High Plague Risk Areas Identified in Western United States

Researchers have mapped out areas in the western United States with high probability of plague based on reports of plague occurrences in sylvan and domestic animal hosts.

Central Colorado, north-central New Mexico, and southwestern and northeastern California are areas in the United States with a higher probability of plague, according to an analysis of data from the International Society of Infectious Diseases that was published in PeerJ.

Using surveillance data, the study researchers attempted to predict the risk of plague across the western United States by modeling the ecologic niche between January 2000 and August 2015. 

A total of 66 reports of confirmed geolocated infection with Yersinia pestis were collected by the International Society of Infectious Diseases. 

The team utilized a Maxent machine learning algorithm to predict the niche based on climate, altitude, land cover, and the presence of Peromyscus maniculatus. The mapped areas as a result indicate the highest potential for human exposure to plague bacteria. 

Study findings may help “public health agencies target specific areas for enhanced plague surveillance within areas and counties predicted to be at high risk, as well as by other research teams to direct the sampling of local wildlife populations for the identification of Yersinia pestis,” added Michael Walsh, PhD, MPH, assistant professor in the Department of Epidemiology and Biostatistics in the School of Public Health at SUNY Downstate.


1. Walsh M, Haseeb MA. Modeling the ecologic niche of plague in sylvan and domestic animal hosts to delineate sources of human exposure in the western United States.PeerJ. 2015;doi:10.7717/peerj.1493.

This article originally appeared on MPR