A New York State resident from Ulster County died Monday after testing positive for the Eastern Equine Encephalomyelitis virus, prompting State Health Officer Dr. James McDonald to declare the case an imminent public health threat.

The incident occurred about a month after another mosquito-borne disease, West Nile virus, was first detected in the city this year.

Here’s everything you need to know about mosquito-borne viruses and their potential impact on the New York City area through October 31, when mosquito season ends, according to the Department of Health and Sanitation.

What is EEE? And what is West Nile virus?

According to the state Department of Health, the chances of contracting a mosquito-borne disease such as EEE or West Nile are low, but the diseases – for which there is no vaccine or cure – can be fatal.

The viruses are transmitted to humans through mosquito bites.

There are about five to 10 cases of people becoming infected by electrical and electronic equipment in the U.S. each year, according to the state Department of Health. Before Monday’s latest cases, there had been five cases involving a New York state resident since 1971, officials said.

How do I protect myself from these viruses?

The state health department recommends that people cover their skin and spray exposed areas with insect repellent when outdoors during the peak season for virus infection, from late July to September.

All openings in the house – windows and doors – should be screened with no cracks or scratches. And standing water should be removed from parts of the house where mosquitoes can breed. The Centers for Disease Control also recommends treating clothing and equipment.

What are the symptoms?

According to the state Department of Health, most people who become infected with WNV or EEE do not show any symptoms. According to the CDC, about one in five infected people show symptoms, and only one in 150 people become seriously ill and die.

But every case is different.

The first Manhattan resident to contract West Nile virus this year suffered slurred speech, low blood pressure and stroke-like symptoms, according to the woman’s son, Christopher Hartnick, a professor of otolaryngology at Harvard Medical School and Massachusetts Eye and Ear.

“Often with diagnosis comes treatment and a cure. Not with this virus. The more I read, the less confident I felt that we could make any predictions at all about Mom’s recovery,” he wrote in an opinion piece for Stat News on Tuesday.

The state health department said some people may experience symptoms such as fever, headache, body aches and even paralysis. Symptoms usually appear within three to 15 days of contracting the virus.