Molecular characterization of urogenital schistosomiasis in Shinyanga and Misungwi districts, North-Western Tanzania

Abstract

Background: Schistosomiasis is a major parasitic disease, second only to malaria in its global socio-economic impact. In regions like Tanzania, praziquantel (PZQ) is the primary treatment. Recent studies in West Africa suggest the presence of Schistosoma hybrids, potentially influencing the disease's epidemiology. Understanding the prevalence of urogenital schistosomiasis and schistosome hybrids is essential for improving targeted interventions and disease management strategies. This study aimed to investigate the effect of praziquantel on urogenital schistosomiasis prevalence and assess the molecular epidemiology of both Schistosoma haematobium and its hybrid with Schistosoma bovis.

Methods: In a cross-sectional study, urine samples from 1,910 individuals in southern Lake Victoria villages were tested for S. haematobium eggs using urine filtration and microscopy. Genetic analysis of individual miracidia from egg-positive samples was conducted using Rapid Diagnostic Multiplex PCR.

Results: Pre-treatment, S. haematobium prevalence was 6.4%, with significant variation across villages. Post-treatment prevalence dropped to 0.3%, indicating a praziquantel cure rate above 90%. Hybrid infections of S. haematobium and S. bovis were detected in one village at a prevalence of 3.5%, all successfully treated with praziquantel. These results highlight praziquantel’s effectiveness against both S. haematobium and hybrid infections.

Conclusion: Praziquantel treatment resulted in a significant reduction in S. haematobium prevalence and the complete elimination of S. haematobium-S. bovis hybrids, indicating successful disease burden reduction. Further studies are needed to evaluate the long-term effectiveness and broader implications of this intervention.