Burden and risk factors of snakebite in Mopeia, Mozambique: Leveraging larger malaria trials to generate data of this neglected tropical disease

BackgroundSnakebite is a neglected disease that disproportionally affects the rural poor. There is a dearth of evidence regarding incidence and risk factors in snakebite-endemic countries. Without this basic data, it will be impossible to achieve the target of a 50% reduction of snakebite morbidity and mortality by 2030 as set by the World Health Organization. MethodsThis was a descriptive analysis nested in a 2021 community-based demographic survey of over 70,000 individuals conducted in Mopeia, Mozambique, in preparation for a cluster randomized trial to test an intervention for malaria. We describe the incidence rate, demographics, socioeconomic indicators and outcomes of snakebite in this population. FindingsWe found the incidence of self-reported snakebite in Mopeia to be 393 bites per 100,000 person-years at risk, with 2% of households affected in the preceding 12 months. Whilst no fatalities were recorded, over 3,000 days of work or school days were lost with an individual household economic impact higher than that of uncomplicated malaria. 1 in 6 of those affected did not fully recover at the time of the study. We found significant relationships between age older than 15, use of firewood for household fuel, and animal possession with snakebite. ConclusionsThis study exposes higher than expected incidence and burden of snakebite in rural Mozambique. Whilst snakebite elimination in Mozambique seems unattainable today, it remains a preventable disease with manageable sequelae. We have shown that snakebite research is particularly easy to nest in larger studies, making this a practical and cost-effective way of estimating its incidence. Author summarySnakebite is a neglected disease with a dearth of data and research funding. This study aimed to quantify the burden and identify risk factors of snakebite in a rural district in Mozambique by nesting snakebite-specific questions into a demographic survey conducted in preparation for a malaria cluster-randomized trial.We have shown that nesting has the potential to undo the neglect of snakebite research, providing valuable results for local decision makers and aid further research. Piggy-backing onto a large well-resourced trial enabled us to reveal the burden and identify risk factors of snakebite with minimal disruption or expense to the parent trial team or participants. This method can encourage the global health community to transition into a more horizontal research approach.We report an incidence close to 400 snakebite per 100,000 population per year in Mopeia leading to the loss of over 3,000 days of work/school. The median economic burden of snakebite per household was of US$ 17, making if almost 5-fold the cost of uncomplicated malaria cases. Although most bites occurred in those aged 20 to 25, the rate of bites per 1,000 population is much higher in those adults older than 64, this finding is also coupled with a lower recovery rate in the older age. We found no clear risk factor associated with place of bite and season.