School-Based Epidemiology of Schistosoma haematobium Infection in Kharif District of Amran Governorate, North of Yemen: Need for Chemopreventive Strategy Revisiting.

Background: Urogenital schistosomiasis is a persistent public health problem in many rural areas of Yemen. Since 2014, Schistosoma haematobium epidemiology has not been assessed in Amran governorate, north of Yemen, where S. haematobium is known to be highly endemic. Therefore, this study determined the prevalence and risk factors associated with S. haematobium infection among schoolchildren in Kharif district of the governorate.

Methods: A cross-sectional survey was conducted among 529 schoolchildren aged 7 to 15 years in Kharif district. Data on children's demographics, clinical features, behaviors, and infection-related environmental factors were collected using a structured questionnaire. The urine filtration technique was used to detect and count S. haematobium eggs, and chemical reagent strips were used to detect microhematuria. The number of eggs per 10 mL of urine (EP10mL) was used to estimate the intensity of infection, which was classified as light (≤50 EP10mL) or heavy (>50 EP10mL). Multivariable binary logistic regression analysis was used to identify predictors of infection.

Results: Light-intensity S. haematobium infection was prevalent among 34.8% of schoolchildren in Kharif district, with a 95% confidence interval (CI) ranging from 30.7 to 38.8. Infection was significantly associated with microhematuria (P <0.001) and self-reported dysuria (P = 0.003). Family ownership of agricultural land was significantly associated with S. haematobium infection among schoolchildren [odds ratio (OR) = 1.8, 95% CI: 1.10-3.17; P = 0.030], which was further identified as an independent predictor of infection (adjusted OR = 2.2, 95% CI: 1.21-3.95; P = 0.010).

Conclusion: A considerable proportion of schoolchildren in Kharif district have light-intensity S. haematobium infections, mostly presenting with microhematuria and self-reported dysuria. The district's level of risk should be updated to moderate. Consequently, the chemopreventive strategy needs to be revisited to treat all school-age children biennially, regardless of enrollment status.