Predicting zoonotic spillovers under future environmental stressors

A zoonotic spillover is when an infectious disease moves from its animal source or reservoir via a vector, to humans. Examples include Ebola, SARS, AIDS, and, the focus of this study, hemorrhagic fever caused by Lassa fever virus (LAS). Integrating global environment stressors, researchers assessed the impact of climate change, population growth and land use on future emergence and spread of LAS. By use of confirmed disease cases and GBIF mediated occurrences of the Lassa virus reservoir, the natal multimammate rat (Mastomys natalensis), the researchers created ecological niche models examining relationships with a variety of environmental variables. The find significant associations between LAS outbreak and reservoir presence, annual precipitation, population density and rice yields. The models predict a doubling of spillover events under future scenarios. The methodology described in the study can be incorporated in epidemiological disease models to create a powerful framework for predicting spillovers of zoonotic diseases.