AUGUSTA, Maine — State veterinarian Don Hoenig confirmed Tuesday that five additional cases of Eastern equine encephalitis are suspected in Maine — four in horses and one in a llama.
Six cases of the deadly disease had been confirmed previously.
All of the 11 animals have been euthanized.
“We have an unprecedented, extraordinary outbreak like we have never seen before,” Hoenig said Tuesday evening.
The latest suspected cases were the llama reported in Trenton and horses reported in Newport, Jackson, Windsor and Unity.
Three of the horses and the llama are pending a confirmed diagnosis by state officials.
The horse in Unity that was euthanized by its owner does not have blood tests pending, but its symptoms indicated it had EEE.
“For the horses, it certainly sounds like they had signs consistent with EEE,” Hoenig said. He said the disease causes infected animals to go from mild symptoms to a coma state in 24 to 48 hours.
The disease is spread through mosquitoes. “That is why there are no travel restrictions or quarantines,” Hoenig said. “It is not contagious, and an infected horse is not a threat to humans.”
Infected mosquitoes, however, can infect humans.
After the first two horses — one in Troy and one in Thorndike — were confirmed for EEE in early August, state health officials became concerned. Other horses died in Stetson, Unity and Gorham.
“This is the farthest north EEE has ever been detected in this country,” Dr. Dora Anne Mills, director of the Maine Center for Disease Control and Prevention, told the Bangor Daily News on Aug. 31 of the Stetson case, before the Trenton case was suspected.
Mills urged Mainers to protect themselves against mosquitoes in order to avoid contracting the virus.
The horse deaths are “a strong red flag that the risk of EEE is much greater than we thought,” she said. “In the past, we’ve seen it later in the fall. What we’re concerned about now is that it is still very warm out and there are a lot of mosquitoes still biting.”
The only thing that will ultimately stop the spread of EEE in Maine is a series of killing frosts, Hoenig said. Mosquitoes become carriers of the virus only by first biting an infected bird — songbirds, pheasant and quail, primarily, he said.
“Our main fear,” Hoenig maintained, “is that this will spread to humans.”
There is no human vaccine against EEE, and no human case of EEE has ever been confirmed in Maine. Last October, however, a Massachusetts man died of EEE and he may have contracted it while vacationing in the Naples area. His was the first Massachusetts death from EEE in a human since 2005, when four cases were re-ported, two of them fatalities.
Mainers, especially those who live, go to school or spend time near wetland areas, should take extra precautions to protect themselves from exposure to mosquitoes from now until cold weather sets in, Mills told the BDN last week.
These precautions include wearing long pants, long-sleeved shirts and socks, and applying DEET or another effective insect repellent for extended outdoor activities such as outside work and school field trips.
While cases of EEE in humans are rare, Mills said, the severity of the virus should not be underestimated. Of those humans who become infected, more than 30 percent die, and half of those who survive suffer permanent neurological damage, she said.
Hoenig said a public meeting was held last week at Mount View High School in Thorndike for area residents since several of the ill horses were from northern Waldo County. Hoenig also spoke recently to members of the Maine Organic Farmers and Gardeners Association based in Unity, which will be host to the Common Ground Country Fair later this month.