Background

In sub-Saharan Africa, renal abnormalities are a major public health concern, especially in children living in Schistosoma haematobium endemic areas. However, there is a dearth of data on renal abnormalities among children living in Schistosoma mansoni endemic areas. The objective of the study was to assess the prevalence of renal abnormalities among school children in a Schistosoma mansoni endemic community in Northwestern Tanzania.

Methods

A cross-sectional study was conducted between January and March 2017 among school children aged 6–13 years, attending three primary schools located along the shoreline of Lake Victoria. A single urine sample was collected from each child and screened for S. mansoni using circulating cathodic antigen and for S. haematobium eggs using a urine filtration technique. A urine dipstick was used to screen for urine protein levels, creatinine levels, microalbuminuria, and red blood cells. Venous blood was obtained for estimation of creatinine level and for malaria diagnosis. The primary outcomes were the prevalence of renal abnormalities, defined by the presence of low estimated glomerular filtration rate (eGFR), proteinuria or microalbuminuria, and hematuria in urine.

Results

Of 507 children included in the final analysis, 49.9% (253/507) were male with a mean age of 8.51 ± 1.3 years. Overall, 64.0% (326/507) of the children were infected with S. mansoni, and 1.6% (8/507) of the children were infected with S. haematobium. A total of 71 (14%) of the children had proteinuria, 37 (7.3%) had hematuria, and 8 (1.6%) had a low estimated glomerular filtration rate (eGFR). Overall prevalence of renal abnormalities was 22.9%. Renal abnormalities (proteinuria) were associated with S. mansoni infection (OR = 4.9, 95% CI 2.1–11.2, p < 0.001) and having red blood cells in urine (OR = 5.3, 95% CI 2.5–11.2, p < 0.001).

Conclusion

Twenty-two percent of school children who participated in this study had renal abnormalities associated with S. mansoni infection. Given the high prevalence of S. mansoni, longitudinal epidemiological surveillance is warranted to measure the burden of renal abnormalities and assess the impact of the praziquantel treatment on these abnormalities.