Protection against bites just got more important than ever
Dr. Jan Patterson, Published in Wise & Well, Sept 25, 2024
Steven Perry, a 41-year-old New Hampshire man, was physically active and healthy when he contracted a rare disease from a mosquito bite. Perry developed rapidly progressive symptoms and died within a week
His grieving family wants people to know about the disease—Eastern equine encephalitis—and how to prevent it.
Until recently, Eastern equine encephalitis (EEE) had been rare in the US, but lately it’s been making headlines. Despite cooler temperatures that are less favorable to the insects, reported cases continue, and as of Sept. 21, there have been 11 cases of EEE in seven states, primarily in the Northeast.
The deadliest animals
Tiny as they are, mosquitoes are the deadliest animals on earth. They transmit malaria, West Nile virus, dengue, yellow fever, and other serious diseases. Malaria accounts for most of the deaths due to mosquitoes. In 2022, there were more than 600,000 deaths globally, affecting 85 countries.
Prevalence of EEE in non-humans has, in recent years, been detected in mosquitoes and animals over a larger area of the US. The virus includes the name “equine” because it was first detected in horses.
Unlike malaria, which is transmitted by mosquitoes after biting an infected person, EEE-carrying mosquitoes usually acquire the virus from biting infected birds. EEE is found primarily in eastern or Gulf Coast states. There is also a Western equine encephalitis that has occurred primarily in the Western US, but it is quite rare here and there have been no reported cases in the US since 1999.
Tricky to diagnose
People bitten by an EEE-infected mosquito may not experience any symptoms. Or they may experience non-specific symptoms of a viral illness — fever, chills, vomiting, and headache.
Severe cases lead to encephalitis, a swelling of the brain that causes seizures and coma.
The disease is diagnosed based on symptoms in a person who has been in an area where EEE is present. Laboratory diagnosis requires a blood or tissue sample for antibody or molecular testing.
About one-half of the encephalitis cases cause long-term neurological complications, and about one-third of the encephalitis cases are fatal.
Over the last two decades, about 10 cases of EEE occur each year in the US. However, experts believe that the longer mosquito-breeding season and changing bird migration patterns due to climate change may lead to an increased number of cases in temperate climates.
There is no vaccine or antiviral for EEE, so prevention is key.
Some health departments may spray pesticides in affected areas. Personal protective measures include emptying any standing water around living areas — mosquitoes need only a bottle-cap of water in which to lay eggs, wearing long sleeves and long pants when outside, and using an effective EPA-approved insect repellent including DEET or picaridin.
DEET has been considered the gold standard in insect repellents and is safe when used as directed, but the odor and oiliness is objectionable to some. It can damage plastics and synthetic fabrics. Picaridin has been shown to be as effective as DEET when used as directed, has less odor and oiliness, and is not a plasticizer. Outdoor fans can also help keep mosquitoes away.
A bigger concern
Protecting against mosquito bites protects you against other possible viral infections.
The most common mosquito-borne illness in the US is West Nile virus (WNV). It has been reported across 48 states since its introduction to the country 25 years ago. It has caused 59,000 detected cases and 2,900 deaths. Since most cases do not cause illness, the disease is underreported. Those who become ill can have headache, fever, weakness, aches, and pain.
This year, 659 cases of WNV have been reported and about 70% of these have been serious, invading the brain or nervous system. One of the nation’s leading infectious diseases physicians, Dr. Anthony Fauci, was hospitalized with WNV this year.
“I’ve never been as sick in my life,” Fauci said. “Ever. By far, this is the worst I have ever been with an illness.”
Serious cases of WNV can result in encephalitis or paralysis in some parts of the body. There is no vaccine or antiviral for WNV.
Mosquito-borne diseases are a threat each year until a hard freeze eliminates most of them. Until then, preventive measures are the best defense against infections and potentially serious complications from these diseases.
More from Dr. Jan on Medium.com & Wise & Well
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