Assessing the risk of diseases with epidemic and pandemic potential in a changing world

Abstract

How do human activities contribute to the emergence of zoonotic diseases that can lead to epidemics and pandemics? Our analysis of common drivers of the World Health Organization's priority diseases suggests that climate conditions, including higher temperatures, higher annual precipitation levels, and water deficits, elevate the risk of disease outbreaks. In addition, land-use changes, human encroachment on forested areas, increased population and livestock density, and biodiversity loss contribute to this risk, with biodiversity loss showing a complex and nonlinear relationship. This study also presents a global risk map and an epidemic risk index that combines countries' specific risk with their capacities for preparing and responding to zoonotic threats.

Fig. 1.. Risk of the WHO priority diseases, bias adjusted.

The map displays the risk levels across different regions, with white areas indicating insufficient data for one or more predictor layers. The accompanying table provides a summary of the results, showing the percentage of land area and population [in millions (M)] falling within each risk category. The population estimate was calculated by averaging the population over the study period and summing it within each risk category.

Fig. 2.. Relationship between predictor variables and the risk of WHO priority diseases.

The plot illustrates the association between each predictor variable and the risk of WHO priority diseases, with uncertainty represented by the gray-shaded area. Note that all predictor variables were calculated at a spatial resolution of 30 km, using a grid-based approach.

Fig. 3.. Country-level epidemic risk index, adjusted for national capacities and capabilities to respond to zoonotic events at the animal-wildlife interface.

(A) Epidemic risk index matrix, categorized by region and is color coded, with each circle representing a country. The matrix combines maximum outbreak risk and epidemic risk, informed by C3 zoonotic event data and IHR C3 data on the human-animal health interface. (B) Distribution of countries across matrix categories and regions, also color coded, showing the number of countries in each category.