In the journal PeerJ, 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. 

Using surveillance data, study authors attempted to predict the risk of plague across the western U.S. 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. 

RELATED: Second Plague Death Confirmed in Colorado

Areas of high risk were predicted in central Colorado, north-central New Mexico, and southwestern and northeastern California. The presence of P. maniculatus, mean precipitation during the driest and wettest quarters, altitude, and distance to artificial surfaces all affected the risk of plague.

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.

For more information visit