Prevalence of Schistosoma mansoni, soil-transmitted helminths and intestinal protozoa in orphans and street children in Mwanza city, Northern Tanzania

BACKGROUND: Parasitic infections are highly prevalent in low-income environments worldwide. While orphans and street children represent a particularly vulnerable population group, they are often exempt from preventive interventions such as Mass Drug Administration. In part, this could be due to a lack of data showing the burden of disease in this group. This study aims to address this gap. METHODS: For this cross-sectional study, 144 orphans and 112 street children were screened for Schistosoma mansoni (S. mansoni), Schistosoma haematobium (S. haematobium), soil-transmitted helminths and intestinal protozoa using POC-CCA testing, urine filtration, and Kato-Katz technique. Nutritional status, water- and washing patterns were determined using a standardised questionnaire. Ultrasonography was performed to screen for organ abnormalities. RESULTS: The prevalence of S. mansoni determined by POC-CCA-test was 65.9% for orphans and 94.5% for street children. 19.2% of the orphans tested positive for S. mansoni in Kato Katz. Of the street children, 77.1% showed positive test results in Kato-Katz. Only 1.3% of the orphans stated in the questionnaire that they use the lake to wash, whereas 91.1% of the street children named the lake as at least one of their options for washing. Microscopy showed positive results for Giardia intestinalis (G. intestinalis) in 8.2% and for Entamoeba histolytica/dispar (E. histolytica/dispar) in 23% of orphans and 8.1% for G. intestinalis, and 23.8% for E. histolytica/dispar in street children. In the ultrasonography, we did not observe patterns that indicate severe periportal fibrosis. CONCLUSION: The results indicate a significantly higher rate of infections with S. mansoni in street children compared with orphans. This might be explained by the lack of access to adequate sanitation for street children as well as regular contact with the water of Lake Victoria. However, we did not find similar results concerning infection rates with protozoa. The study results show overall inadequate living conditions in this study population, which could be addressed by public health interventions.