While no incidents of EEE have been registered so far in 2020, the Centers for Disease Control and Prevention (CDC) received reports of 38 confirmed cases (including 15 deaths) in 2019. That was a significant jump from 2018, when just six cases were reported. The Center for Food Security and Public Health at the Iowa State University of Science and Technology estimates that between 1964 and 2010 there were six cases a year on average, with one to two deaths annually. Richard Pollack, PhD, senior environmental public health officer at Harvard University in Cambridge, Massachusetts, warns that in the past, enhanced EEE activity has come in waves of two to three years, with the risk diminishing for about a decade or so in between. “If the virus is reading the playbooks from past years, this may be year two of a two- to three-year cycle,” he says. “But viruses don’t read, so it may not necessarily respond in the same manner as in the past.” People living in the Northeast and South, especially, may want to be on the alert. Infections showed up last year in Alabama, Connecticut, Georgia, Indiana, Massachusetts, Michigan, New Jersey, North Carolina, Rhode Island, and Tennessee. Historically, Florida and New York have also seen cases of EEE, according to the CDC. Unlike the flu and COVID-19, this virus is not transmitted through human contact but via mosquito bites. While the disease may not appear in humans until the fall, states are already testing their mosquito populations for signs of the virus. “It is too early [for people to get sick] in New England,” says Dr. Pollack, “but Massachusetts has begun monitoring.” RELATED: What Bit Me? Spot These 12 Bug Bites
Factors That Could Ease or Worsen the Season
Although experts have not pinpointed a single reason for the EEE surge last year, Stephen Rich, PhD, a professor of microbiology at the University of Massachusetts in Amherst, speculates that a larger mosquito population may have contributed. “We had a very wet spring [last year] here in Massachusetts,” he says, “and when there’s lots of water, there’s lots of mosquitoes.” This year, a drier spring could make a difference. “Most of the state [with Cape Cod as one of the exceptions] has been drier than in years past, so that’s probably going to keep the number of mosquitoes down,” says Dr. Rich, who is also an expert on zoonotic diseases (those that originate or are maintained in natural animal populations but occasionally affect human populations). On the other hand, the lifting of coronavirus lockdown restrictions could mean more people rushing outside and choosing hiking, camping, and beach vacations over city trips, increasing the number of individuals who may be exposed to infected mosquitos. Rich believes this has already led to a bump in tick-related Lyme disease. If that is any indicator, the same could hold true for mosquito-borne EEE. After spending months inside at home, people are eager to get outside. “They’re all going outside to play and they’re getting a lot more tick bites,” Rich says. “Plus, with everyone thinking about the consequences of COVID, they’re forgetting about other health risks — like EEE.” Pollack adds that possible contributing factors may include a new strain of virus that could be stronger and more readily transmitted, changes in climate that may have enhanced mosquito abundance and longevity, and changes in the landscape that may have enhanced habitats for mosquitoes, such as higher water tables in white cedar swamps or in cattail wetlands. RELATED: Could You Have Lyme Disease and Not Know It?
A Rare Disease With Serious Repercussions
“In comparison to the coronavirus, the total number of cases [of EEE] is trivial,” says William Schaffner, MD, an infectious disease specialist and professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville, Tennessee. “But for those who do get the virus, it’s pretty serious.” The virus typically produces symptoms of fever, headache, irritability, restlessness, drowsiness, loss of appetite, vomiting, and diarrhea. Signs of illness usually appear 4 to 10 days after a person is bitten by an infected mosquito. In milder cases, the body fights the virus off, and the illness resolves itself in one to two weeks, according to the CDC. But in severe cases, EEE can cause a lethal brain infection. The CDC estimates that about 30 percent of those who contract EEE die, and many of those who survive suffer from chronic neurological problems and brain damage, which may leave them with disabilities. “EEE likely has one of the highest mortality rates of viruses in North America,” says Pollack. “Those who do survive can be significantly burdened for the rest of their lives.” An article in The Washington Post illustrated how fast and devastating EEE may be. After contracting the virus, a Michigan man reportedly went from being perfectly healthy to brain dead in just nine days. Dr. Schaffner stresses that the infection can be “very nasty.” He explains, “Once you get bit, the virus has an attraction to the central nervous system, in particular the brain. When it finds its way there, it begins to destroy the cells of the brain.” The disease can produce a progressive stupor that leads to a coma. A patient may suffer from convulsions and general muscular spasms. There is no cure or treatment for the disease. “Symptoms can present abruptly and put people into intensive care where they can receive intravenous fluids, proper nutrition, and treatment for any convulsions, as their body fights off the infection,” says Schaffner. RELATED: Everything You Need to Know About Bug Bites and Disease
The History of EEE
Sometimes referred to as triple E or sleeping sickness, Eastern equine encephalitis is a type of arboviral disease, meaning the virus is spread to humans by the bite of an insect — in this case, a mosquito. The disease is commonly maintained in birds. Mosquitoes then can transmit it from birds to humans or horses, for example. The virus got its name because it was first recognized in horses in 1831 in the northeastern United States, according to the American Association of Blood Banks. Scientists identified it in humans in 1938, following a widespread outbreak in children that resulted in 30 cases of fatal encephalitis (an inflammation of the brain usually caused by a viral infection). “On the good news side, the virus is still relatively rare, and a very, very small proportion of mosquitoes are actually infected,” says Rich. “That’s not to say don’t worry about it, but do not let this rule your life.” RELATED: Why Mosquito Bites Itch and How to Get Relief
How To Protect Yourself
Although infected mosquitoes spreading EEE are not a health threat on par with the coronavirus, health officials recommend that individuals and communities take action now to head off trouble. Because mosquitoes often breed in standing, stagnant fresh water, Rich suggests that people empty out any planters, old tires, bird baths, old toys, or other receptacles that may be holding water. Dr. Schaffner advises residents to look up: “Check out your rain gutters. If they don’t have a good pitch and actually drain, they can pool water and mosquitoes can breed there.” RELATED: Bug Bite Danger Zones — Summer 2020 Alert In areas where infected mosquitoes have been detected, public health officials advise residents to wear long-sleeved shirts and pants, as well as use mosquito repellent with the active ingredient DEET. Rich recommends the insecticide permethrin because, he says, it kills mosquitoes whereas DEET simply repels them. People may also want to avoid going out at dawn and dusk when mosquitoes tend to be more active. Last year, several communities that detected infected mosquitoes launched large-scale pesticide spraying efforts. “These pesticides have pretty good safety profiles, and they’re usually sprayed in off hours when people are less likely to be outside,” says Rich. Pollack also urges residents to get involved with local efforts to help control the disease. “Contact your local board or department of health and your regional mosquito control abatement district to discuss what you can do to help them, and to learn what you and they might do to reduce your risks,” he says. Even though few people get infected each year, Pollack urges the public to take precautions against EEE seriously because of the deadly consequences. “I realize that it is human nature to think ‘It’s rare and it won’t happen to me,’” he says, “but that’s akin to playing Russian roulette.” RELATED: Study: Mosquitoes Find You (And Decide to Bite) Because They Can Smell Your Breath
