Organophosphate poisoning temporal trends and spatial distribution, Uganda, 2017─2022

Abstract

Abstract Introduction: Organophosphates (OP) are toxic chemical agents used as agricultural pesticides and insecticides and are one of the commonest agents of poisoning worldwide, responsible for > 3,000,000 poisonings and 300,000 deaths globally per year. As a country with an agriculture-based economy, Uganda has widespread use of pesticides, creating an elevated risk for OP poisoning. We assessed the distribution and temporal and spatial trends of OP poisoning admissions in Uganda during 2017─2022 to guide control and prevention interventions. Methods We analysed OP poisoning surveillance data from the District Health Information System version 2 (DHIS2). As per DHIS2, OP poisoning admissions were defined as a hospital stay due to suspected OP poisoning while deaths were defined as inpatient deaths with OP poisoning listed as the cause of death. We calculated annual incidence of OP poisoning admissions per 100,000 population and case-fatality rates per patient admitted with OP at national, regional, and health facility levels. We used the Mann-Kendall (MK) test to determine the strength and direction of the trend. Results A total of 37,883 (average: 6,314 per year) OP admissions and 1,599 (average: 267 per year) deaths were reported (case-fatality rate [CFR] = 4.2%) during 2017─2020. Males (incidence = 18/100,000), children < 5 years (incidence = 20/100,000), and residents of Ankole Region (incidence = 26/100,000) were the most affected. CFRs increased with the increasing healthcare level of the admitting health facility. The incidence of OP declined by over 3-fold over the study period (MK=-13, p = 0.02). Kiruhura and Bukwo Districts had consistently high incidences (> 50/100,000) throughout the study period. Conclusion There was a significant reduction in incidence of OP poisoning in Uganda during 2017─2020. Males, children < 5 years, and residents in Ankole Region were the most affected. Strengthening sensitization among agricultural and livestock farming communities about the risks of pesticide poisoning and building capacity of health workers and equipping lower-level health facilities to effectively manage medical emergencies including OP poisoning could reduce the OP burden and mortality in Uganda.