Rare mosquito-borne viral infection that has killed 14 Americans may be linked to climate change
The dangerous mosquito-borne Eastern Equine Encephalitis (EEE), has recently killed a Michigan farmer, making it the sixth such death in the state. Overall, the virus has affected 36 people and killed 14 others in the US, according to the latest estimates from the Centers for Disease Centers and Protection (CDC). The rise in the number of cases, according to experts, could be tied to climate change.
The virus is considered rare in the country, with nearly seven human cases of EEE reported annually. However, this year, things are looking different. EEE virus has been found in 421 mosquito samples this year, reports the Massachusetts Department of Public Health.
EEE is a rare virus that spreads through mosquitoes. The virus can infect the brain, causing brain swelling or lead to flu-like symptoms, including a high fever, chills and nausea. Severe cases can result in seizures or a coma that can cause brain damage, says the CDC. The virus kills nearly one-third of its victims, leaving those who survive with brain dysfunction, personality disorders, seizures, paralysis, and other complications.
"We continue to emphasize the need for people to protect themselves from mosquito bites. It is absolutely essential that people take steps to avoid being bitten by a mosquito," Massachusetts Public Health Commissioner Monica Bharel said in a news release last month.
Besides affecting 10 people in Michigan, cases of EEE have been reported in seven other states, with the largest number of confirmed cases coming from Massachusetts. The other affected states include Connecticut, Indiana, North Carolina, New Jersey, Rhode Island and Tennessee.
"Before this year, we have had only one human case of EEE in Connecticut, and that was in 2013," Dr. Matthew Cartter with the Connecticut Health Department told CNN. This year Connecticut has seen four confirmed cases.
Is climate change to be blamed?
This rise in the number of EEE cases can be attributed to climate change, which, in turn, facilitates the spread of the virus, according to Lt. Gov. Susan Bysiewicz, Connecticut’s Lieutenant Governor.
Experts agree. These mosquitoes which drive the spread of virus thrive in warmer temperatures and this year proved to be just that: September 2019 was the hottest on record for the planet, according to the National Oceanic and Atmospheric Administration (NOAA). The organization adds that the 10 warmest years on record have all occurred since 1998, and 9 of the 10 have occurred since 2005. This had extended breeding season of mosquitoes, leading to an increase in the mosquito population and the rates of infection.
“The longer the breeding season, the more baby mosquitoes that are going to hatch and the more your chance of getting bitten,” George Rutherford, a professor infectious disease and epidemiology at the University of California, San Francisco, told USA news.
Warmer temperatures may have extended the circulation of cattail mosquitoes, which act as a bridge, helping the virus transmit itself between birds and humans. "Normally, there is one generation of the species in his region [Michigan] that peaks in mid-July and trails off in numbers by late August. This year, we are still catching them now. This suggests to me that they are either living a very long time or there is a partial second generation,” Edward Walker, a professor of entomology at Michigan State University told Scientific American, last month.
However, Skinner thinks we will see fewer cases of EEE once states see a hard freeze. Still, he urges people to protect themselves from bites and eliminate mosquito breeding sites from their homes. He adds, “EEE is one of the more serious mosquito-borne diseases that we see as far as the consequences it can have on people’s health. But it’s one that can be prevented if people adhere to the precautions we recommend.”