EQA program to evaluate the quality of laboratories operating across sub-Saharan Africa.\u003c/p\u003e"},{"header":"Methodology Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eOptimization and stability testing\u003c/h2\u003e \u003cp\u003eThe proficiency testing panels were developed by SRL-Kampala, an accredited quality assurance provider under ISO 17043:2010. The Ag-RDT study samples were prepared using in-house developed protocol. Briefly, Viral Transport Medium (VTM) was used as the negative control and as diluent for commercial N-protein. The protein concentration at 2.15 mg/ml was diluted with VTM to generate working solution of 0.1 \u0026micro;g/ml. Aliquots were prepared by transferring 350 \u0026micro;l of the diluted protein into 2 ml screw-cap Sarstedt cryogenic vials.\u003c/p\u003e \u003cp\u003eStability testing of the newly developed SARS-CoV-2 antigen materials was carried out in the laboratory by storing the Ag-RDTs under three different conditions: refrigerated (2\u0026ndash;8\u0026deg;C), ambient (18\u0026ndash;25\u0026deg;C), and incubated at elevated temperatures (35\u0026ndash;38\u0026deg;C and 43\u0026ndash;47\u0026deg;C). Testing was carried out for up to 56 days post-production, following the manufacturers\u0026rsquo; instructions for seven (7) commercially available RDT kits in Uganda: Panbio\u0026trade; COVID-19 Ag Rapid Test (Abbott), STANDARD Q COVID-19 Ag Test (SD Biosensor), Colloidal Gold (Tianjin Biotechnology), Eco-Test (Assure Tech), Dewei (Dewei Medical), Chil (Chil Products), and Xiamen (Xiamen Boson Biotech). Before each testing interval, samples were inverted ten times and allowed to stand for one minute to ensure homogeneity. Subsequently, nine drops of each sample were aseptically transferred with a sterile Pasteur pipette into the antigen extraction buffer provided with the respective RDT kits.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePilot Study\u003c/h3\u003e\n\u003cdiv class=\"Heading\"\u003ePilot Study\u003c/div\u003e \u003cp\u003eFourteen (14) testing sites located around Kampala and Adjumani District were purposively selected to conduct a pilot evaluation. Antigen PT panels were freshly prepared using N-protein and labeled N1 to N5. The EQA panels, packaged as liquid samples, were distributed under ambient conditions along with instructions for processing and result submission. Recognizing that many point-of-care and peripheral sites have limited access to pipetting devices, simplified guidance was provided through a tailored job aid. Each PT package contained five vials (two positive and three negative), five individually wrapped 1 ml transfer pipettes, a results return form, and the job aid.\u003c/p\u003e \u003cp\u003eParticipants were instructed to test the materials using their routine procedures by dispensing nine drops of each sample into the assay extraction buffer and processing according to the manufacturer\u0026rsquo;s instructions or internal procedures. After completing the EQA, they recorded their findings as \u0026ldquo;positive,\u0026rdquo; \u0026ldquo;negative,\u0026rdquo; or \u0026ldquo;invalid\u0026rdquo; on the provided results form. Workflow details were also documented during submission. Reported data were compiled and analyzed in a customized Microsoft Excel spreadsheet designed for this pilot. For this initial stage, only qualitative outcomes were assessed, with overall performance determined by comparison to the EQA consensus. Each participant received an EQA report detailing their individual performance.\u003c/p\u003e\n\u003ch3\u003eEQA panel design and participation (dup: abstract ?)\u003c/h3\u003e\n\u003cp\u003eThis survey was an antigen proficiency testing (PT) exercise targeting healthcare workers at health centers and point-of-care (POC) testing sites, including both rural and urban community facilities within public and private healthcare settings that conduct SARS-CoV-2 antigen rapid diagnostic tests (Ag-RDTs). Since the inception of the SARS CoV-2 proficiency testing (PT) scheme in 2021, five external quality assessment (EQA) rounds have been organized and distributed to twelve countries across sub-Saharan Africa, as outlined in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The participating countries included Uganda, Kenya, Tanzania, Seychelles, Mauritius, Zambia, Malawi, Mozambique, Namibia, Eswatini, Angola, and Lesotho Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the geographical distribution of the participating countries in this initiative. Each round package included distinct five vials of sets of panels, five individually wrapped 1 ml transfer pipettes, a result submission form, and a simple job aid. Country coordinators were tasked with distributing the panels to participating testing sites and facilitating the submission of results through the online reporting platform (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://srlugpt.com/\u003c/span\u003e\u003cspan address=\"https://srlugpt.com/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e) within twelve weeks of panel shipment. An adequate number of PT panels were supplied to participating countries to ensure each enrolled site received one complete pack.\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\u003eNumber of participants from 12 countries across sub-Sahara Africa from 2022\u0026ndash;2024\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCountry\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003ePT Round number\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRound one 2022\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRound one 2023\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRound two 2023\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRound one 2024\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eRound two 2024\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAngola\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEswatini\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKenya\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e181\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e107\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLesotho\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e141\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e210\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e210\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMalawi\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMauritius\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMozambique\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNamibia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSeychelles\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTanzania\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e131\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e119\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e102\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e102\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUganda\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eZambia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e156\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e151\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e171\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e171\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e64\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal enrolled\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e738\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e619\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e765\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e764\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e202\u003c/b\u003e\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\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the number of laboratories enrolled in Proficiency Testing (PT) rounds from 2022 to 2024 across 12 countries. Each column represents a specific PT round, and the figures indicate the number of enrolled labs per country. Some countries, like Kenya and Zambia, had high participation across all rounds, while others, like Angola and Uganda, had fewer labs enrolled. The total row shows overall participation per round, with the highest in Round 2 of 2023 (765 labs) and the lowest in Round 2 of 2024 (202 labs)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003ePanel evaluation and scoring\u003c/h3\u003e\n\u003cp\u003eParticipant results and feedback were submitted through the online reporting platform (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://srlugpt.com/\u003c/span\u003e\u003cspan address=\"https://srlugpt.com/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e) and analyzed by the PT provider (SRL-Kampala). For each site, an individualized report was generated, comparing submitted results with the expected outcomes validated by the provider. The reports also included consensus findings aggregated from all participating sites across countries. Consensus for each PT sample was defined as at least 80% agreement between participant results and the expected outcome.\u003c/p\u003e \u003cp\u003eOverall performance was evaluated using a scoring system based on qualitative classifications (Positive, Negative, or Invalid). Sites received a score of 20 points for acceptable performance and 0 points where discrepancies were observed. At the test unit level, scores were expressed as the percentage of correctly identified samples, meaning negative aliquots tested negative and positive aliquots tested positive. For this analysis, a minimum threshold of 80% correct results was set to define acceptable proficiency.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eOptimization and stability testing\u003c/h2\u003e \u003cp\u003eAt each time point, both positive and negative panel samples were evaluated using all test kits under controlled temperature conditions. Throughout the 56-day study period, all kits demonstrated consistent performance, yielding expected results across all temperature ranges, including elevated conditions (35\u0026ndash;38\u0026deg;C and 43\u0026ndash;47\u0026deg;C). No false positives or false negatives were observed, indicating strong thermal resilience of the developed PT materials. As detailed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, PT materials maintained analytical integrity under all tested conditions, affirming their thermal stability suggesting good robustness for field conditions\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\u003eStability Summary of SARS-CoV-2 antigen PT materials on various Rapid Diagnostic Test Kits from 0\u0026ndash;56 Days\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTest Kit\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eManufacturer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u0026ndash;8\u0026deg;C\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRoom Temp (18\u0026ndash;25\u0026deg;C)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e35\u0026ndash;38\u0026deg;C\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e43\u0026ndash;47\u0026deg;C\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eUp to 56 Days Stability\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePanbio\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAbbott\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSTANDARD Q\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSD Biosensor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColloidal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTianjin Biotechnology\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEco-test\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssure Tech\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDewei\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDewei Medical\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChil\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eChil Products\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eXiamen\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eXiamen Boson Biotech\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eStable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eStable\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*Legend: Stable\u0026thinsp;=\u0026thinsp;Expected positive and negative results consistently observed.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePilot Study\u003c/h3\u003e\n\u003cp\u003eProficiency testing performance across 13 testing sites using Panbio\u0026trade; (Abbott)-6 sites and STANDARD Q (SD Biosensor)-6 sites, antigen kits. Sites were evaluated against five expected SARS-CoV-2 antigen results. One site (Site 02) using Panbio\u0026trade; recorded a low score (40%) due to misidentification of negative samples. All other sites correctly identified all samples. Data received from these laboratories demonstrated relative closeness of validation results\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eProficiency testing outcomes from 13 pilot sites in Uganda\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAntigen Kit Used\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of Sites\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMean Score (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSites with 100%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSites with \u0026lt;\u0026thinsp;100%\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePanbio\u0026trade; (Abbott)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSTANDARD Q (SD Biosensor)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNot provided\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*Panbio\u0026trade; COVID-19 Ag Rapid Test Device (Abbott, Jena, Germany)\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*STANDARD Q COVID-19 Ag Test (SD Biosensor, Inc., Suwon-si, Gyeonggi-do, Republic of Korea)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eEQA panel design and participation\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e summarizes site performance across five proficiency testing (PT) rounds from 2022 to 2024. Each row shows the number of sites enrolled and those that submitted results, the number and percentage that passed, and error rates (false negatives, false positives, and invalid results). Pass rates ranged from 87.4% to 95%, indicating generally good performance. False negatives were consistently low (0.6%\u0026ndash;3.4%), while false positives varied more, peaking at 13.1% in Round 1 2024. Invalid results were rare, suggesting good procedural quality. However, low participation rates in all rounds were noted and require attention\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eNumber and percentage of sites participating and achieving passing scores in Ag-SARS CoV-2 proficiency testing programme for participating countries, 2022\u0026ndash;2024.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRound Number\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo. participated/ No. enrolled\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNo. passed/No participates\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFalse Negative (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFalse Positive (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eInvalid %\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRound 1 2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e439/738\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(385/439)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e87.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e8.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.87\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRound 1 2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e358/619\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e333/358\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e5.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRound 2 2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e406/765\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e355/406\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e87.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRound 1 2024\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e204/764\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e197/204\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e87.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRound 2 2024\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77/202\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e73/77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.0\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\u003eThe programme described in this paper utilized antigen materials to assess health worker competency, through a PT programme, for performing SARS CoV-2 rapid diagnostic tests. The use of PTs for rapid testing in this setting allowed for the successful evaluation of testers with varying levels of education at peripheral health facilities where robust QMS may not be in place. We have shown that it is feasible to implement an Ag-SARs CoV-2 proficiency testing program programme for low and middle income countries using materials available in most reference laboratories. Over the five rounds of PT panels provided across a period of three years, the number of countries participating in the programme remained constant see Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eViral Transport Medium (VTM) was used in this PT panel production to mimic the COVID 19 samples and also medium is specifically designed to preserve viral RNA or whole viruses during transportation and storage. This was critical for EQA panels where the integrity of the sample must remain intact from the central distribution point to the testing laboratories, sometimes across long distances and varying temperatures[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In this PT panel we put a concentration of 0.1 mg/ml to target middle ground. However, most Ag-RDTs are designed to detect high viral loads typical during the infectious phase (usually within the first 5\u0026ndash;7 days of symptoms). The limit of detection ranges between 50 to 10,000 TCID₅₀/mL [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study demonstrated that all developed PT materials maintained stability and accuracy across a range of temperatures and storage durations, including high-temperature conditions up to 46\u0026deg;C for 56 days as illustrated in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The consistent performance across elevated temperatures suggests that these materials are suitable for use in resource-limited and high-temperature field settings where cold-chain logistics may be unavailable. This has important implications for decentralized testing programs in Sub-Sahara regions. As observed in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, the proficiency testing (PT) data across five rounds (2022\u0026ndash;2024) reveals consistent trends in both participation and performance among enrolled laboratories. While participation rates varied across rounds, with the lowest in Round 2 of 2024 (38.1%) and the highest in Round 2 of 2023 (53.1%), pass rates generally remained high, reflecting adequate diagnostic capacity among the testing sites. The average pass rate across all rounds was above 87%, peaking at 95% in Round 2 of 2024.\u003c/p\u003e \u003cp\u003eThis suggests that the majority of participating laboratories were able to produce acceptable results, indicating good adherence to quality standards. However, the proportion of false positives was notably higher in some rounds, particularly Round 1 of 2024, which recorded a 13.1% false positive rate, the highest across all rounds. Such elevated false positive rates may point to procedural errors, operator training and experience strongly influence result interpretation including lack of adherence to the manufacturer\u0026rsquo;s instruction including misreading or misinterpretation of results by health workers, incorrect interpretation of faint test lines, contamination, or poor adherence to manufacturer instructions[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e][\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The observed false positive more frequent results which may be due to cross-reactivity with other viruses, poor kit quality or environmental factors and misinterpretation of faint lines[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFalse negatives remained relatively low across the board, ranging from 0.6% to 3.4%, which is critical from a public health standpoint, as it minimizes missed COVID-19 cases. Invalid result rates were negligible, indicating appropriate test handling and kit performance. The observed variations in performance metrics between rounds may also reflect differences in test kit types used, staff training levels, and logistical challenges affecting timely panel delivery and proper storage, all of which can impact test accuracy.\u003c/p\u003e \u003cp\u003eWhile health workers who conduct diagnostic testing in the laboratory or at the point-of-care strive to operate under a well-functioning Quality Management System (QMS), such systems are not always in place. The QMS consists of structured procedures and activities designed to ensure that the testing process produces accurate and reliable results to support proper patient care. The use of QC material for SARS CoV-2 rapid testing, as a part of QMS, can be used to ascertain competency for testing. The novel approach described here provides a simple solution for implementing PT programs in most Ag SARS CoV-2 testing sites. The same strategy could also be used to prepare quality control specimens that can be distributed to the COVID 19 testing sites. This study provides valuable insights into the scale and continuity of laboratory quality assurance efforts in the region. Countries with consistent and increasing participation are likely prioritizing laboratory strengthening and diagnostic accuracy. The data can also help identify countries where additional support or engagement may be needed to ensure widespread and sustained participation in PT activities\u003c/p\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eChallenges and limitations\u003c/h2\u003e \u003cp\u003eSeveral challenges were encountered during the implementation of the PT programme. One major issue involved logistical constraints, particularly delays in distributing panels. Shipping PT panels across international borders or to remote locations was often hampered by customs clearance processes, unreliable country\u0026rsquo;s courier services, and poor transport infrastructure. The financial limitations also affected participation, as inadequate funding for panel production, shipment, and participation fees restricted full engagement from all intended countries and testing sites. Although the programme initially aimed to reach 2,000 sites from 12 countries, only 800 were successfully covered due to these constraints.\u003c/p\u003e \u003cp\u003eA decline in participation was also noted due to site withdrawal, particularly among private or low-volume facilities. These sites often perceived limited benefit from the programme or considered it an added burden to their existing workload. Another key limitation was the lack of effective follow-up on poor performance, largely due to weak supervisory mechanisms. In many cases, issues identified during the PT rounds were not addressed with appropriate on-site support, follow-up training, or corrective action, leading to repeated errors. Despite the availability of an online reporting system (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://srlugpt.com/\u003c/span\u003e\u003cspan address=\"https://srlugpt.com/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e to submit results and feedback, delays in data entry were common. Late submissions and a high volume of incomplete or inaccurately submitted results hindered timely evaluation and limited the programme\u0026rsquo;s ability to generate accurate, actionable insights.\u003c/p\u003e \u003c/div\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eA continuous quality improvement package for SARS CoV-2 in in Sub-Sahara that includes routine distribution of PT material is an important contributor to ensuring provision of accurate results. The antigen-based PT program proved effective for assessing and supporting SARS-CoV-2 testing quality in low-resource settings. Its design allowed for deployment in decentralized locations, including those without advanced laboratory infrastructure or cold-chain systems. The sustained performance of PT materials under adverse storage conditions further supports its applicability in high-temperature field environments. High pass rates across diverse testing sites affirm that frontline health workers can perform rapid diagnostic tests accurately, provided they receive appropriate training and oversight. However, the recurrent false positives highlight the need for better training, particularly in result interpretation, and stricter adherence to test protocols.\u003c/p\u003e \u003cp\u003eThe model demonstrated in this study offers a cost-effective and scalable approach to external quality assessment in LMICs, with potential applicability beyond SARS-CoV-2. Future efforts should focus on increasing site coverage, improving digital result reporting, and integrating corrective action plans into national laboratory systems to ensure sustainability and continuous improvement in diagnostic quality\u003c/p\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eETHICS APPROVAL\u003c/h2\u003e \u003cp\u003eEthical permission and approval to conduct this study was sought from National Health Laboratory Diagnostic Services. All methods used in this study were performed in accordance with the relevant guidelines and regulations. Administrative clearance was obtained from National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory, Kampala, Uganda. It is worth noting that all enrolled sites were required to complete a Confidentiality Waiver and Participant Biosafety Compliance Letter Agreement before participation.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eETHICS APPROVAL\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical permission and approval to conduct this study was sought from National Health Laboratory Diagnostic Services. All methods used in this study were performed in accordance with the relevant guidelines and regulations. Administrative clearance was obtained from National Tuberculosis Reference Laboratory/WHO Supranational Reference Laboratory, Kampala, Uganda. It is worth noting that all enrolled sites were required to complete a Confidentiality Waiver and Participant Biosafety Compliance Letter Agreement before participation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll relevant data are within the paper and its Supporting Information files.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone to declare\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe author(s) received no special funding for this work. The financial support to run all the above activities was part of the COVID-19 Response Mechanism (C19RM) regional Global fund through the East, Central and Southern Africa (ECSA) Health Community Project to the Supra-National Reference Laboratory of Uganda\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors’ contributions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHNS PL IA JMK and KM: Contributed to the conception of the study;\u003c/p\u003e\n\u003cp\u003eHNS PL IA JMK JN KM and MLJ: Contributed to the design of the work;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHNS PL IA JMK WI KM PU: Contributed to the acquisition and analysis of data;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHNS PL IA JMK JN KM PU KF and MLJ: Contributed to the interpretation of data;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHNS PL IA JMK JN KM PU KF and MLJ: Drafted the work and substantively revised it; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHNS PL IA JMK JN KM PU WI KF and MLJ:\u0026nbsp; Approved the submitted version;\u003c/p\u003e\n\u003cp\u003eHNS PL IA JMK JN KM PU WI KF and MLJ: Agreed both to be personally accountable for the author's own contributions and to ensure that questions related to the accuracy or integrity of any part of the work, even ones in which the author was not personally involved, appropriately investigated, resolved, and the resolution documented in the literature.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe express our sincere appreciation to all the participants who took part in this proficiency testing (PT) initiative, as well as the dedicated team at the Supra-National Reference Laboratory of Uganda for their technical expertise and administrative contributions. We also gratefully acknowledge the valuable training and guidance provided by Kyle DeGruy and Patricia Hall from the Division of Global HIV and TB, International Laboratory Branch, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA. Additionally, we recognize the support of the Regional Global Fund through the East, Central, and Southern Africa (ECSA) Health Community Project.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWorld Health Organization (WHO). 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SARS-CoV-2 antigen-detecting rapid diagnostic tests, 2021.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"External quality assurance, SARS-CoV-2, Antigen-RDT, Quality control, COVID-19, Proficiency testing, Sub-Saharan Africa","lastPublishedDoi":"10.21203/rs.3.rs-8568737/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8568737/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eIntroduction\u003c/strong\u003e: Reliable approaches for evaluating the competency of health workers in performing SARS-CoV-2 antigen rapid diagnostic tests (Ag-RDTs) remain limited across sub-Saharan African laboratories, community settings, and primary health facilities. To address this gap, the WHO Supranational Reference Laboratory in Kampala, Uganda, established a proficiency testing (PT) program.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eSARS-CoV-2 antigen PT panels were developed at the Kampala SRL and distributed to 12 sub-Saharan countries. Each round involved five blinded PT samples, provided twice annually to 764 testing sites between November 2021 and November 2024. Competency was evaluated by comparing reported results with expected outcomes, assigning percentage scores, and delivering feedback reports.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eThe PT materials demonstrated stability for up to 56 days at temperatures as high as 46°C. The average pass rate exceeded 87% across all rounds, with the highest performance reaching 95%. Participation across the 12 countries declined from 53.1% to 38.1% over three years, primarily due to reduced COVID-19 testing demand.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eThis study shows that the developed SARS-CoV-2 antigen PT panels are a feasible option for external quality assessment in resource-limited settings. Strengthening quality management systems, providing refresher training, and expanding PT programs to remote facilities are critical for sustaining high-quality COVID-19 diagnostics.\u003c/p\u003e","manuscriptTitle":"Developing a reproducible quality COVID-19 RDT proficiency testing scheme: A rapid response to quality assured COVID-19 point of care testing","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-16 14:56:07","doi":"10.21203/rs.3.rs-8568737/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"20fafbd6-589b-4753-9aef-c0cbacc573b2","owner":[],"postedDate":"January 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-11T19:39:33+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-16 14:56:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8568737","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8568737","identity":"rs-8568737","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}