Prevalence and risk factors associated with Schistosoma haematobium infection among school pupils in an area receiving annual mass drug administration with praziquantel: a case study of Morogoro municipality, Tanzania

Abstract

Background: There is a scarcity of accurate data on Schistosoma haematobium infection on country-specific prevalence despite mass drug administration over the years. Prevalence estimates for the number of people infected and the number at risk of infection must still be made based on calculations of limited prevalence survey data at the country level. This study aimed to fill in the gap of data on prevalence in an urban setting that has been receiving mass drug administration with praziquantel and determine the risk factors associated with S. haematobium infection among school pupils.

Method: A cross-sectional, stage-wise random sampling survey of S. haematobium infection, factors influencing its transmission and mass drug administration with praziquantel were studied among primary school pupils in Morogoro Municipality. A semi-structured questionnaire was used to collect data on risk factors, and urine samples were collected from pupils and examined for S. haematobium eggs and macro and microhematuria. Results were analyzed using SPSS version 12.0.

Result: The overall prevalence rate of S. haematobium infection was found to be 32.5% (95% CI, -3.1- 5.6%) in the ten schools that were sampled. It was observed that 228/884 (25.8%) of the pupils had low infection intensity and 82/884 (9.3%) had high infection intensity. The total number of pupils that had S. haematobium infection was 287, where 116 (40.42%) of them had micro-hematuria. The proportion of students that did receive praziquantel in the last general distribution was found to be 14.3% while 25.8% of the students had low infection intensity and 9.3% had high infection intensity across all age groups. Whereby 3.96% of pupils that received praziquantel in the last general administration also had S. haematobium infection (OR 0.77, 95% CI 0.5-1.2) The risk factors associated with S. haematobium infection were playing, bathing, fishing in rivers and helping parents work in rice fields (p –value<0.001).

Conclusion: The prevalence and intensity are high enough to cause re-infection. Still, more effort is needed to enforce mass praziquantel administration among primary school pupils, alternative water sources for recreational activities, provision of proper latrines and further studies needed to explore the risk factors.