BATTLE CREEK, Mich. (FOX 2) - Tests confirm two Mexican gray wolf pups at southern Michigan zoo have died of a rare mosquito-borne virus as health officials work to curb the spread of the virus in people and animals.
Binder Park Zoo in Battle Creek says results received this week confirm the pups that died in early September were killed by Eastern equine encephalitis.
The zoo says the pups were born on June 14 to a breeding pair of Mexican gray wolves that's part of a Species Survival Plan recommended through the Association of Zoos and Aquariums. The surviving wolf pup and both parents appear healthy and are being monitored closely by the veterinarian and animal care staff.
Other zoo animals, such as zebras, Przewalski's horses and ostriches, are vaccinated annually at Binder Park Zoo against EEE, but there's no approved vaccine for canines right now.
The state Department of Health and Human Services reports EEE has been confirmed in humans or animals in at least 12 Michigan counties. Three people in southwestern Michigan have died.
The counties listed as high risk include: Barry, Berrien, Calhoun, Cass, Genesee, Jackson, Kalamazoo, Lapeer, Montcalm, Newaygo, St. Joseph and Van Buren.
EEE has a 33 percent fatality rate for those who become sick from the disease. For kids under 15 years old and adults over the age of 50, the fatality rate can rise as high as 50 percent.
Symptoms exhibited by the disease aren't very obvious. Of the 4 to 5 percent of people who do contract the disease and show symptoms, they include chills, fever, weakness, muscle and joint pain and can last up to two weeks. However, for the 1 percent of people who do show serious symptoms, they include neurologic issues like inflammation of the brain.
EEE is typically a serious problem for horses, which is why a vaccine was developed if they contract the disease. No vaccine exists for humans.
People are urged to guard against mosquito bites. The department is encouraging officials in affected counties to consider postponing, rescheduling or cancelling outdoor activities including sports occurring at or after dusk until there's a hard frost.
Aerial spraying is being considered.
Fox 2 reported on this story from Southfield, Mich.
The Associated Press contributed to this report