A York County man has been confirmed as Maine’s first-ever human case of Eastern Equine Encephalitis, a rare but potentially deadly disease carried by mosquitoes, according to the Maine Center for Disease Control and Prevention.
The man, whose name was withheld in accordance with privacy guidelines, first experienced mild symptoms in late July, Maine CDC Director Dr. Sheila Pinette said. In mid-August, he developed a fever, severe headache and confusion, and was hospitalized in York County for a week, then transferred to Boston, she said.
“The individual is home recuperating at this time, after a long hospitalization and rehab, and is doing fairly well with some mild [neurological] deficits,” Pinette said.
The man is over age 60, she said.
Most individuals infected with the EEE virus experience no symptoms of illness, according to the U.S. CDC. But in 4 percent to 6 percent of diagnosed EEE cases, patients develop a severe form of the virus that causes neurological symptoms, such as brain swelling.
One out every three EEE patients with inflammation of the brain dies. Many survivors suffer memory, speech or cognition problems. Small children and older adults have a higher risk of developing neurological problems related to viral infections, Pinette said.
Blood samples collected from the York County man on Oct. 1 tested positive for the virus at a commercial lab, according to a Maine CDC health alert issued Friday. The state’s testing lab subsequently confirmed the results on Oct. 9 and the sample was forwarded to the U.S. CDC for further confirmation.
Medical staff checked the patient for EEE in late August, but tests didn’t detect the virus until October, Pinette said. Samples collected early in the course of the illness may come back negative.
While the EEE virus has been found in mosquitoes, birds and animals in Maine, the case marks the first confirmed time a human has contracted the disease in the state. Maine was among the last New England states to avoid a human case.
The illness reappeared in Maine after killing 15 horses in 2009. In 2012, a flock of 30 farm-raised pheasants in Lebanon died from EEE. Last year, the virus led to the deaths of two horses in Maine.
In August, Maine CDC announced a New Hampshire resident was hospitalized at Maine Medical Center in Portland with EEE. The patient contracted the viral illness in New Hampshire but needed the high level of care available at MMC, according to health officials. That individual later died, Pinette said.
A visitor to the state from Massachusetts died from the disease in 2008.
Among those infected with EEE, the illness begins with a sudden headache, high fever, chills and vomiting lasting one to two weeks. The illness may then worsen, causing disorientation, seizures or coma.
EEE has no cure. Treatment consists of supportive care, including mechanical ventilation, IV fluids, and medication to control seizures and reduce brain swelling.
This year, Maine CDC has detected the EEE virus in 22 mosquito testing pools in York County and an emu in Cumberland County that died from the illness. Seven mosquito pools collected on Sept. 30 tested positive for EEE, prompting the agency to extend the mosquito trapping season until Oct. 15, according to the alert.
Mosquitoes may remain active when temperatures are above 50 degrees.
A bond question due to go before voters in November would improve Maine’s surveillance for EEE, according to officials with the University of Maine’s Cooperative Extension.
The extension formerly assisted Maine CDC in monitoring mosquitoes for both EEE and West Nile virus, explained Jim Dill, a pest management specialist. But the extension was forced to stop in 2008 due to a lack of funding and U.S. CDC protocols governing safe handling of mosquitoes collected for testing, he said.
If Question 2, an $8 million bond initiative, passes in November, the cooperative extension plans to build a new facility in Orono to house labs for the monitoring and testing of insects and pests that afflict domestic and wild plants and animals in Maine. The planned facility includes a biosecure lab that would allow the extension to revive its mosquito traps in the northern part of the state and prepare the bugs for testing in Augusta, Dill said.
The state has tested about 400 mosquito traps this year from York, Cumberland, Oxford, Kennebec, Waldo and Aroostook counties, said Chuck Lubelczyk, a vector ecologist at the Maine Medical Center Research Institute, which partners with Maine CDC on testing. But some parts of the state — including Down East, the area between Rangeley and Jackman, and unmonitored parts of Aroostook — lack mosquito traps, he said.
“If you were to look at Maine in terms of a net, for surveillance, we would have more holes in the net than we actually have netting,” he said.
Surveillance of wildlife shows EEE occurs throughout the state, Lubelczyk said.
“The real question we don’t know is, why is it showing up so prevalently in wildlife and we have so few cases in those areas in humans?” he said.
Maine CDC issued Friday’s health alert in hopes of encouraging Mainers to consider EEE when spending time outdoors, including sportsmen heading into the woods to hunt, Pinette said.
“Prevention’s the key here … Our goal is not to alarm people, it’s just to make sure that they’re aware,” Pinette said.
Maine CDC recommends the following preventive measures to protect against mosquito-borne illnesses, such as EEE and West Nile virus:
— Avoid spending time outdoors at dawn and dusk when many species of mosquitoes are most active.
— Use an EPA-approved repellent when outdoors and always follow the instructions on the product’s label. Lemon eucalyptus oil is a natural alternative.
— For children under three, use netting on strollers.
— Wear protective clothing when outdoors, including hats, long-sleeved shirts, pants and socks.
— Use screens on windows and doors to keep mosquitoes out of the home, and patch any holes.
— Empty standing water where mosquitoes can breed, such as from flower pots, tire swings, buckets and barrels.
