Antivenom accessibility impacts mortality and severity of Brazilian snake 2 envenomation: a geospatial information systems analysis

BackgroundIn 2017, the World Health Organization declared the snakebite envenomation as a neglected tropical disease. Annually, snakebite envenomation causes approximately 400,000 permanent disabilities and 95,000 deaths worldwide. People with the greatest risk of envenomation lack access to adequate health care, including treatment with antivenom. We developed an analysis of accessibility to antivenom in Brazil in order to verify the impacts on mortality. Methods and FindingsInformation about number of accidents, deaths, antivenom, medical assistance, and species, were retrieved from the Brazilian Health Informatics Department (DATASUS) from 2010 to 2015 and analyzed using geostatistics to evaluate the association between snakebite accidents and mortality. An Spatial analysis using Global Morans I was performed in order to verify the presence of spatiality as an independent variable to the distribution of the accidents. In addition, we also tested three different analysis of regression using Ordinary Least Square (OLS), Spatial Error, and Geographically Weighed Regression (GWR), together with the information obtained from the DATASUS and sociodemographic indicators, to verify the spatial-temporal distribution of envenomation cases and time to reach the healthcare centers. The regression presenting the lowest Akaike Criterion Information (AIC), highest adjusted R2, and variables with p < 0.05 was selected to represent our model. Lastly, the accessibility index was performed using 2-step floating catchment area based on the amount of hospital beds and inhabitants. This study revealed 141,039 cases of snakebites, 598 deaths, and mortality rate of 3.13 per 1,000,000 inhabitants. Moreover, GWR presented the best fit (AIC = 55477.56; adjusted R2 = 0.55) and showed that illiteracy, income, percentage of urban population, percentage of antivenom, accessibility index for hospital beds with antivenom, proportion of cases with more than 3 hours to reach healthcare are correlated with the mortality rate by snakebite (p < 0.05). ConclusionThis study identified regions affected by snakebite and how the accessibility to antivenom treatment plays an important role in the mortality in Brazil. Public interventions can located to those most vulnerable regions in order to improve the accident outcome.