Unvaccinated horses, weather were factors in outbreaks
The prolonged hot and wet summer in some Midwestern and Southeastern states this year created conditions favorable for outbreaks of eastern equine encephalitis. As of late September, the Department of Agriculture’s National Animal Health Surveillance System reported 180 laboratory-confirmed cases of EEE in horses.
Though the national total may come in below the typical number of cases seen each year—the mean number of equine EEE cases seen annually from 2003-2009 is 283—some states have been harder hit than others.
In all, Michigan has had 45 confirmed equine cases of EEE. The southwest portion of the state has long been an area associated with cases of arbovirus infection, particularly a nine-county area that accounted for about 90 percent of the EEE cases in Michigan this year. The area has a lot of surface water and a soil type that provides a favorable pH for mosquitoes. Read more..
