Maine has recorded its first case of West Nile virus this season, state officials announced Monday.
The disease, transmitted through the bite of an infected mosquito, was confirmed at a mosquito testing site in the York County town of Alfred, according to the Maine Center for Disease Control and Prevention and the Maine Department of Agriculture, Conservation and Forestry.
West Nile made a comeback nationally in 2012, infecting more than 5,600 people and killing 286. Maine confirmed its first human case of the disease last October in a Cumberland County man who later recovered.
Mosquitoes pick up the virus from biting infected birds and then transmit it to people.
Most people infected with West Nile don’t show any symptoms. About one in five gets sick with a fever, body aches, vomiting and joint pain that can last from a few days to several weeks. Symptoms typically appear between three and 14 days after a bite from an infected mosquito.
In the rare severe cases, the virus causes neurological problems such as brain swelling, which can lead to confusion, coma, seizures and permanent damage.
State officials also announced Monday that an additional 13 testing pools in Alfred, Kittery and York have tested positive for another, rarer mosquito-borne disease called Eastern equine encephalitis, bringing the year’s total to 21.
Maine CDC attributed the death of a pheasant in York County to EEE. Last week, two horses died from the infection, one in Oxford County and another in York County. In 2012, a flock of 30 farm-raised pheasants in Lebanon died from EEE.
The EEE virus, which also is transmitted through the bite of an infected mosquito, can cause serious illness in humans, large animals including horses and some species of birds. The virus sometimes leads to encephalitis, or inflammation of the brain, resulting in death in one out of every three human cases.
Last fall, a Vermont man died of EEE.
EEE has not been detected in humans in Maine. It reappeared in the state after killing 15 horses in 2009.
“The fact that we now have pools testing positive for EEE and WNV only increases the need for prevention,” Dr. Stephen Sears, state epidemiologist, said in a press release.
Assistant State Veterinarian Beth McEvoy noted in the release that the EEE vaccination takes time to provide protection to horses, so use of repellants and protective sheets and blankets is recommended along with vaccination.
There is no human vaccine against EEE or West Nile virus.
Maine CDC recommends the following steps to protect against EEE, West Nile virus and other mosquito-borne illnesses:
— Use an Environmental Protection Agency-approved repellent when outdoors, especially around dawn and dusk. Always follow the instructions on the product’s label.
— Wear protective clothing when outdoors, including long-sleeved shirts, pants and socks.
— Keep window and door screens down to keep mosquitoes out of the home.
— Limit time outdoors at dawn and dusk, when many species of mosquitoes are most active.
— Remove containers holding water in and around the home, which can attract mosquitoes.