Trends of Coverage of Mass Drug Administration, Population at Risk and Reported Cases of Schistosomiasis and Soil-Transmitted Helminths, Uganda, 2013-2023

BackgroundUganda has a high burden of Neglected Tropical Diseases (NTDs), which particularly affect rural populations. Some NTDs are targeted for control/elimination using preventive chemotherapy administered annually or bi-annually to at-risk populations through mass drug administration (MDA). Schistosomiasis and soil-transmitted helminths (STHs) are two of these diseases. MDA for Schistosomiasis is given only to school-age children (SAC) and adults, whereas that for STHs is given only to SAC and pre-school-age children (pre-SAC). The MDA coverage target for both NTDs should be 75%. A decline in the size of the population at risk (PAR) and the number of cases are indicators of effective control/progress towards elimination. We describe the trends in the coverage of MDA and the outcomes of schistosomiasis and STHs.MethodsWe reviewed available data on MDA coverage, size of population at risk, and disease occurrence (case counts) for schistosomiasis and STHs from 2013 to 2023. We analysed the trends using the Mann Kendal test.ResultsFrom 2014 to 2022, there was an apparent increase in MDA coverage for schistosomiasis in both SAC (from 21 to 82%, p = 0.5) and adults (from 34 to 36%, p = 0.1); however, both trends were not significant. Similarly, for STHs, MDA coverage increased for both SAC (from 63 to 114%, p = 0.09) and pre-SAC (from 65 to 76%, p = 1.0); however, these trends were not significant. The PAR for schistosomiasis increased by 25% for SAC (2014: 4,777,189 vs 2022: 5,979,311, p = 0.0025) and by 60% for adults (2014: 4,436,444 vs 2022: 7,091,933, p = 0.03). For STHs, PAR increased by 19% for both SAC (2014:11,287,385 vs 2022:13,397,219, p = 0.03) and pre-SAC (2014: 5,279,025 vs 2022: 6,299,355, p = 0.047). From 2013 to 2023, there was a 62% reduction in reported cases of schistosomiasis (2013:6,518 vs. 2023:2501, p = 0.7) and a 52% reduction in reported cases of STHs (2013:2,457,021 vs. 2023:1,176,463, p = 0.5), but both trends were not significant. The increase in PAR indicates that transmission is spreading beyond previous extents despite ongoing MDA. Non-significant trends may be attributed to fluctuations across years, precluding a monotonic pattern., Nonetheless, the apparent changes can provide actionable insights to inform improvements in programmatic interventions.ConclusionsCurrent efforts to control schistosomiasis and STHs using MDA should be strengthened to achieve sustainable control. Strategies to improve and maintain MDA coverage for both NTDs to a target of 75% are crucial, while the rise in PAR and unabating case counts necessitate targeted interventions, including improved sanitation, health education, and vaccine development.