Adolescents and young adults excluded from preventive chemotherapy for schistosomiasis control in Northern Tanzania: are they at risk and reservoirs of infection? Prevalence and determinants of transmission in Northern Tanzania

OBJECTIVE: To investigate the magnitude of urogenital schistosomiasis and determinants of transmission among adolescents and young adults in Itilima district, Simiyu region, Northern Tanzania. METHODS: A quantitative cross-sectional study was carried out using probability sampling strategies to select 433 secondary school students from five schools among the five wards of Itilima district, an area endemic for urogenital schistosomiasis. A self-administered structured questionnaire was used to gather data on determinants, and urine samples were examined for macrohaematuria and the presence of Schistosoma haematobium using the standard urine filtration technique. Data analysis was performed using descriptive statistics, Chi-squared test and logistic regression. RESULTS: The overall prevalence rates of S. haematobium infection and macrohaematuria among adolescents and young adults were 15.9% and 3%, respectively, with the majority of individuals being lightly infected (85.5%). The determinants for urogenital schistosomiasis among the adolescents and young adults in Itilima district were: being in Form I [adjusted odds ratio (aOR) 2.42, 95% confidence interval (CI) 1.16–11.8; P=0.018]; being resident in Sasago ward (aOR 5.57, 95% CI 1.98–15.67; P=0.001) or Budalabujiga ward (aOR 2.99, 95% CI 1.04–8.56; P=0.042); having positive attitudes towards urogenital schistosomiasis (aOR 3.14, 95% CI 1.27–7.72; P=0.013); swimming in rivers (aOR 1.92, 95% CI 1.06–3.50; P=0.032); and urinating in water bodies (aOR 1.68, 95% CI 1.05–2.69; P=0.032). CONCLUSIONS: Urogenital schistosomiasis is prevalent among adolescents and young adults, and serves as a reservoir for transmission of S. haematobium. Preventive chemotherapy campaigns should be extended to adolescents and young adults, and integrated with regular screening, health education and an adequate water supply.