Association between Schistosoma mansoni infection and fecal occult blood in schoolchildren in Mbita, Suba North Sub-County, western Kenya

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Ngetich, Sammy Njenga, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7142467/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Jan, 2026 Read the published version in Tropical Medicine and Health → Version 1 posted 10 You are reading this latest preprint version Abstract Fecal occult blood (FOB) is a reliable indicator of bowel morbidity, yet its utility in the context of intestinal schistosomiasis remains inadequately characterized. To address this gap, we conducted a pre-post intervention study to evaluate the potential of FOB as a surrogate marker of Schistosoma mansoni -induced intestinal morbidity among preschool-aged (3–5 years) and school-aged (9–14 years) children in the Mbita Health Demographic Surveillance System, located along the shores and islands of Lake Victoria, Suba North sub-county, western Kenya. A total of 611 children from 10 primary schools were screened for S. mansoni infection prior to praziquantel (PZQ) treatment, and 584 were re-evaluated six weeks post-treatment. In addition to S. mansoni parasitological examination, FOB testing, malaria diagnosis, point-of-care hemoglobin measurement, and assessment of soil-transmitted helminth infections were performed both before and after treatment. Associations between S. mansoni infection and FOB positivity were analyzed using Pearson’s chi-square test and logistic regression. S. mansoni infection prevalence was high overall, particularly among SAC (77.4%) compared to PSAC (66.5%). Prior to treatment, over 75% of infected children were FOB-positive. Significant reductions in both S. mansoni infection and FOB positivity were observed six weeks after PZQ treatment (P < 0.01). Notably, PSAC residing on islands exhibited a higher likelihood of FOB positivity than those on the mainland. Our findings demonstrate a significant association between S. mansoni infection and FOB positivity. These results suggest that FOB testing may serve as a practical and scalable tool to monitor treatment-associated reductions in intestinal morbidity due to S. mansoni in endemic settings. Figures Figure 1 Figure 2 Introduction Schistosomiasis, a prevalent neglected tropical disease, remains a significant global health concern. It affects over 230 million people worldwide, with an estimated 779 million at risk of infection. Predominantly in Africa, Asia, the Caribbean, and South America (WHO, 2022 ), schistosomiasis imposes a substantial burden, particularly in Sub-Saharan Africa (Aula et al., 2021 ). In this region alone, it accounts for up to 90% of infections leading to an estimated loss of 3 million Disability Adjusted Life Years (DALYs) (Herricks et al., 2017 ), and 200,000 related deaths annually (Verjee, 2019 ). The impact is most profound in impoverished populations (Adenowo et al., 2015 ). The primary aetiological agent for schistosomiasis in Sub-Saharan Africa is Schistosoma mansoni , transmitted by freshwater Biomphalaria spp snails. It manifests as intestinal schistosomiasis characterized by symptoms such as abdominal pain, diarrhea, blood in stool, polyposis, and rectal bleeding (Colley et al., 2014 ). In Egypt, colorectal polyps are considered a potential cause of rectal bleeding in children that is regularly overlooked (El-Shabrawi et al., 2011 ). Anemia and hepatosplenic complications have also been associated with S. mansoni infection among schoolchildren in western Kenya (Butler et al., 2012 ; Samuels et al., 2012 ), underscoring the urgency of effective control measures. Morbidity control has been the cornerstone of schistosomiasis management strategies, with mass chemotherapy employing praziquantel as the primary intervention. Targeting endemic communities, particularly school-aged children with the highest infection burden, has been pivotal (WHO, 2022 ). More recently, efforts have expanded to include preschool-aged children, recognizing their vulnerability to infection (Osakunor et al., 2018 ). Following years of mass chemotherapy, the prevalence of S. mansoni infection and intensity has reduced by over 50% (Abudho et al., 2018 ; Kokaliaris et al., 2022 ; Mwandawiro et al., 2019 ), accompanied by a significant decline in schistosomiasis-associated morbidities (Andrade et al., 2017 ; King et al., 2020 ). Nevertheless, morbidity reduction reported in these studies is related to reduced infection intensity, a proxy indicator that is likely not sufficient to measure the success of mass chemotherapy. Therefore, there is a pressing need for more precise indicators that gauge the effectiveness of schistosomiasis control programs. In the context of S. mansoni infection, more research has emphasized largely on ultrasonographic examination of the abdomen and liver (Andrade et al., 2017 ; Davis et al., 2015 ; King et al., 2020 ). Evidence on the impact of treatment on intestinal morbidity in young children, however, remains scarce. For many years, faecal occult blood (FOB) test, indicative of hidden blood in the stool, has been used as a screening test for intestinal morbidities including those related to colorectal cancer (Hewitson et al., 2007 ; Kaur et al., 2024 ). The importance of FOB as a potential surrogate marker of bowel morbidity linked to gastrointestinal parasites is also increasing (Kanzaria et al., 2005 ; Patel et al., 2021 ; Shehab et al., 2023 ; Wakid, 2010 ). While some studies have found evidence of a correlation between S. mansoni infection and FOB (Betson et al., 2012 ; Bustinduy et al., 2013 ), these findings have not comprehensively addressed the peak age group for schistosome infections, particularly children aged 9 to 14 years (Colley et al., 2014 ). The chances of observing a reduction in morbidity after treatment are probably high in this age group. In this study, we sought to address this gap in knowledge by assessing the applicability of faecal occult blood as a surrogate indicator of S. mansoni -induced bowel morbidity in school-aged children (9–14 years) and preschool-aged children (3–5 years) as a comparator group. This study aims to bridge this gap by evaluating the utility of FOB as an indicator of S. mansoni -induced bowel morbidity in school-aged children (9–14 years) compared to preschool-aged children (3–5 years). By doing so, we seek to provide valuable insights into the effectiveness of current control strategies and contribute to the refinement of monitoring and evaluation efforts in schistosomiasis management. Methods Study area We conducted this study in Suba North sub-county, Homa Bay County, situated on the shores of Lake Victoria in western Kenya. We selected four administrative locations: Gembe East and West on the mainland, and Rusinga East and West on the island within the study area covered by the Mbita health demographic surveillance system (HDSS) for sampling school locations (Fig. 1 ). The Mbita HDSS is predominantly rural, characterized by fishing as the primary economic activity, and supplemented by small-scale farming, particularly among lakeside communities (Wanyua et al., 2013 ). The population heavily relies on the lake water for domestic purposes such as laundry, dishwashing, and recreational activities like swimming. This frequent exposure to contaminated water significantly contributes to the high prevalence of S. mansoni infection in the region, particularly among school-aged children (Chadeka et al., 2019 ; Nagi et al., 2014 ; Odiere et al., 2012 ; Takeuchi et al., 2019 ). Study design This study employed a pre-post design targeting preschool-aged children and school-aged children in selected primary schools. We used cluster sampling to select ten primary schools from 54 primary schools in the Mbita HDSS area. In each selected school, all pupils in the preprimary one (PP1) and 4th grade whose parents or legal guardians consented to the study were recruited. In Kenya, children typically enrol in grade 1 at 6, thus the majority of children in PP1 class and 4th grade fall within the targeted age groups of 3–5 years and 9–14 years, respectively. This study recruited a total of 672 preschool-aged, and school-aged children from a target population (PP1 class and 4th -grade) of 3670 pupils in schools covered by the Mbita HDSS. We excluded pupils enrolled in other schistosomiasis-related studies. Trained field assistants from the local community obtained informed consent from parents or legal guardians at the household level and collected pupils’ details including the name, class, age, gender, and house geographical location. Parasitological Examination All enrolled pupils were provided with labelled specimen containers for stool and urine samples, each assigned a unique identification number and instructed on proper usage. Trained field workers and class teachers assisted PP1 pupils in collecting stool and urine samples. Sample collection was conducted early in the morning over two consecutive days within the school premises, with transportation to the NUITM-KEMRI field laboratory in Mbita for testing. Samples were transported in cooler boxes with ice packs. Follow-up visits were conducted to ensure comprehensive sample collection. The Kato-Katz technique detected S. mansoni and other soil-transmitted helminth infections, including hookworm, Trichuris trichiura , and Ascaris lumbricoides . The method involved preparing duplicate thick faecal smears per sample, with four laboratory technicians examining under a light microscope within 24 hours of collection. Parasite egg quantification per gram of feces (EPG) was determined following WHO guidelines, categorizing S. mansoni infection intensity as light (1–99 EPG), moderate (100–399 EPG), or heavy (≥ 400 EPG) (WHO, 2019). Presence of S. mansoni antigen was also detected using a urine-based immunochromatographic circulating cathodic antigen (CCA) cassette test (Schisto POC-CCA™, Pretoria, South Africa). Positive results were indicated by the detection of at least one parasite egg using the Kato-Katz method or the presence of a pink band in the test area for CCA testing. These procedures were repeated six weeks after treatment for all study participants. We also tested for Plasmodium falciparum infection using antigen based rapid diagnostic test (STANDARD™ Q Malaria p.f Ag test, South Korea) due to high transmission of malaria in the study area. Morbidity assessment: Fecal occult blood (FOB) and Anemia Following the manufacturer's instructions, we detected faecal occult blood using a rapid visual immunoassay (Polymed Accurate, India). Briefly, the specimen was obtained by inserting the applicator stick into three different sites of the faecal sample and vigorously mixed with the extraction buffer. Subsequently, three drops of the solution were dispensed into the well of the test device. The results were interpreted after a 5-minute incubation period, and recorded as either, negative, or positive for any discernable colouration in the test region. This test was administered on a single stool sample both before and after treatment with praziquantel. We collected finger prick blood sample from each study participant to assess hemoglobin levels using a Hemocue Hb 201 + photometer (HemoCue, Angelholm, Sweden). Previously, studies have reported association between S. mansoni infection and anemia (Butler et al., 2012 ; Valice et al., 2018 ). In this study, anemia was defined as a hemoglobin level below 11, 11.5, and 12g/dl for pupils under 5, 5 to 11, and 12 to 14 years respectively. The severity of anemia was further classified based on age-specific cut-off values established by the World Health Organization (WHO, 2011 ). Treatment All the study participants who tested positive for S. mansoni infection, confirmed by either Kato-Katz or CCA were promptly administered a two-dose regimen of praziquantel treatment. The initial dose, calculated at 40 mg/kg body weight was administered at baseline, followed by a second dose 2 weeks after the initial treatment, administered by licensed clinicians. Subsequently, all participants underwent re-examination six weeks after treatment, and those still found infected with S. mansoni were administered an additional single dose of praziquantel. Concurrently, pupils diagnosed with STH infections received albendazole, while those with malaria were treated with artemether-lumefantrine. Furthermore, pupils identified with low hemoglobin levels were supplemented with folate tablets to address any underlying deficiencies. Data analysis Data collected during the study were entered into a Microsoft Excel spreadsheet and subsequently imported into R software version 3.6.1 for analysis. The normality of the data was assessed using the Shapiro-Wilk test. At the univariate level, continuous variables were summarized using arithmetic mean while categorical variables were presented as percentages. For the evaluation of S. mansoni intensity, EPG was computed by multiplying the number of schistosome eggs per Kato–Katz slide by 24, and then classified according to the established WHO guidelines into light(1–99 EPG), moderate(100–399 EPG), and heavy (≥ 400 EPG) infection categories. The Pearson chi-square (χ2) test examined associations between categorical variables at the bivariate level. Subsequently, multivariate analyses were conducted employing logistic regression models to assess the association between S. mansoni infection and faecal occult blood while adjusting for potential confounders such as gender, geographical location, anemia and malaria status. Statistical significance was determined at a p-value ≤ 0.05 with a 95% confidence interval (CI), indicating robust evidence of associations. Ethical consideration This study received approval from the Institutional Scientific and Ethics Review Committees of the University of Eastern Africa Baraton (UEAB/ISERC/39/07/2022) and the Kenya Medical Research Institute (KEMRI/SERU No. 4174) and further receiving a research license granted by the National Commission for Science, Technology, and Innovation (NACOSTI/P/22/19457), Kenya. Authorization to carry out the study was also obtained from both the Ministry of Education (MOE) and Health (MOH), Homa Bay County, Kenya. Before enrollment, written consent was obtained from parents or guardians, accompanied by assent from the participating children, ensuring full compliance with ethical standards and the protection of participants’ rights. Results Out of the 672 enrolled participants, 611 were included in the analysis before treatment, with 584 re-examined six weeks after treatment. Among 611 participants with complete data, 388 (63.5%) resided in mainland locations, specifically Gembe East and Gembe West. The majority of participants (52.2%) were preschool-aged children (PSAC), between 3 and 5 years, with mean age of 4 years. In contrast, school-aged children (SAC) had a mean age of 11 years, with their ages ranging from 9 to 14 years. Across both age groups (PSAC and SAC), the number of male participants was slightly higher compared to females. Demographic characteristics of the study population were comparable before and after treatment as detailed in Table 1 . The prevalence of S. mansoni infection, fecal occult blood, anaemia, malaria, and soil-transmitted helminths (STH) at the two-time points (before and after treatment) are presented in Table 2 . Overall, the prevalence of S. mansoni infection, determined by both Kato-Katz and circulating cathodic antigen (CCA) tests, was 66.5% (95% Cl 60.9–71.6) and 77.4% (95% Cl 72.1–82.0) among PSAC and SAC, respectively. Majority of SAC with S. mansoni infection exhibited moderate (23.6%) and heavy (24%) infection intensities. Conversely, a proportion of infected PSAC had light infections (20.7%) compared to moderate (10.7%) and heavy (7.8%) infections. Significant reductions ( P < 0.001) in both the prevalence of S. mansoni infection and intensity were observed between the two-time points among PSAC and SAC. Before treatment, the prevalence of faecal occult blood (FOB) was higher in SAC (66.1%) compared to PSAC (41.7%). Similarly, over three-quarters of S. mansoni infected PSAC (81%) and SAC (84%) were positive for FOB (Table 2 , Fig. 2 ). SAC who tested positive for S. mansoni infection had ten odds higher of occult blood in stool ( P < 0.001). PSAC infected with S. mansoni infection, on the other hand, were about three times more likely to exhibit positive fecal occult blood compared to uninfected children ( P < 0.01) as shown in Table 3 . Additionally, PSAC residing on the Island showed a 2-fold higher likelihood of occult blood in stool compared to those from the mainland location, albeit significant only before treatment ( P = 0.01). Female PSAC with S. mansoni infection showed 1.5 odds higher of fecal occult blood, however, the association was not statistically significant ( P = 0.085). After treatment, there was a substantial reduction in FOB positivity among S. mansoni -infected PSAC (from 81–28%; p < 0.001) and SAC (from 84–25%; p < 0.001), as depicted in Fig. 2 . A significant association between S. mansoni infection and FOB in both PSAC and SAC was also evident, even after adjusting for gender and location ( P < 0.01) as shown in Table 3 . According to WHO age-specific haemoglobin cut-off levels, 48% (95% Cl 42.3–53.6) of PSAC were anaemic, while the prevalence of anaemia among SAC before treatment was 34.2% (95% Cl 28.9–40.0). Low hemoglobin levels indicative of anemia did not demonstrate a significant association with occult blood loss in either group when considering both malaria and S. mansoni infection status. Malaria ( P. falciparum ) and STH ( Trichuris trichiura and hookworm) exhibited low prevalence rates among the study participants, with no cases of Ascaris lumbricoides detected before and after treatment. A significant decline (p = 0.023) in the proportion of anaemia (48–38.6%) was observed among PSAC. However, no significant reductions were noted in malaria, Trichuris trichiura , and hookworm infections (Table 2 ). Table 1 Demographic profile of the study population Variable Number (%) P Before treatment ( n = 611) After treatment ( n = 584) Preschool-aged children (PSAC) n = 319 n = 298 0.726 Age (years) Range 3–5 3–5 - Mean 4 4 - Gender Male 163 (51.1) 151 (50.7) 0.979 Female 156 (48.9) 147 (49.3) Location Gembe East (Mainland) 123 (38.6) 117 (39.3) 0.978 Gembe West (Mainland 75 (23.5) 68 (22.8) Rusinga East (Island) 49 (15.3) 43 (14.4) Rusinga West (Island) 72 (22.6) 40 (23.5) School-aged children (SAC) n = 292 n = 286 0.726 Age (years) Range 9–14 9–14 - Mean 11 11 - Gender Male 157 (53.8) 154 (53.8) 1.000 Female 135 (46.2) 132 (46.2) Location Gembe East (Mainland) 93 (31.8) 93 (32.5) 0.999 Gembe West (Mainland 97 (33.2) 94 (32.9) Rusinga East (Island) 37 (12.7) 36 (12.6) Rusinga West (Island) 65 (22.3) 63 (22.0) Table 2 Prevalence of Parasitic Infections, Fecal Occult Blood (FOB), and anaemia among preschool and school-aged children before and after treatment with praziquantel. Variable Prevalence, % (95% Cl) P Before treatment After treatment Preschool-aged children (3–5 years) n = 319 n = 298 0.726 * S. mansoni 1 66.5(60.9–71.6) 19.1(14.9–24.2) < 0.001 * S. mansoni 2 Light 20.7(16.4–25.6) 9.4(6.4–13.4) < 0.001 ** Moderate 10.7(7.6–14.7) 1.0(0.3–3.2) Heavy 7.8(5.2–11.5) 0.0 Trichuris trichiura 1.3(0.4–3.4) 0.0 1.000 ** Hookworm 0.3(0.0–2.0) 0.3(0.0-2.2) 0.374 ** Malaria ( P. falciparum ) 3.8(2.1–6.7) 5.0(2.9–8.3) 0.565 * FOB 41.7(36.3–47.3) 29.2(24.2–34.8) < 0.01 * Anemia status 3 48.0(42.3–53.6) 38.6(33.1–44.4) 0.023 * School-aged children (9–14 years) n = 292 n = 286 0.726 * S. mansoni 1 77.4(72.1–82.0) 20.6(16.2–25.9) < 0.001 * S. mansoni 2 Light 19.9(15.5–25.0) 8.4(5.6–12.4) < 0.001 ** Moderate 23.6(19.0–29.0) 1.7(0.6–4.3) Heavy 24.0(19.3–29.4) 1.0(0.3–3.3) Trichuris trichiura 0.3(0.0-2.2) 0.3(0.0-2.2) 1.000 ** Hookworm 0.0 0.3(0.0-2.2) 0.495 ** Malaria ( P. falciparum ) 5.1(3.0-8.5) 8.4(5.6–12.4) 0.163 * FOB 66.1(60.3–71.4) 29.0(23.9–34.7) < 0.001 * Anemia 3 34.2(28.9–40.0) 32.9(27.5–38.7) 0.793 * 1 Overall prevalence of S. mansoni infection by both Kato-Katz and circulating cathodic antigen (CCA) 2 S. mansoni intensity as determined by the number of eggs per gram (epg) of feces; light (1–99 epg), moderate (100–399 epg), heavy (> 400 epg) 3 Age specific hemoglobin (Hb) levels for anemia :Hb < 11gr/dl (< 5years), Hb < 11.5 (5–11 years), Hb < 12 (12-14years) * Pearson's Chi-squared test, ** Fisher's Exact Test Table 3 Association between S. mansoni infection and Fecal Occult Blood before and after treatment with praziquantel. Variable Fecal occult blood (FOB) Before treatment After treatment AOR (95% CI) P AOR (95% CI) P Preschool-aged children S. mansoni Positive 2.5(1.4–4.7) 0.002 2.5(1.3–4.6) 0.005 Gender Female 1.5(0.9–2.5) 0.085 0.9(0.5–1.5) 0.652 Location Island 2.0(1.2–3.4) 0.01 1.1(0.6–1.9) 0.758 Anemia status Anemic 1.0(0.6–1.6) 0.975 1.3(0.8–2.2) 0.342 Malaria Positive 0.5(0.1–1.9) 0.353 0.3(0.1–1.3) 0.166 School-aged children S. mansoni 1 Positive 9.9(5.0-20.6) < 0.001 5.4(2.9–10.6) < 0.0001 Gender Female 0.7(0.4–1.3) 0.307 0.7(0.4–1.3) 0.290 Location Island 1.4(0.7–2.8) 0.297 1.0(0.5–1.8) 0.991 Anemia status Anemic 1.0(0.5–1.8) 0.899 0.8(0.5–1.5) 0.586 Malaria Positive 0.4(0.1–1.5) 0.174 0.9(0.3–2.4) 0.838 In the model, S. mansoni infection status by both Kato-Katz (KK) and circulating cathodic antigen test (CCA) the predictor variable and FOB status was considered the outcome variable. The covariates included in the model were gender, and location which was broadly categorized into mainland (Gembe East and West) and Island (Rusinga East and West), anemia and malaria status. The reference groups included S. mansoni negative, male, mainland locations, non-anemia, and malaria-negative. Adjusted odds ratio (AOR) at 95% confidence interval (CI). Discussion This pre-post study explored the question of whether faecal occult blood (FOB) test could be utilized as a potential surrogate marker for assessing intestinal morbidities associated with S. mansoni infection before and after treatment with praziquantel. The study results indicated a significant association between S. mansoni infection and FOB in preschool and school-aged children, both before and after treatment. In addition, a significant decline in the prevalence of FOB was also observed after treating schoolchildren infected with S. mansoni . These findings highlight the significance of FOB as an indicator of intestinal schistosomiasis in our study population. It indicates that FOB test could be a valuable tool for monitoring and assessing the effectiveness of preventive and control measures in areas where schistosomiasis is endemic. In our study area, 77.4% of school-aged children and 66.5% of preschool-aged children were found to be infected with S. mansoni . The study also revealed that most infected school-aged children harboured heavy S. mansoni infections, whereas preschool-aged children typically had light infections. The results are consistent with the documented “schistosomiasis age-prevalence and age-intensity infection curves,” which indicate that initial infections can begin as early as 2 years old and reach their peak between ages 10 and 14 (Colley et al., 2014 ). The higher infection rates among school-aged children compared to preschool-aged children may be attributed to their frequent water contact activities, such as fishing and swimming, in areas contaminated with schistosomes (Odiere et al., 2012 ). The transmission of S. mansoni in the study area is known to be high (Chadeka et al., 2019 ; Sassa et al., 2020; Takeuchi et al., 2019 ). Despite the implementation of mass drug administration (MDA) with praziquantel, the persistence of infection over the years may be influenced by several factors, including water sources, sanitation, hygiene (Hailu et al., 2020; Musuva et al., 2021), and the distribution of intermediate host snails (Assaré et al., 2020; Mari et al., 2017), which could contribute to the rate of re-infection. Before this study, annual mass drug administration for treating intestinal schistosomiasis had not been carried out, which may have contributed to the high prevalence observed in the study area. This situation underscores the need to intensify treatment programs. The study found that the prevalence of FOB was 66.1% among school-aged children and 41.7% among preschool-aged children before treatment. These data add to the increasing evidence that preschool children are vulnerable to S. mansoni infection and schistosomiasis-related morbidity (Osakunor et al., 2018 ). Additionally, there were significant differences in FOB positivity rates between children infected with S. mansoni and those who were uninfected. This suggests that the presence of S. mansoni infection is a risk factor for occult gastrointestinal bleeding, as indicated by a positive FOB test. Previous reports have suggested that the presence of blood in the stool, a classic symptom of intestinal schistosomiasis, may be linked to intestinal perforations caused by schistosome eggs and gastrointestinal conditions such as bowel polyps resulting from chronic inflammation (Burke et al., 2009 ; Colley et al., 2014 ). Six weeks after the treatment, the prevalence of FOB among infected schoolchildren decreased significantly. This indicates that the rate of FOB positivity appeared to decline alongside the reduction in infection levels, highlighting the effectiveness of schistosomiasis treatment. The reduction in FOB positivity after treatment might also reflect a temporary improvement in the intestinal mucosa among the infected schoolchildren. Importantly, we demonstrated a positive correlation between S. mansoni infection and FOB in our sample population. This finding aligns with several studies (Betson et al., 2010 , 2012 ; Bustinduy et al., 2013 ) that have emphasized the feasibility and reliability of FOB as a field-applicable tool for monitoring changes in intestinal morbidity in young children following mass chemotherapy. The present study extends these findings by focusing mainly on an older cohort of schoolchildren aged 9 to 14 years, an epidemiologic age group that was underrepresented in the aforementioned studies. Furthermore, a two-dose regimen of praziquantel, administered two weeks apart, was provided to the infected children to improve the drug treatment (Colley et al., 2014 ) in our study area, where frequent exposure to contaminated water sources increases the likelihood of re-infection. In Egypt, the association between FOB and S. mansoni was not significant both before and after treatment among sampled patients aged 8 to 14 years (Shehab et al., 2023 ). These conflicting results might be partially attributed to differences in the level or intensity of infections, which could impact the correlation between the presence of S. mansoni and occult intestinal bleeding. A higher worm burden (heavy infection) has been associated with severe schistosomiasis complications, but the exact relationship is not fully understood (Andrade et al., 2017 ), possibly due to complex interactions between the human host and the parasite (Mawa et al., 2021 ). In the context of Schistosoma japonicum , it has been suggested that heavy infections and occult blood loss may play a role in causing anemia (Kanzaria et al., 2005 ). However, the mechanisms underlying schistosomiasis-related anemia are still unclear, especially in regions where malaria is also endemic, for instance, western Kenya (Butler et al., 2012 ; Valice et al., 2018 ). After adjusting for malaria, our study found insufficient evidence linking FOB to anemia; therefore, other factors might be contributing to anemia in the region. Past studies have also indicated that, besides schistosomiasis, heavy infections with soil-transmitted helminths (STH) such as Trichuris trichiura and hookworm may lead to intestinal bleeding (Parija et al., 2017 ; Stoltzfus et al., 1996 ). However, in the context FOB, the correlation with STH remains uncertain due to insufficient evidence (Patel et al., 2021 ; Wakid, 2010 ; Wanachiwanawin et al., 2005 ). In our study, the overall prevalence of T. trichiura and hookworm was low (< 2%), likely due to the annual deworming program in the study area (Mwandawiro et al., 2019 ; Okoyo et al., 2023 ). This aligns with previous research that has also reported a low prevalence of STH in western Kenya (Chadeka et al., 2019 ; Nagi et al., 2014 ). In schistosomiasis-endemic areas, the effectiveness of mass chemotherapy with praziquantel is currently evaluated by monitoring changes in prevalence and infection intensity (Kokaliaris et al., 2022 ; Mwandawiro et al., 2019 ). Nonetheless, these indicators seem insufficient for evaluating the success of control programs because of inconsistencies in the relationship between infection intensity and morbidity prevalence in young children, especially in the case of S. mansoni (Wiegand et al., 2021 ). The study's results show a significant association between S. mansoni infection and FOB among preschool and school-aged children, providing important information for the effective management and control of schistosomiasis. Integrating the FOB test into regular monitoring programs would be useful for evaluating disease burden and measuring the effectiveness of control strategies on prevalence levels and schistosomiasis-related morbidity. This aligns with the WHO's call for comprehensive research to define indicators for assessing disease morbidity, as the new approach shifts from controlling morbidity to eliminating schistosomiasis as a public health concern (WHO, 2022 ). The FOB test can serve as a screening tool to gauge the severity and development of intestinal morbidity in children. Its ease of use, cost-effectiveness, and non-invasiveness make it a suitable tool for community-level epidemiological surveys, aiding in decisions regarding schistosomiasis control strategies. Limitations of the study FOB can be a secondary symptom of several infections commonly affecting children. In addition to schistosomes and helminths, bacterial pathogens such as enterohemorragic Escherichia.coli and shigellae may also cause blood in the stool upon infection (Kaur et al., 2025 ). Moreover, positive FOB test results have been observed among workers in Saudi Arabia infected with protozoan parasites such as Giardia lamblia and Entamoeba histolytica , although these findings were not statistically significant (Wakid, 2010 ). In our study, these bacterial and protozoan agents were not examined among the sampled participants. In Kenya, E. coli , shigella and E. histolytica are considered the main etiologies of bloody diarrhea in children (Njuguna et al., 2016 ; Nyanga et al., 2017 ). Therefore, future researchers could expand on these findings by investigating the prevalence of these pathogens and their association with FOB. This would aid in assessing the performance of FOB in monitoring and evaluation programs, and ultimately the overall success of schistosomiasis public health interventions. Conclusions This study highlights useful insights about the importance of FOB in schistosomiasis endemic areas, including Suba North sub-county in western Kenya. The research confirms the significant burden of intestinal schistosomiasis in our area and highlights a notable correlation between S. mansoni infection and FOB in preschool and school-aged children, both prior to and following praziquantel treatment. Thus, this study recommends enhancing the existing schistosomiasis control measures in the region and incorporating FOB into monitoring and evaluation programs. Declarations Funding This study was supported by a grant from the European & Developing Countries Clinical Trials Partnership (EDCTP), awarded to Evans Asena Chadeka (grant number TMACDF2019-2746). Additional support was provided through the Grants-in-Aid for International Scientific Research (A) by JSPS (17H01684 and 21H04852), and the SATREPS program by JICA and AMED (JP25jm0110027), awarded to Shinjiro Hamano. The funders had no role in study design, data collection and analysis, decision to publish, or writing of the manuscript. Author Contribution E.A.C. designed the overall study and acquired funding for the project. E.A.C., J.C.B and J.G. were responsible for the methodology. S.N. and S.H. supported the development and troubleshooting standard operation procedures (SOPs) for laboratory sample analyses. E.A.C. and J.G. supervised project planning and execution. J.C.B., E.A.C. and B.C.N. were involved in data collection and processing. J.C.B. carried out data curation, formal analysis and writing the original draft. All authors reviewed and edited the final manuscript. Data Availability Data used in this study is available upon request to the authors References Abudho, B. O., Ndombi, E. M., Guya, B., Carter, J. M., Riner, D. K., Kittur, N., Karanja, D. M. S., Secor, W. E., & Colley, D. G. (2018). Impact of Four Years of Annual Mass Drug Administration on Prevalence and Intensity of Schistosomiasis among Primary and High School Children in Western Kenya: A Repeated Cross-Sectional Study. The American Journal of Tropical Medicine and Hygiene , 98 (5), 1397–1402. https://doi.org/10.4269/ajtmh.17-0908 Adenowo, A. F., Oyinloye, B. E., Ogunyinka, B. I., & Kappo, A. P. (2015). Impact of human schistosomiasis in sub-Saharan Africa. 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D., Kaneko, S., Ichinose, Y., Matsumoto, S., Njenga, S. M., Hashizume, M., Shimada, M., & Hamano, S. (2014). Risk Factors and Spatial Distribution of Schistosoma mansoni Infection among Primary School Children in Mbita District, Western Kenya. PLoS Neglected Tropical Diseases , 8 (7), e2991. https://doi.org/10.1371/journal.pntd.0002991 Njuguna, C., Njeru, I., Mgamb, E., Langat, D., Makokha, A., Ongore, D., Mathenge, E., & Kariuki, S. (2016). Enteric pathogens and factors associated with acute bloody diarrhoea, Kenya. BMC Infectious Diseases , 16 (1), 477. https://doi.org/10.1186/s12879-016-1814-6 Nyanga, P. L., Onyuka, J., Webale, M. K., Were, T., & Budambula, V. (2017). Escherichia coli pathotypes and Shigella sero-groups in diarrheic children in Nairobi city, Kenya. Gastroenterology and Hepatology from Bed to Bench , 10 (3), 220–228. Odiere, M. R., Rawago, F. O., Ombok, M., Secor, W. E., Karanja, D. M., Mwinzi, P. N., Lammie, P. J., & Won, K. (2012). 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PLOS Neglected Tropical Diseases , 15 (5), e0009444. https://doi.org/10.1371/journal.pntd.0009444 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 26 Jan, 2026 Read the published version in Tropical Medicine and Health → Version 1 posted Editorial decision: Revision requested 16 Aug, 2025 Reviews received at journal 10 Aug, 2025 Reviewers agreed at journal 04 Aug, 2025 Reviews received at journal 31 Jul, 2025 Reviewers agreed at journal 31 Jul, 2025 Reviewers agreed at journal 30 Jul, 2025 Reviewers invited by journal 29 Jul, 2025 Editor assigned by journal 29 Jul, 2025 Submission checks completed at journal 29 Jul, 2025 First submitted to journal 16 Jul, 2025 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. 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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-7142467","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":493213291,"identity":"e097d8c4-fdac-4f8b-9b51-70b651bbc7f4","order_by":0,"name":"Joy Chelangat Biegon","email":"","orcid":"","institution":"Kenya Medical Research Institute (KEMRI)","correspondingAuthor":false,"prefix":"","firstName":"Joy","middleName":"Chelangat","lastName":"Biegon","suffix":""},{"id":493213292,"identity":"875673a3-ecb7-4655-8d66-9c21d3fb13c8","order_by":1,"name":"John Gachohi","email":"","orcid":"","institution":"Jomo Kenyatta University of Agriculture and Technology (JKUAT)","correspondingAuthor":false,"prefix":"","firstName":"John","middleName":"","lastName":"Gachohi","suffix":""},{"id":493213293,"identity":"3c8498d5-395f-4bd9-88dc-d70d12617c4d","order_by":2,"name":"Benard C. 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It affects over 230\u0026nbsp;million people worldwide, with an estimated 779\u0026nbsp;million at risk of infection. Predominantly in Africa, Asia, the Caribbean, and South America (WHO, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), schistosomiasis imposes a substantial burden, particularly in Sub-Saharan Africa (Aula et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). In this region alone, it accounts for up to 90% of infections leading to an estimated loss of 3\u0026nbsp;million Disability Adjusted Life Years (DALYs) (Herricks et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), and 200,000 related deaths annually (Verjee, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The impact is most profound in impoverished populations (Adenowo et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2015\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe primary aetiological agent for schistosomiasis in Sub-Saharan Africa is \u003cem\u003eSchistosoma mansoni\u003c/em\u003e, transmitted by freshwater \u003cem\u003eBiomphalaria\u003c/em\u003e spp snails. It manifests as intestinal schistosomiasis characterized by symptoms such as abdominal pain, diarrhea, blood in stool, polyposis, and rectal bleeding (Colley et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). In Egypt, colorectal polyps are considered a potential cause of rectal bleeding in children that is regularly overlooked (El-Shabrawi et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Anemia and hepatosplenic complications have also been associated with \u003cem\u003eS. mansoni\u003c/em\u003e infection among schoolchildren in western Kenya (Butler et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Samuels et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2012\u003c/span\u003e), underscoring the urgency of effective control measures.\u003c/p\u003e\u003cp\u003eMorbidity control has been the cornerstone of schistosomiasis management strategies, with mass chemotherapy employing praziquantel as the primary intervention. Targeting endemic communities, particularly school-aged children with the highest infection burden, has been pivotal (WHO, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). More recently, efforts have expanded to include preschool-aged children, recognizing their vulnerability to infection (Osakunor et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Following years of mass chemotherapy, the prevalence of \u003cem\u003eS. mansoni\u003c/em\u003e infection and intensity has reduced by over 50% (Abudho et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Kokaliaris et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Mwandawiro et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), accompanied by a significant decline in schistosomiasis-associated morbidities (Andrade et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; King et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Nevertheless, morbidity reduction reported in these studies is related to reduced infection intensity, a proxy indicator that is likely not sufficient to measure the success of mass chemotherapy. Therefore, there is a pressing need for more precise indicators that gauge the effectiveness of schistosomiasis control programs.\u003c/p\u003e\u003cp\u003eIn the context of \u003cem\u003eS. mansoni\u003c/em\u003e infection, more research has emphasized largely on ultrasonographic examination of the abdomen and liver (Andrade et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Davis et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; King et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Evidence on the impact of treatment on intestinal morbidity in young children, however, remains scarce. For many years, faecal occult blood (FOB) test, indicative of hidden blood in the stool, has been used as a screening test for intestinal morbidities including those related to colorectal cancer (Hewitson et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Kaur et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). The importance of FOB as a potential surrogate marker of bowel morbidity linked to gastrointestinal parasites is also increasing (Kanzaria et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Patel et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Shehab et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Wakid, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). While some studies have found evidence of a correlation between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB (Betson et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Bustinduy et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), these findings have not comprehensively addressed the peak age group for schistosome infections, particularly children aged 9 to 14 years (Colley et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). The chances of observing a reduction in morbidity after treatment are probably high in this age group. In this study, we sought to address this gap in knowledge by assessing the applicability of faecal occult blood as a surrogate indicator of \u003cem\u003eS. mansoni\u003c/em\u003e-induced bowel morbidity in school-aged children (9\u0026ndash;14 years) and preschool-aged children (3\u0026ndash;5 years) as a comparator group. This study aims to bridge this gap by evaluating the utility of FOB as an indicator of \u003cem\u003eS. mansoni\u003c/em\u003e-induced bowel morbidity in school-aged children (9\u0026ndash;14 years) compared to preschool-aged children (3\u0026ndash;5 years). By doing so, we seek to provide valuable insights into the effectiveness of current control strategies and contribute to the refinement of monitoring and evaluation efforts in schistosomiasis management.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cb\u003eStudy area\u003c/b\u003e\u003c/p\u003e\u003cp\u003eWe conducted this study in Suba North sub-county, Homa Bay County, situated on the shores of Lake Victoria in western Kenya. We selected four administrative locations: Gembe East and West on the mainland, and Rusinga East and West on the island within the study area covered by the Mbita health demographic surveillance system (HDSS) for sampling school locations (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The Mbita HDSS is predominantly rural, characterized by fishing as the primary economic activity, and supplemented by small-scale farming, particularly among lakeside communities (Wanyua et al., \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). The population heavily relies on the lake water for domestic purposes such as laundry, dishwashing, and recreational activities like swimming. This frequent exposure to contaminated water significantly contributes to the high prevalence of \u003cem\u003eS. mansoni\u003c/em\u003e infection in the region, particularly among school-aged children (Chadeka et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Nagi et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Odiere et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Takeuchi et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2019\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cb\u003eStudy design\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThis study employed a pre-post design targeting preschool-aged children and school-aged children in selected primary schools. We used cluster sampling to select ten primary schools from 54 primary schools in the Mbita HDSS area. In each selected school, all pupils in the preprimary one (PP1) and 4th grade whose parents or legal guardians consented to the study were recruited. In Kenya, children typically enrol in grade 1 at 6, thus the majority of children in PP1 class and 4th\u003c/p\u003e\u003cp\u003egrade fall within the targeted age groups of 3\u0026ndash;5 years and 9\u0026ndash;14 years, respectively. This study recruited a total of 672 preschool-aged, and school-aged children from a target population (PP1 class and 4th -grade) of 3670 pupils in schools covered by the Mbita HDSS. We excluded pupils enrolled in other schistosomiasis-related studies. Trained field assistants from the local community obtained informed consent from parents or legal guardians at the household level and collected pupils\u0026rsquo; details including the name, class, age, gender, and house geographical location.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eParasitological Examination\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAll enrolled pupils were provided with labelled specimen containers for stool and urine samples, each assigned a unique identification number and instructed on proper usage. Trained field workers and class teachers assisted PP1 pupils in collecting stool and urine samples. Sample collection was conducted early in the morning over two consecutive days within the school premises, with transportation to the NUITM-KEMRI field laboratory in Mbita for testing. Samples were transported in cooler boxes with ice packs. Follow-up visits were conducted to ensure comprehensive sample collection.\u003c/p\u003e\u003cp\u003eThe Kato-Katz technique detected \u003cem\u003eS. mansoni\u003c/em\u003e and other soil-transmitted helminth infections, including hookworm, \u003cem\u003eTrichuris trichiura\u003c/em\u003e, and \u003cem\u003eAscaris lumbricoides\u003c/em\u003e. The method involved preparing duplicate thick faecal smears per sample, with four laboratory technicians examining under a light microscope within 24 hours of collection. Parasite egg quantification per gram of feces (EPG) was determined following WHO guidelines, categorizing \u003cem\u003eS. mansoni\u003c/em\u003e infection intensity as light (1\u0026ndash;99 EPG), moderate (100\u0026ndash;399 EPG), or heavy (\u0026ge;\u0026thinsp;400 EPG) (WHO, 2019). Presence of \u003cem\u003eS. mansoni\u003c/em\u003e antigen was also detected using a urine-based immunochromatographic circulating cathodic antigen (CCA) cassette test (Schisto POC-CCA\u0026trade;, Pretoria, South Africa). Positive results were indicated by the detection of at least one parasite egg using the Kato-Katz method or the presence of a pink band in the test area for CCA testing. These procedures were repeated six weeks after treatment for all study participants. We also tested for \u003cem\u003ePlasmodium falciparum\u003c/em\u003e infection using antigen based rapid diagnostic test (STANDARD\u0026trade; Q Malaria p.f Ag test, South Korea) due to high transmission of malaria in the study area.\u003c/p\u003e\u003cp\u003e\u003cb\u003eMorbidity assessment: Fecal occult blood (FOB) and Anemia\u003c/b\u003e\u003c/p\u003e\u003cp\u003eFollowing the manufacturer's instructions, we detected faecal occult blood using a rapid visual immunoassay (Polymed Accurate, India). Briefly, the specimen was obtained by inserting the applicator stick into three different sites of the faecal sample and vigorously mixed with the extraction buffer. Subsequently, three drops of the solution were dispensed into the well of the test device. The results were interpreted after a 5-minute incubation period, and recorded as either, negative, or positive for any discernable colouration in the test region. This test was administered on a single stool sample both before and after treatment with praziquantel.\u003c/p\u003e\u003cp\u003eWe collected finger prick blood sample from each study participant to assess hemoglobin levels using a Hemocue Hb 201\u003csup\u003e+\u003c/sup\u003e photometer (HemoCue, Angelholm, Sweden). Previously, studies have reported association between \u003cem\u003eS. mansoni\u003c/em\u003e infection and anemia (Butler et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Valice et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). In this study, anemia was defined as a hemoglobin level below 11, 11.5, and 12g/dl for pupils under 5, 5 to 11, and 12 to 14 years respectively. The severity of anemia was further classified based on age-specific cut-off values established by the World Health Organization (WHO, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cb\u003eTreatment\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAll the study participants who tested positive for \u003cem\u003eS. mansoni\u003c/em\u003e infection, confirmed by either Kato-Katz or CCA were promptly administered a two-dose regimen of praziquantel treatment. The initial dose, calculated at 40 mg/kg body weight was administered at baseline, followed by a second dose 2 weeks after the initial treatment, administered by licensed clinicians. Subsequently, all participants underwent re-examination six weeks after treatment, and those still found infected with \u003cem\u003eS. mansoni\u003c/em\u003e were administered an additional single dose of praziquantel. Concurrently, pupils diagnosed with STH infections received albendazole, while those with malaria were treated with artemether-lumefantrine. Furthermore, pupils identified with low hemoglobin levels were supplemented with folate tablets to address any underlying deficiencies.\u003c/p\u003e\u003cdiv id=\"Sec2\" class=\"Section2\"\u003e\u003ch2\u003eData analysis\u003c/h2\u003e\u003cp\u003eData collected during the study were entered into a Microsoft Excel spreadsheet and subsequently imported into R software version 3.6.1 for analysis. The normality of the data was assessed using the Shapiro-Wilk test. At the univariate level, continuous variables were summarized using arithmetic mean while categorical variables were presented as percentages. For the evaluation of \u003cem\u003eS. mansoni\u003c/em\u003e intensity, EPG was computed by multiplying the number of schistosome eggs per Kato\u0026ndash;Katz slide by 24, and then classified according to the established WHO guidelines into light(1\u0026ndash;99 EPG), moderate(100\u0026ndash;399 EPG), and heavy (\u0026ge;\u0026thinsp;400 EPG) infection categories. The Pearson chi-square (χ2) test examined associations between categorical variables at the bivariate level. Subsequently, multivariate analyses were conducted employing logistic regression models to assess the association between \u003cem\u003eS. mansoni\u003c/em\u003e infection and faecal occult blood while adjusting for potential confounders such as gender, geographical location, anemia and malaria status. Statistical significance was determined at a p-value\u0026thinsp;\u0026le;\u0026thinsp;0.05 with a 95% confidence interval (CI), indicating robust evidence of associations.\u003c/p\u003e\u003cp\u003e\u003cb\u003eEthical consideration\u003c/b\u003e\u003c/p\u003e\u003cp\u003e This study received approval from the Institutional Scientific and Ethics Review Committees of the University of Eastern Africa Baraton (UEAB/ISERC/39/07/2022) and the Kenya Medical Research Institute (KEMRI/SERU No. 4174) and further receiving a research license granted by the National Commission for Science, Technology, and Innovation (NACOSTI/P/22/19457), Kenya. Authorization to carry out the study was also obtained from both the Ministry of Education (MOE) and Health (MOH), Homa Bay County, Kenya. Before enrollment, written consent was obtained from parents or guardians, accompanied by assent from the participating children, ensuring full compliance with ethical standards and the protection of participants\u0026rsquo; rights.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eOut of the 672 enrolled participants, 611 were included in the analysis before treatment, with 584 re-examined six weeks after treatment. Among 611 participants with complete data, 388 (63.5%) resided in mainland locations, specifically Gembe East and Gembe West. The majority of participants (52.2%) were preschool-aged children (PSAC), between 3 and 5 years, with mean age of 4 years. In contrast, school-aged children (SAC) had a mean age of 11 years, with their ages ranging from 9 to 14 years. Across both age groups (PSAC and SAC), the number of male participants was slightly higher compared to females. Demographic characteristics of the study population were comparable before and after treatment as detailed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003eThe prevalence of \u003cem\u003eS. mansoni\u003c/em\u003e infection, fecal occult blood, anaemia, malaria, and soil-transmitted helminths (STH) at the two-time points (before and after treatment) are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Overall, the prevalence of \u003cem\u003eS. mansoni\u003c/em\u003e infection, determined by both Kato-Katz and circulating cathodic antigen (CCA) tests, was 66.5% (95% Cl 60.9\u0026ndash;71.6) and 77.4% (95% Cl 72.1\u0026ndash;82.0) among PSAC and SAC, respectively. Majority of SAC with \u003cem\u003eS. mansoni\u003c/em\u003e infection exhibited moderate (23.6%) and heavy (24%) infection intensities. Conversely, a proportion of infected PSAC had light infections (20.7%) compared to moderate (10.7%) and heavy (7.8%) infections. Significant reductions (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) in both the prevalence of \u003cem\u003eS. mansoni\u003c/em\u003e infection and intensity were observed between the two-time points among PSAC and SAC.\u003c/p\u003e\u003cp\u003eBefore treatment, the prevalence of faecal occult blood (FOB) was higher in SAC (66.1%) compared to PSAC (41.7%). Similarly, over three-quarters of \u003cem\u003eS. mansoni\u003c/em\u003e infected PSAC (81%) and SAC (84%) were positive for FOB (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). SAC who tested positive for \u003cem\u003eS. mansoni\u003c/em\u003e infection had ten odds higher of occult blood in stool (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). PSAC infected with \u003cem\u003eS. mansoni\u003c/em\u003e infection, on the other hand, were about three times more likely to exhibit positive fecal occult blood compared to uninfected children (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01) as shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Additionally, PSAC residing on the Island showed a 2-fold higher likelihood of occult blood in stool compared to those from the mainland location, albeit significant only before treatment (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01). Female PSAC with \u003cem\u003eS. mansoni\u003c/em\u003e infection showed 1.5 odds higher of fecal occult blood, however, the association was not statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.085).\u003c/p\u003e\u003cp\u003eAfter treatment, there was a substantial reduction in FOB positivity among \u003cem\u003eS. mansoni\u003c/em\u003e-infected PSAC (from 81\u0026ndash;28%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and SAC (from 84\u0026ndash;25%; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. A significant association between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB in both PSAC and SAC was also evident, even after adjusting for gender and location (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01) as shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. According to WHO age-specific haemoglobin cut-off levels, 48% (95% Cl 42.3\u0026ndash;53.6) of PSAC were anaemic, while the prevalence of anaemia among SAC before treatment was 34.2% (95% Cl 28.9\u0026ndash;40.0). Low hemoglobin levels indicative of anemia did not demonstrate a significant association with occult blood loss in either group when considering both malaria and \u003cem\u003eS. mansoni\u003c/em\u003e infection status. Malaria (\u003cem\u003eP. falciparum\u003c/em\u003e) and STH (\u003cem\u003eTrichuris trichiura\u003c/em\u003e and hookworm) exhibited low prevalence rates among the study participants, with no cases of \u003cem\u003eAscaris lumbricoides\u003c/em\u003e detected before and after treatment. A significant decline (p\u0026thinsp;=\u0026thinsp;0.023) in the proportion of anaemia (48\u0026ndash;38.6%) was observed among PSAC. However, no significant reductions were noted in malaria, \u003cem\u003eTrichuris trichiura\u003c/em\u003e, and hookworm infections (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDemographic profile of the study population\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eNumber (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBefore treatment\u003c/p\u003e\u003cp\u003e(\u003cem\u003en\u0026thinsp;=\u003c/em\u003e\u0026thinsp;611)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAfter treatment\u003c/p\u003e\u003cp\u003e(\u003cem\u003en\u0026thinsp;=\u003c/em\u003e\u0026thinsp;584)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePreschool-aged children (PSAC)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;319\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003en\u0026thinsp;=\u003c/em\u003e\u0026thinsp;298\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.726\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years) Range\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3\u0026ndash;5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3\u0026ndash;5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender Male\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e163 (51.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e151 (50.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.979\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e156 (48.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e147 (49.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLocation Gembe East (Mainland)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e123 (38.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e117 (39.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003e0.978\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGembe West (Mainland\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e75 (23.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e68 (22.8)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRusinga East (Island)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e49 (15.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43 (14.4)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRusinga West (Island)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e72 (22.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e40 (23.5)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSchool-aged children (SAC)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;292\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;286\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.726\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years) Range\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9\u0026ndash;14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9\u0026ndash;14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender Male\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e157 (53.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e154 (53.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e1.000\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e135 (46.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e132 (46.2)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLocation Gembe East (Mainland)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e93 (31.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e93 (32.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003e0.999\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGembe West (Mainland\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e97 (33.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e94 (32.9)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRusinga East (Island)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e37 (12.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e36 (12.6)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRusinga West (Island)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e65 (22.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e63 (22.0)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\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\u003ePrevalence of Parasitic Infections, Fecal Occult Blood (FOB), and anaemia among preschool and school-aged children before and after treatment with praziquantel.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003ePrevalence, % (95% Cl)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBefore treatment\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAfter treatment\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePreschool-aged children\u003c/b\u003e (3\u0026ndash;5 years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;319\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003en\u0026thinsp;=\u003c/em\u003e\u0026thinsp;298\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.726\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eS. mansoni\u003c/em\u003e \u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e66.5(60.9\u0026ndash;71.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19.1(14.9\u0026ndash;24.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eS. mansoni\u003c/em\u003e \u003csup\u003e2\u003c/sup\u003e Light\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e20.7(16.4\u0026ndash;25.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9.4(6.4\u0026ndash;13.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.7(7.6\u0026ndash;14.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0(0.3\u0026ndash;3.2)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeavy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7.8(5.2\u0026ndash;11.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eTrichuris trichiura\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.3(0.4\u0026ndash;3.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.000\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHookworm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.3(0.0\u0026ndash;2.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.3(0.0-2.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.374\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMalaria (\u003cem\u003eP. falciparum\u003c/em\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.8(2.1\u0026ndash;6.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.0(2.9\u0026ndash;8.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.565\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFOB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e41.7(36.3\u0026ndash;47.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.2(24.2\u0026ndash;34.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.01\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnemia status \u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e48.0(42.3\u0026ndash;53.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e38.6(33.1\u0026ndash;44.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.023\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSchool-aged children\u003c/b\u003e (9\u0026ndash;14 years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;292\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;286\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.726\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eS. mansoni\u003c/em\u003e \u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e77.4(72.1\u0026ndash;82.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20.6(16.2\u0026ndash;25.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eS. mansoni\u003c/em\u003e \u003csup\u003e2\u003c/sup\u003e Light\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e19.9(15.5\u0026ndash;25.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.4(5.6\u0026ndash;12.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eModerate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23.6(19.0\u0026ndash;29.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.7(0.6\u0026ndash;4.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeavy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e24.0(19.3\u0026ndash;29.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0(0.3\u0026ndash;3.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eTrichuris trichiura\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.3(0.0-2.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.3(0.0-2.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.000\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHookworm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.3(0.0-2.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.495\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMalaria (\u003cem\u003eP. falciparum\u003c/em\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.1(3.0-8.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.4(5.6\u0026ndash;12.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.163\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFOB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e66.1(60.3\u0026ndash;71.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.0(23.9\u0026ndash;34.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnemia \u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.2(28.9\u0026ndash;40.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32.9(27.5\u0026ndash;38.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.793\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c4\" namest=\"c1\"\u003e\u003cp\u003e\u003csup\u003e1\u003c/sup\u003e Overall prevalence of \u003cem\u003eS. mansoni\u003c/em\u003e infection by both Kato-Katz and circulating cathodic antigen (CCA)\u003c/p\u003e\u003cp\u003e\u003csup\u003e2\u003c/sup\u003e \u003cem\u003eS. mansoni\u003c/em\u003e intensity as determined by the number of eggs per gram (epg) of feces; light (1\u0026ndash;99 epg), moderate (100\u0026ndash;399 epg), heavy (\u0026gt;\u0026thinsp;400 epg)\u003c/p\u003e\u003cp\u003e\u003csup\u003e3\u003c/sup\u003eAge specific hemoglobin (Hb) levels for anemia :Hb\u0026thinsp;\u0026lt;\u0026thinsp;11gr/dl (\u0026lt;\u0026thinsp;5years), Hb\u0026thinsp;\u0026lt;\u0026thinsp;11.5 (5\u0026ndash;11 years), Hb\u0026thinsp;\u0026lt;\u0026thinsp;12 (12-14years)\u003c/p\u003e\u003cp\u003e\u003csup\u003e*\u003c/sup\u003ePearson's Chi-squared test, \u003csup\u003e**\u003c/sup\u003eFisher's Exact Test\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eAssociation between \u003cem\u003eS. mansoni\u003c/em\u003e infection and Fecal Occult Blood before and after treatment with praziquantel.\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=\"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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003eFecal occult blood (FOB)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e\u003cb\u003eBefore treatment\u003c/b\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003e\u003cb\u003eAfter treatment\u003c/b\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAOR (95% CI)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAOR (95% CI)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePreschool-aged children\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eS. mansoni\u003c/em\u003e Positive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.5(1.4\u0026ndash;4.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.5(1.3\u0026ndash;4.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender Female\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.5(0.9\u0026ndash;2.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.085\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.9(0.5\u0026ndash;1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.652\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLocation Island\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.0(1.2\u0026ndash;3.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.1(0.6\u0026ndash;1.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.758\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnemia status Anemic\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.0(0.6\u0026ndash;1.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.975\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.3(0.8\u0026ndash;2.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.342\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMalaria Positive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.5(0.1\u0026ndash;1.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.353\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.3(0.1\u0026ndash;1.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.166\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSchool-aged children\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eS. mansoni\u003c/em\u003e \u003csup\u003e1\u003c/sup\u003e Positive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9.9(5.0-20.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.4(2.9\u0026ndash;10.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender Female\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.7(0.4\u0026ndash;1.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.307\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.7(0.4\u0026ndash;1.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.290\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLocation Island\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.4(0.7\u0026ndash;2.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.297\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.0(0.5\u0026ndash;1.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.991\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnemia status Anemic\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.0(0.5\u0026ndash;1.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.899\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.8(0.5\u0026ndash;1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.586\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMalaria Positive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.4(0.1\u0026ndash;1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.174\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.9(0.3\u0026ndash;2.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.838\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003eIn the model, \u003cem\u003eS. mansoni\u003c/em\u003e infection status by both Kato-Katz (KK) and circulating cathodic antigen test (CCA) the predictor variable and FOB status was considered the outcome variable.\u003c/p\u003e\u003cp\u003eThe covariates included in the model were gender, and location which was broadly categorized into mainland (Gembe East and West) and Island (Rusinga East and West), anemia and malaria status.\u003c/p\u003e\u003cp\u003eThe reference groups included \u003cem\u003eS. mansoni\u003c/em\u003e negative, male, mainland locations, non-anemia, and malaria-negative.\u003c/p\u003e\u003cp\u003eAdjusted odds ratio (AOR) at 95% confidence interval (CI).\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\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis pre-post study explored the question of whether faecal occult blood (FOB) test could be utilized as a potential surrogate marker for assessing intestinal morbidities associated with \u003cem\u003eS. mansoni\u003c/em\u003e infection before and after treatment with praziquantel. The study results indicated a significant association between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB in preschool and school-aged children, both before and after treatment. In addition, a significant decline in the prevalence of FOB was also observed after treating schoolchildren infected with \u003cem\u003eS. mansoni\u003c/em\u003e. These findings highlight the significance of FOB as an indicator of intestinal schistosomiasis in our study population. It indicates that FOB test could be a valuable tool for monitoring and assessing the effectiveness of preventive and control measures in areas where schistosomiasis is endemic.\u003c/p\u003e\u003cp\u003eIn our study area, 77.4% of school-aged children and 66.5% of preschool-aged children were found to be infected with \u003cem\u003eS. mansoni\u003c/em\u003e. The study also revealed that most infected school-aged children harboured heavy \u003cem\u003eS. mansoni\u003c/em\u003e infections, whereas preschool-aged children typically had light infections. The results are consistent with the documented \u0026ldquo;schistosomiasis age-prevalence and age-intensity infection curves,\u0026rdquo; which indicate that initial infections can begin as early as 2 years old and reach their peak between ages 10 and 14 (Colley et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). The higher infection rates among school-aged children compared to preschool-aged children may be attributed to their frequent water contact activities, such as fishing and swimming, in areas contaminated with schistosomes (Odiere et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). The transmission of \u003cem\u003eS. mansoni\u003c/em\u003e in the study area is known to be high (Chadeka et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Sassa et al., 2020; Takeuchi et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Despite the implementation of mass drug administration (MDA) with praziquantel, the persistence of infection over the years may be influenced by several factors, including water sources, sanitation, hygiene (Hailu et al., 2020; Musuva et al., 2021), and the distribution of intermediate host snails (Assar\u0026eacute; et al., 2020; Mari et al., 2017), which could contribute to the rate of re-infection. Before this study, annual mass drug administration for treating intestinal schistosomiasis had not been carried out, which may have contributed to the high prevalence observed in the study area. This situation underscores the need to intensify treatment programs.\u003c/p\u003e\u003cp\u003eThe study found that the prevalence of FOB was 66.1% among school-aged children and 41.7% among preschool-aged children before treatment. These data add to the increasing evidence that preschool children are vulnerable to \u003cem\u003eS. mansoni\u003c/em\u003e infection and schistosomiasis-related morbidity (Osakunor et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Additionally, there were significant differences in FOB positivity rates between children infected with \u003cem\u003eS. mansoni\u003c/em\u003e and those who were uninfected. This suggests that the presence of \u003cem\u003eS. mansoni\u003c/em\u003e infection is a risk factor for occult gastrointestinal bleeding, as indicated by a positive FOB test. Previous reports have suggested that the presence of blood in the stool, a classic symptom of intestinal schistosomiasis, may be linked to intestinal perforations caused by schistosome eggs and gastrointestinal conditions such as bowel polyps resulting from chronic inflammation (Burke et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Colley et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Six weeks after the treatment, the prevalence of FOB among infected schoolchildren decreased significantly. This indicates that the rate of FOB positivity appeared to decline alongside the reduction in infection levels, highlighting the effectiveness of schistosomiasis treatment. The reduction in FOB positivity after treatment might also reflect a temporary improvement in the intestinal mucosa among the infected schoolchildren.\u003c/p\u003e\u003cp\u003eImportantly, we demonstrated a positive correlation between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB in our sample population. This finding aligns with several studies (Betson et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2010\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Bustinduy et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) that have emphasized the feasibility and reliability of FOB as a field-applicable tool for monitoring changes in intestinal morbidity in young children following mass chemotherapy. The present study extends these findings by focusing mainly on an older cohort of schoolchildren aged 9 to 14 years, an epidemiologic age group that was underrepresented in the aforementioned studies. Furthermore, a two-dose regimen of praziquantel, administered two weeks apart, was provided to the infected children to improve the drug treatment (Colley et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) in our study area, where frequent exposure to contaminated water sources increases the likelihood of re-infection. In Egypt, the association between FOB and \u003cem\u003eS. mansoni\u003c/em\u003e was not significant both before and after treatment among sampled patients aged 8 to 14 years (Shehab et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). These conflicting results might be partially attributed to differences in the level or intensity of infections, which could impact the correlation between the presence of \u003cem\u003eS. mansoni\u003c/em\u003e and occult intestinal bleeding. A higher worm burden (heavy infection) has been associated with severe schistosomiasis complications, but the exact relationship is not fully understood (Andrade et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2017\u003c/span\u003e), possibly due to complex interactions between the human host and the parasite (Mawa et al., \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). In the context of \u003cem\u003eSchistosoma japonicum\u003c/em\u003e, it has been suggested that heavy infections and occult blood loss may play a role in causing anemia (Kanzaria et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). However, the mechanisms underlying schistosomiasis-related anemia are still unclear, especially in regions where malaria is also endemic, for instance, western Kenya (Butler et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Valice et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). After adjusting for malaria, our study found insufficient evidence linking FOB to anemia; therefore, other factors might be contributing to anemia in the region. Past studies have also indicated that, besides schistosomiasis, heavy infections with soil-transmitted helminths (STH) such as \u003cem\u003eTrichuris trichiura\u003c/em\u003e and hookworm may lead to intestinal bleeding (Parija et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Stoltzfus et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e1996\u003c/span\u003e). However, in the context FOB, the correlation with STH remains uncertain due to insufficient evidence (Patel et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Wakid, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Wanachiwanawin et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). In our study, the overall prevalence of \u003cem\u003eT. trichiura\u003c/em\u003e and hookworm was low (\u0026lt;\u0026thinsp;2%), likely due to the annual deworming program in the study area (Mwandawiro et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Okoyo et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). This aligns with previous research that has also reported a low prevalence of STH in western Kenya (Chadeka et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Nagi et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn schistosomiasis-endemic areas, the effectiveness of mass chemotherapy with praziquantel is currently evaluated by monitoring changes in prevalence and infection intensity (Kokaliaris et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Mwandawiro et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Nonetheless, these indicators seem insufficient for evaluating the success of control programs because of inconsistencies in the relationship between infection intensity and morbidity prevalence in young children, especially in the case of \u003cem\u003eS. mansoni\u003c/em\u003e (Wiegand et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). The study's results show a significant association between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB among preschool and school-aged children, providing important information for the effective management and control of schistosomiasis. Integrating the FOB test into regular monitoring programs would be useful for evaluating disease burden and measuring the effectiveness of control strategies on prevalence levels and schistosomiasis-related morbidity. This aligns with the WHO's call for comprehensive research to define indicators for assessing disease morbidity, as the new approach shifts from controlling morbidity to eliminating schistosomiasis as a public health concern (WHO, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The FOB test can serve as a screening tool to gauge the severity and development of intestinal morbidity in children. Its ease of use, cost-effectiveness, and non-invasiveness make it a suitable tool for community-level epidemiological surveys, aiding in decisions regarding schistosomiasis control strategies.\u003c/p\u003e\u003cp\u003e\u003cb\u003eLimitations of the study\u003c/b\u003e\u003c/p\u003e\u003cp\u003eFOB can be a secondary symptom of several infections commonly affecting children. In addition to schistosomes and helminths, bacterial pathogens such as enterohemorragic \u003cem\u003eEscherichia.coli\u003c/em\u003e and shigellae may also cause blood in the stool upon infection (Kaur et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2025\u003c/span\u003e). Moreover, positive FOB test results have been observed among workers in Saudi Arabia infected with protozoan parasites such as \u003cem\u003eGiardia lamblia\u003c/em\u003e and \u003cem\u003eEntamoeba histolytica\u003c/em\u003e, although these findings were not statistically significant (Wakid, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). In our study, these bacterial and protozoan agents were not examined among the sampled participants. In Kenya, \u003cem\u003eE. coli\u003c/em\u003e, shigella and \u003cem\u003eE. histolytica\u003c/em\u003e are considered the main etiologies of bloody diarrhea in children (Njuguna et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Nyanga et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Therefore, future researchers could expand on these findings by investigating the prevalence of these pathogens and their association with FOB. This would aid in assessing the performance of FOB in monitoring and evaluation programs, and ultimately the overall success of schistosomiasis public health interventions.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThis study highlights useful insights about the importance of FOB in schistosomiasis endemic areas, including Suba North sub-county in western Kenya. The research confirms the significant burden of intestinal schistosomiasis in our area and highlights a notable correlation between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB in preschool and school-aged children, both prior to and following praziquantel treatment. Thus, this study recommends enhancing the existing schistosomiasis control measures in the region and incorporating FOB into monitoring and evaluation programs.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eThis study was supported by a grant from the European \u0026amp; Developing Countries Clinical Trials Partnership (EDCTP), awarded to Evans Asena Chadeka (grant number TMACDF2019-2746). Additional support was provided through the Grants-in-Aid for International Scientific Research (A) by JSPS (17H01684 and 21H04852), and the SATREPS program by JICA and AMED (JP25jm0110027), awarded to Shinjiro Hamano. The funders had no role in study design, data collection and analysis, decision to publish, or writing of the manuscript.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eE.A.C. designed the overall study and acquired funding for the project. E.A.C., J.C.B and J.G. were responsible for the methodology. S.N. and S.H. supported the development and troubleshooting standard operation procedures (SOPs) for laboratory sample analyses. E.A.C. and J.G. supervised project planning and execution. J.C.B., E.A.C. and B.C.N. were involved in data collection and processing. J.C.B. carried out data curation, formal analysis and writing the original draft. All authors reviewed and edited the final manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData used in this study is available upon request to the authors\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAbudho, B. O., Ndombi, E. M., Guya, B., Carter, J. M., Riner, D. K., Kittur, N., Karanja, D. M. S., Secor, W. E., \u0026amp; Colley, D. G. (2018). Impact of Four Years of Annual Mass Drug Administration on Prevalence and Intensity of Schistosomiasis among Primary and High School Children in Western Kenya: A Repeated Cross-Sectional Study. \u003cem\u003eThe American Journal of Tropical Medicine and Hygiene\u003c/em\u003e, \u003cem\u003e98\u003c/em\u003e(5), 1397\u0026ndash;1402. https://doi.org/10.4269/ajtmh.17-0908\u003c/li\u003e\n\u003cli\u003eAdenowo, A. F., Oyinloye, B. E., Ogunyinka, B. I., \u0026amp; Kappo, A. P. (2015). Impact of human schistosomiasis in sub-Saharan Africa. \u003cem\u003eThe Brazilian Journal of Infectious Diseases\u003c/em\u003e, \u003cem\u003e19\u003c/em\u003e(2), 196\u0026ndash;205. https://doi.org/10.1016/j.bjid.2014.11.004\u003c/li\u003e\n\u003cli\u003eAndrade, G., Bertsch, D. J., Gazzinelli, A., \u0026amp; King, C. H. (2017). Decline in infection-related morbidities following drug-mediated reductions in the intensity of Schistosoma infection: A systematic review and meta-analysis. \u003cem\u003ePLOS Neglected Tropical Diseases\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(2), e0005372. https://doi.org/10.1371/journal.pntd.0005372\u003c/li\u003e\n\u003cli\u003eAula, O. P., McManus, D. P., Jones, M. K., \u0026amp; Gordon, C. A. (2021). Schistosomiasis with a Focus on Africa. \u003cem\u003eTropical Medicine and Infectious Disease\u003c/em\u003e, \u003cem\u003e6\u003c/em\u003e(3), 109. https://doi.org/10.3390/tropicalmed6030109\u003c/li\u003e\n\u003cli\u003eBetson, M., Sousa-Figueiredo, J. C., Kabatereine, N. B., \u0026amp; Stothard, J. R. (2012). 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(2022). \u003cem\u003eWHO guideline on control and elimination of human schistosomiasis\u003c/em\u003e. https://www.who.int/publications-detail-redirect/9789240041608\u003c/li\u003e\n\u003cli\u003eWiegand, R. E., Secor, W. E., Fleming, F. M., French, M. D., King, C. H., Deol, A. K., Montgomery, S. P., Evans, D., Utzinger, J., Vounatsou, P., \u0026amp; Vlas, S. J. de. (2021). Associations between infection intensity categories and morbidity prevalence in school-age children are much stronger for Schistosoma haematobium than for S. mansoni. \u003cem\u003ePLOS Neglected Tropical Diseases\u003c/em\u003e, \u003cem\u003e15\u003c/em\u003e(5), e0009444. https://doi.org/10.1371/journal.pntd.0009444\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"tropical-medicine-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tmah","sideBox":"Learn more about [Tropical Medicine and Health](https://tropmedhealth.biomedcentral.com/)","snPcode":"41182","submissionUrl":"https://submission.springernature.com/new-submission/41182/3","title":"Tropical Medicine and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7142467/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7142467/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFecal occult blood (FOB) is a reliable indicator of bowel morbidity, yet its utility in the context of intestinal schistosomiasis remains inadequately characterized. To address this gap, we conducted a pre-post intervention study to evaluate the potential of FOB as a surrogate marker of \u003cem\u003eSchistosoma mansoni\u003c/em\u003e-induced intestinal morbidity among preschool-aged (3\u0026ndash;5 years) and school-aged (9\u0026ndash;14 years) children in the Mbita Health Demographic Surveillance System, located along the shores and islands of Lake Victoria, Suba North sub-county, western Kenya. A total of 611 children from 10 primary schools were screened for \u003cem\u003eS. mansoni\u003c/em\u003e infection prior to praziquantel (PZQ) treatment, and 584 were re-evaluated six weeks post-treatment. In addition to \u003cem\u003eS. mansoni\u003c/em\u003e parasitological examination, FOB testing, malaria diagnosis, point-of-care hemoglobin measurement, and assessment of soil-transmitted helminth infections were performed both before and after treatment. Associations between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB positivity were analyzed using Pearson\u0026rsquo;s chi-square test and logistic regression. \u003cem\u003eS. mansoni\u003c/em\u003e infection prevalence was high overall, particularly among SAC (77.4%) compared to PSAC (66.5%). Prior to treatment, over 75% of infected children were FOB-positive. Significant reductions in both \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB positivity were observed six weeks after PZQ treatment (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01). Notably, PSAC residing on islands exhibited a higher likelihood of FOB positivity than those on the mainland. Our findings demonstrate a significant association between \u003cem\u003eS. mansoni\u003c/em\u003e infection and FOB positivity. These results suggest that FOB testing may serve as a practical and scalable tool to monitor treatment-associated reductions in intestinal morbidity due to \u003cem\u003eS. mansoni\u003c/em\u003e in endemic settings.\u003c/p\u003e","manuscriptTitle":"Association between Schistosoma mansoni infection and fecal occult blood in schoolchildren in Mbita, Suba North Sub-County, western Kenya","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-01 10:54:54","doi":"10.21203/rs.3.rs-7142467/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-16T12:06:06+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-10T13:20:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"311839109992564571748827782360399876100","date":"2025-08-04T08:07:58+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-31T17:58:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"7973476327156804151428368305008071593","date":"2025-07-31T12:48:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"131890342147093574211198082184517353199","date":"2025-07-30T13:27:30+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-29T09:12:01+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-29T07:00:21+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-29T06:59:59+00:00","index":"","fulltext":""},{"type":"submitted","content":"Tropical Medicine and Health","date":"2025-07-16T17:36:50+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"tropical-medicine-and-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tmah","sideBox":"Learn more about [Tropical Medicine and Health](https://tropmedhealth.biomedcentral.com/)","snPcode":"41182","submissionUrl":"https://submission.springernature.com/new-submission/41182/3","title":"Tropical Medicine and Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"76edd632-928c-48f0-b56e-61f0260d59fd","owner":[],"postedDate":"August 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-02T16:06:23+00:00","versionOfRecord":{"articleIdentity":"rs-7142467","link":"https://doi.org/10.1186/s41182-025-00814-5","journal":{"identity":"tropical-medicine-and-health","isVorOnly":false,"title":"Tropical Medicine and Health"},"publishedOn":"2026-01-26 15:58:54","publishedOnDateReadable":"January 26th, 2026"},"versionCreatedAt":"2025-08-01 10:54:54","video":"","vorDoi":"10.1186/s41182-025-00814-5","vorDoiUrl":"https://doi.org/10.1186/s41182-025-00814-5","workflowStages":[]},"version":"v1","identity":"rs-7142467","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7142467","identity":"rs-7142467","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}