Raccoon rabies has been endemic in New York state-from 1990 to 2004, 74% of confirmed rabies cases in the state occurred in raccoons. This study evaluated the geographic epidemiology of endemic raccoon rabies. The authors analyzed 4448 cases in terrestrial mammals across the New York geographic area, and specifically evaluated areas without vaccine exposure (oral rabies vaccines in food baits). Geographic variables were correlated with the presence of rabies cases, including year, county, ecoregion, geographic latitude, tract proportion, presence of lakes and rivers, and human population density. Approximately 59% of all census tracts reported rabies cases during the time of the study. Most of the study area consisted of forested land. Wetland areas and areas of higher elevation had fewer identified rabies cases, and areas of low residence and those with fewer roads had more identified rabies cases. This geographically based study generated risk estimates for rabies at the census-tract level. The authors created a model to implement cost-efficient bait distribution plans. They suggested that oral rabies vaccine baits should be preferentially dispersed to higher-risk areas for geographically based baiting and humane trapping.

COMMENTARY: This very interesting epidemiologic study has practical implications. The study methods exemplified those used in infectious disease epidemiology, and the creation of a model allowed for effective interventions in disease prevention and containment. The findings are directly relevant to the veterinary field because rabies is an important infectious disease with substantial zoonotic potential and high fatality.

Factors associated with endemic raccoon (Procyon lotor) rabies in terrestrial mammals in New York state, USA. Recuenco S, Eidson M, Cherry B, et al. PREV VET MED 86:30-42, 2008