Mayaro virus distribution in South America.

Mayaro virus (MAYV) is a pathogen endemic to South America and some Caribbean islands, with reports of occasional outbreaks. However, its current distribution and high-risk areas are little known. We conducted a modelling study to determine the areas with highest prevalence of MAYV occurrence in South America, based on confirmed cases and serological detection over the last 20 years and socio-environmental variables. We performed our analysis using Maxent software, a machine learning algorithm used for species distribution modeling. Our results showed that the occurrence of MAYV is mainly associated with the biome type, population density, annual rainfall, annual vapor rate, and elevation. Among biome types, the one most related to the occurrence of MAYV is Cerrado, probably related to the lifecycle of the Haemagogus vector and human population concentrations. According to our modelling, there is high yet undetectable MAYV concentration in the central region of Brazil and west-coastal region of the continent. A change in virus dispersion patterns was observed. The virus was previously predominantly in forests but now occupied rural areas and was becoming increasingly urbanized, which is increases the risk of outbreaks. Our results will serve to identify priority areas in the development of preventive actions and structuring of epidemiological surveillance.