PORTLAND – A horse from the southern Maine town of Lebanon has become the first mammal in the state to die of Eastern equine encephalitis, according to health officials.

The recent death confirms the presence in Maine of the potentially fatal virus, which is carried by mosquitoes, said Dr. Dora Anne Mills, director of the state Bureau of Health.

“That means there has to be some positive, infected mosquitoes in the area that can bite and infect humans,” Mills said.

No human in Maine has ever tested positive for EEE, but two New Hampshire residents died from the disease this year and five others were infected by the virus.

Mills recommends that people living in southern Maine or along the New Hampshire border take extra precautions against mosquitoes. She advised that people wear long sleeves and pants and apply insect repellent, while noting that cold weather will halt mosquito activity.

State health inspectors planned to be at the Fryeburg Fair this weekend, putting up posters about EEE and preventive measures. People cannot contract EEE from horses and should not be discouraged from going to outdoor events such as the fair, Mills said.

Like West Nile virus, EEE can cause brain infection and encephalitis.

Two weeks ago, a dead bird found in Limington was the first to test positive for EEE in several years. But that was not as much a concern to public health officials.

“A dead bird, by itself, doesn’t really tell you much. It could have just flown in and died,” Mills said.

Eight other birds in Maine have tested positive for West Nile virus this summer. Six were in York County; the other two were in Cumberland and Androscoggin counties.