Modeling potential risk areas of orthohantavirus transmission in northwestern Argentina using ecological niche approach

Abstract

Background Hantavirus Pulmonary Syndrome (HPS) is a rodent-borne zoonosis in the Americas, with up to 50% mortality rates. In Argentina, the northwestern endemic area (NWA), presents half of the annually notified-HPS cases in the country, transmitted by at least three rodent species recognized as reservoirs of orthohantavirus. The potential distribution of reservoir species based on ecological niche models (ENM) can be a useful tool to establish risk areas for zoonotic diseases. Our main aim was to generate an orthohantavirus risk map transmission based on ENM of the reservoir species in NWA, compare this map with the distribution of HPS cases and explore the possible effect of climatic and environmental variables on the spatial variation of the infection risk. Methods Using reservoir geographic occurrence data, climatic/environmental variables and the maximum entropy method, we created models of potential geographic distribution for each reservoir in NWA. We explored the overlap of the HPS cases with the risk map and the deforestation distribution. Then, we calculated the human population at risk using a census radius layer and a comparison of the latitudinal variation of environmental variables with the distribution of HPS risk. Results We obtained a single best model for each reservoir. The temperature, rainfall and vegetation cover contributed the most to the models. In total, 945 HPS cases were recorded, of which 97,85% of them were in the highest risk areas. We estimated that 18% of the NWA population was at risk and 78% of the cases occurred less than 10 km from deforestation. The highest niche overlap was between Calomys fecundus and Oligoryzomys chacoensis. Conclusions We are advancing with the identification of potential risk areas for HPS transmission and environmental and climatic factors that determine the distribution of the reservoirs and orthohantavirus transmission in NWA. This can be used by public health authorities as a tool to generate preventive and control measures for HPS in NWA.