Snakebite incidence in rural sub-Saharan Africa might be severely underestimated.

Snakebites in sub-Saharan Africa account for 20,000 to 32,000 annual deaths. But since most data is retrieved from hospital or incomplete central databases, and many victims do not seek hospital treatment or prefer traditional remedies, the current numbers are likely underestimated. In order to reduce snakebite incidence by 50% by 2030 as targeted by World Health Organization, it is crucial to accurately quantify and understand the current rates of snakebite incidence, which can only be reliably measured through household surveys. In this study, we interviewed 1037 households in nine communities in Cabo Delgado, northern Mozambique. Our aim was to quantify true snakebite incidence and under-reporting, by comparing the total number of snakebites reported to our team during household surveys with the subset of reports that reached health centers. We additionally quantified snakebite incidence in terms of species, location of the attack, type of treatment, season, and gender of the victims. These data allow us to propose conservative extrapolations of snakebite incidence and mortality for the province of Cabo Delgado and for Mozambique. Of all snakebites reported in the surveys (N = 296), most incidents were treated exclusively by traditional doctors (N = 174; 59%) and 25% were not seen by any doctor. Most bites occurred on farms and during the rainy season. Using a conservative estimation where we assume our results to be extrapolatable for the whole of rural Mozambique, but considering snakebites in urban areas to be inexistent, we propose that in Cabo Delgado, every year at least 6124 people are victims of snakebites, of which at least 791 result in deaths. In Mozambique, we extrapolated that every year at least 69,261 people are victims of snakebite, of which at least 8950 result in death (one in eight snakebites is fatal). Our estimates are the first for Mozambique based on data retrieved in the country, and despite being an underestimation they increase snakebite incidence levels ten-fold and the number of deaths by 30-fold. Urgent and widespread surveys are needed to further assess the full extent of snakebites in sub-Saharan Africa, explore regional patterns and develop mitigation plans.

Species perceived to be dangerous are more likely to have distinctive local names.

BACKGROUND: Species with direct uses, such as sources of food, shelter, building material and medicine tend to have more specific local names. But could the same apply for species that people fear? METHODS: To address this question, here we explore the behavior and perception of species diversity and dangerousness through a survey of 1037 households in nine villages in Cabo Delgado, northern Mozambique. We compare people's knowledge of snakes with that of lizards and amphibians. RESULTS: We find that northern Mozambicans know four to five times more local names for snakes than for lizards and frogs, despite the local species richness of snakes being comparable to the diversity of lizards and frogs. We further find that local knowledge was on par with the academic literature regarding snakebite symptoms. CONCLUSIONS: Our results suggest that fear can increase the level of specificity in naming species among indigenous communities, which could lead to biases in the mapping and protection of species that include data from citizen reports.