BRANDON — Sixteen emus on a farm in Brandon have died in what is Vermont’s first documented case of Eastern Equine Encephalitis.
Area veterinarian Keely Henderson sent brain tissue and blood samples from the dead emus to a University of New Hampshire lab last Wednesday, Sept. 21, and the results were received late next day.
Henderson said people with livestock need to make sure their EEE inoculations are up to date, and state Health Department officials urged people to take standard precautions to avoid mosquito bites.
“My recommendation for clients is that if they do live in an area with a heavy mosquito population they should re-vaccinate their horses,” Henderson said.
While this is the first documented case in Vermont, it seems as though it was only a matter of time. The Vermont Department of Health collected blood samples from deer and moose during the 2010 hunting season and evidence of EEE infection was found, but the animals were not sick. And although this was first time evidence of EEE virus has been detected in Vermont livestock, Henderson said she believes it has been in the state for a while.
“It’s not to say that EEE has never been here, it’s just never been diagnosed,” Henderson said on Friday. “The people that don’t vaccinate their horses don’t order a necropsy when they die, so it’s entirely possible that EEE has killed horses in Vermont and we just don’t have proof.”
Erica Berl is an infectious disease epidemiologist with the Vermont Department of Health. She said she is not surprised at the confirmed EEE diagnosis, given that the disease has been detected in New Hampshire, central Maine and Quebec.
“It’s been all around us, so there’s no really great reason why Vermont wouldn’t get it eventually,” she said.
The EEE virus typically infects birds, then mosquitoes become infected by feeding on infected birds. If an infected mosquito bites a horse, human or other mammal, the animal or person can become sick.
The virus that causes EEE is only spread by mosquitoes; it can not be spread by humans consuming emu meat or using emu products. People, horses and deer do not spread the disease. Although EEE most commonly affects people and horses, it is not uncommon to see it reported in emus, as well as alpacas, llamas, donkeys, and pheasants.
The health department says that symptoms of EEE typically occur four to 10 days after a bite from an infected mosquito. The severity of the illness varies and many people bitten by an infected mosquito will not become ill. Most people who become ill experience a flu-like illness with fever, headache, muscle aches, joint pain and fatigue. This illness can last one to two weeks.
In very rare cases, infection of the brain and spinal cord occurs, causing a sudden high fever, stiff neck and a headache that keeps getting worse. Inflammation and swelling of the brain, called encephalitis, is the most dangerous complication. There is no specific treatment for EEE. Doctors treat the illness by providing supportive therapy to lower the fever and ease the pressure on the brain and spinal cord.
Also, there is no vaccine because EEE occurs so rarely in people. There is a vaccine for horses, a combination shot of vaccines for EEE, Western Equine Encephalitis and West Nile Virus, which can also be used in other susceptible animals.
THE BRANDON EMUS
Brandon emu breeder Ann Breen said the 16 birds she lost died quickly, and she hopes it was painless.
“You can’t tell if an emu has a headache, so you don’t know how they’re feeling,” she said.
Breen said the birds got sick last Wednesday and all 16 were dead by Friday. Emus present EEE symptoms of bloody diarrhea and unsteadiness.
“They just die very quickly,” Breen said. “You see bloody patches on the ground and then they’re dead.”
Unlike horses, which contract the disease directly from a mosquito bite, emus — a flightless bird from Australia — can transfer it between individuals via feces, making entire flocks much more susceptible.
The threat posed by EEE to the emu population in the U.S. is not new. According to the Emu Association of America, there were numerous confirmed reports of emus with EEE in New England and along the East Coast during the late summer and early fall of 2009
“Each year we hear about outbreaks that occur throughout the United States,” the group states on its website. “Local veterinarians are usually notified by the state agricultural veterinary department if there is an outbreak in their area. This is a reminder to contact your local veterinarian and ask to be informed if EEE is found in your area. If EEE is found locally, the recommendation is to vaccinate your entire flock.”
That is what the Breen and her husband, Peter, are preparing to do. With more than 100 emus in their flock, there is a lot at stake. Each bird is worth roughly $800, and they are bred for their meat as well as emu oil, which is used to make everything from beauty products to healing salves to dietary supplements.
Trouble is, vaccinating an emu is no easy task.
“They panic so easily,” Ann Breen said. “It’s just about impossible to hold onto one when it starts to run, and they can run up to 35 miles an hour. They have super strong legs with sharp claws on the ends, so it’s pretty easy to get sliced open.”
Breen lost her best breeding trio of birds to EEE, but said the trio that lives in the neighboring pen has not gotten sick. Either way, she already expects next year’s breeding season to be severely affected by the EEE outbreak in her flock.
“Any messing with the breeding pairs and the trios in the fall can mess up next year’s breeding season,” she said. “It already has.”
WAITING FOR WINTER
Winter frosts that eliminate the mosquito populations will help to bring the EEE threat to an end for this year. With an extraordinarily wet spring followed by above-average late summer rainfall courtesy of Tropical Storm Irene, the Brandon-Leicester-Salisbury-Goshen Insect Control District has had its hand full keeping the mosquito populations down. It was a remarkably less buggy summer than expected until Irene hit on Aug. 28, dumping a record seven to nine inches of rain over 24-hours.
Breen said the district has been very responsive, having sprayed her farm specifically twice in  four days last week.
The latest hatching produced a particularly aggressive breed of mosquitoes in the district, but Erica Berl said that there is no correlation between a hatching of more aggressively biting mosquitoes and an increase in the number of EEE cases. She also said that only certain breeds of mosquitoes carry the EEE virus.
“Most of the nuisance biters are not big transmitters of the disease,” she said.
“The best defense for people living in mosquito-prone areas is to avoid being bitten.”