Wisconsin is the latest state to report a case of Eastern equine encephalomyelitis (EEE) — the deadliest mosquito-borne disease in North America with a mortality rate of around 30%, according to the U.S. Centers for Disease Control and Prevention (CDC). As of August 27, the CDC has recorded four human cases this year.

EEE can lead to neurological diseases such as meningitis and encephalitis and has no specific treatment. Many people who recover from it have long-term physical or mental problems, ranging from mild to severe intellectual disability and personality disorders to seizures, paralysis and cranial nerve dysfunction.

There are about a dozen human cases of electrical and electronic equipment exposure each year in the United States. Seven cases were reported to the CDC last year.

Earlier this month, health officials in Massachusetts reported a case of EEE in an 80-year-old man in the southeastern part of the state. According to NPR, this is the first case Massachusetts has recorded in four years. Still, health officials in other parts of the state have also detected EEE activity in mosquitoes, and some cities have imposed voluntary curfews starting at 6 p.m. and closed parks at sunset to reduce the risk of infection.

Two more human cases have been reported so far this year, according to the CDC — one in Vermont and one in New Jersey. The virus has also been actively detected in mosquitoes and other animals in Michigan, Florida, Georgia, Arkansas, Virginia, New York, Louisiana, New Hampshire and South Carolina.

Climate change has extended mosquito season and caused weather changes, making more areas in the U.S. suitable for mosquitoes, NPR reported.

As CMM previously reported, August is also the month with the most human infections of West Nile – the most common mosquito-borne disease. As of August 27, 289 cases of West Nile virus have been recorded in the United States, including the admission of Dr. Anthony Fauci, former director of the National Institute of Allergy and Infectious Diseases. So far this year, 33 Americans have died from West Nile.

In June, the CDC also issued an alert to warn the public about an increased risk of dengue virus infections in the United States. This year, there have been more cases of this mosquito-borne viral disease worldwide than ever before.