Testing has confirmed that six free-ranging white-tailed deer from four Michigan counties have died from epizootic hemorrhagic disease.
Another 150 likely cases have been reported over the past 15 days, the Michigan Department of Natural Resources said Tuesday.
The viral diseaseis transmitted by a type of biting fly called a midge and can cause internal bleeding and fluid accumulation. In severe forms of the disease, deer lose their appetite and fear of humans, grow progressively weaker, salivate excessively and finally become unconscious.
Infected deer often seek water to lower their body temperature and rehydrate, and then are found sick or dead along or in bodies of water. There is no known effective treatment for the virus in wild deer populations.
The disease also is found in mule deer and elk. There is no evidence that humans can contract the virus, the DNR said.
Three of the fatal cases were identified in Oakland County. Macomb, St. Clair and Shiawassee counties each had one case.
Deer deaths in Michigan from epizootic hemorrhagic disease have occurred on and off since 2006. More than 14,000 deer are estimated to have died during a 2012 outbreak.
No cases were confirmed in 2014 or 2015, and few have been reported since 2015, the DNR said.
Alabama, Mississippi and other states also are reporting deer sick and dying this year from the disease.