Epidemiology of snake envenomation from Mato Grosso do Sul, Brazil

Snake envenomation is considered a public health problem in tropical countries, where they occur in a high incidence. The present study reports the snake envenomation that occurred in Mato Grosso do Sul state (Brazil) between 2007 and 2017. Epidemiological data were obtained from the online platform of the Notification Disease Information System and were analyzed according to biome. A total of 5568 cases of snake envenomations were recorded during the study period, where the highest frequency was registered between October and April. The majority of envenomations occurred in working-age males (20 to 39 years), caused mainly by Bothrops snakes, and the duration of care after the envenomation in most cases took three hours. The municipalities that showed the highest snake envenomations case per 100,000 inhabitants presents low population density, and have their economy based on agricultural activity, which is a risk factor to snake envenomations. To the Mato Grosso do Sul state, the total number of snake envenomations had a positive relationship with the size of the municipality. Since this, larger areas usually have a mosaic of environments, which may harbor higher richness and abundance of snakes, and can cause more snake encounters with the population, resulting in more snake envenomations. Author summaryBrazil is the country in South America with the most reported snake envenomations, however, the incidence of snake envenomations is not equal throughout the country. In most cases, the occurrence of snake envenomations is related to environmental factors (e.g., climate) and the increase of human activity in fieldwork. Besides those factors, problems in urban infrastructure, municipality size, or population size are also variables that can influence the number of snake envenomations in a region. The authors found that in the Mato Grosso do Sul state, Brazil, the number of snake envenomations is low when compared with Mato Grosso and Goias states, and the national average. Despite this, snake envenomations in Mato Grosso do Sul confirmed trends observed in other Brazilian regions, happening mainly in October and April. Most of the envenomations occurred in males by Bothrops snakes and with an attendance time of 3 hours. Also, the authors found that there is a relationship between municipality areas with the number of snake envenomations. Seen this, municipalities with larger areas usually have a mosaic of environments, which may harbor higher richness and abundance of snakes, and can cause more snake encounters with the population, resulting in more snake envenomations.