Repeated biannual cross-sectional surveys in primary schools set baseline seasonal and spatial surveillance for malaria and schistosomiasis in the Shire Valley Transformation Programme (SVTP), Malawi

Control of malaria and schistosomiasis among school children poses a key public health challenge in Chikwawa District, Malawi. Furthermore, anticipated environmental changes from the Shire Valley Transformation Programme (SVTP), a large-scale irrigation scheme, are expected to both alter transmission of malaria and schistosomiasis. To later inform future disease surveillance and appropriate control interventions, our study sought to establish comprehensive seasonal and spatial baseline epidemiological data. Four cross-sectional surveys were undertaken in 21 primary schools, covering two wet and two dry seasons. A total of 4176 children aged 7-13 years were examined using rapid diagnostic tests for malaria, urine reagent strips with egg-filtration microscopy for urogenital schistosomiasis, and urine-Circulating Cathodic Antigen (CCA) dipsticks for intestinal schistosomiasis. The overall prevalence was 10.8% (95% CI: 9.8-11.7%) for malaria, 36.5% (95% CI: 35.1-38.0%) for urogenital schistosomiasis, and 1.9% (95% CI: 1.5-2.4%) for intestinal schistosomiasis. Co-infection prevalence of malaria and urogenital schistosomiasis was 5.2% (95% CI: 4.5-5.9%). Macrohematuria was at 5.5% (95% CI: 4.8-6.2%) while microhematuria was at 26.2% (95% CI: 24.9-27.6%). Seasonal fluctuations were noted for malaria, whereas schistosomiasis was limited, although both diseases exhibited strong spatial heterogeneity. Alarmingly, malaria exceeded 25% and urogenital schistosomiasis surpassed 50% in certain schools, thus clearly demonstrating currently unmet public health needs. These are set to become further exacerbated by forthcoming SVTP-driven environmental change; hence, we provide critical evidence to guide the Malawi Ministry of Health in strengthening surveillance and preparing integrated disease control.