We haven’t seen rain for a bit, but it’s still in the 90s in Atlanta, and a pesky buzzing insect that thrives in heat and humidity, typically squished as it bites, remains a rare but potentially deadly health threat.
Eastern Equine Encephalitis, a virus resulting from a mosquito bite, caused the nation’s first human death of the year in New Hampshire, state public health officials announced this week. It was also the first human infection caused by the virus in the state in a decade.
New Hampshire’s public health officials cited an elevated risk of infections in New England when a person infected with the virus died after being in the hospital with severe central nervous system symptoms. The Centers for Disease Control and Prevention, which monitors the disease’s activity nationally, hadn’t updated its tally on Thursday to include the death. The agency recorded human cases in nearby Massachusetts and Vermont, along with New Jersey and Wisconsin.
The Eastern Equine Encephalitis virus rarely infects humans. The disease develops in less than 5% of those infected and only a few cases are reported in the United States each year ,mostly in eastern or Gulf Coast states, the CDC says. About 30% of people with the disease die within two weeks of the onset of flulike symptoms. Those who survive have ongoing neurological problems. There is no vaccine or treatment for infections in humans.
Last week, a Massachusetts town closed its municipal parks and fields to nighttime visitors amid a heightened risk of the virus. A man in his 80s had been exposed to the rare disease, which prompted state health officials to raise the risk level of the disease in nearby counties.
While the CDC isn’t aware of other deaths from the virus, the agency records cases in animals throughout the country, including in South Georgia. Irwin and Lowndes counties each reported to the CDC a single case of nonhuman encephalitis this year, as of August 27.
The cases of Eastern equine encephalitis in Georgia resulted in a veterinary disease or an infection in mosquitoes, birds, or sentinel animals, which can predict environmental hazards, such as dogs and cats, according to the CDC, which tracks the disease along with state health departments.
A veterinary disease case generally means a horse has the infection, said Daniel Mead, a professor in the College of Veterinary Medicine at the University of Georgia who helps monitor mosquito activity in the state. “When we see mammals [infected], that suggests an increased risk to humans,” he said.
The disease was first recognized in horses, thus the virus’ name, though there’s a vaccine for horses. Eastern equine encephalitis virus infections in horses do not increase risk for human infections because the concentration of virus in horses’ bloodstreams isn’t usually enough to pass the infection back to mosquitoes, the CDC says.
Mead was part of UGA’s Southeastern Cooperative Wildlife Disease Study team that detected infected mosquitoes in Lowndes County earlier this year.
He believes those who live in the southern and coastal parts of the state should be more concerned about the recent New England outbreak as those areas see the virus in mosquitoes every year. “Very rarely does it equate to human cases,” he said.
The same is true of the New England outbreak, said Mead, who is also director of UGA’s Animal Health Research Center. The virus is seen in mosquitoes every year there, but there haven’t been so many states with human cases in a short period, he said. “The number of cases and states involved is unusual for New England.”
The CDC said it typically sees three to 15 human cases of the virus a year, and an average of seven cases nationally as occurred last year. July through September is the peak season. For comparison, another mosquito-borne disease on the rise this year, the West Nile virus, has resulted in 18 deaths so far this year. Last year, there were 182 deaths from that virus, the CDC reports.
Georgia saw a spike in West Nile virus cases this week, according to the CDC. Cases tripled from two to six West Nile virus cases in a short amount of time. The majority of the cases were in metro Atlanta.
For now, the impact of equine encephalitis in Georgia is pretty low and isn’t a concern, Mead said. “I would be most afraid if I was one of the people who developed the disease. It is not a fun virus.”
Dr. Steven Fairchild, a Marietta veterinarian who treated horses earlier in his career, said he wasn’t “terribly alarmed” about the New England outbreak. For the first eight months of the year, few human cases were reported, despite a rise in mosquitoes, he said. “It’s probably nothing to worry about. All the people who go camping and hiking and do water events here and there’s not been a human case in Georgia.”
Fairchild was surprised, however, that the human cases were in the North instead of the South, where there would tend to be more swamps that breed mosquitoes. “A lot of times people travel down the Atlantic coastline where there’s an equine event.” If the states they visit have more mosquitoes, and if mosquitoes can infect birds and horses, they can also infect humans, he said.
Fairchild said most people bitten by a mosquito won’t show signs of illness. But if they’ve been in a place with a large concentration of mosquitoes and happen to notice signs of fever or neurological conditions such as disorientation should visit a doctor to determine if they have Eastern Equine Encephalitis.
Other symptoms include headache, vomiting, diarrhea, seizures, behavioral changes, and drowsiness. Though rare, a third of people with the disease die, typically in 2 to 10 days after onset of symptoms, the CDC reports. Those who survive have ongoing neurological problems such as intellectual impairment, personality disorders, seizures, and paralysis. Many patients with severe conditions require long-term care and die within a few years, the CDC says.
The best way to prevent the disease and reduce your risk of infection is to ward off mosquito bites.
The CDC and Georgia Department of Public Health recommend:
· Use insect repellent registered with the Environmental Protection Agency with DEET picaridin, IR3535, or oil of lemon eucalyptus.
· Wear loose-fitting, long-sleeved shirts and pants when outdoors
· Treat clothing and gear with permethrin
· Control mosquitoes indoors and outdoors
· After a rain or at least once a week, tip out standing water in flowerpots, planters, children’s toys, wading pools, and buckets. Throw away old tires, bottles, cans and other items that hold water.
· Ensure doors and windows fit tightly and are in good condition.
To learn more about disease and how to prevent it, visit the CDC or Georgia DPH.
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