Update: Additional mosquito samples reveal presence of rare virus

UPDATE (Aug. 31): The New York State Department of Health has informed Suffolk County health officials that two additional mosquito samples taken from Manorville have tested positive for the virus known as “Triple E.” The samples were collected Aug. 22. The first sample that tested positive and was taken Aug. 16.

Suffolk County treated areas of Manorville and Calverton Wednesday night in response, officials said.

Original story (Aug. 26): A mosquito sample collected in the Manorville area tested positive for eastern equine encephalitis virus, also known as “Triple E,” according to the New York State Health Department. The finding has prompted a declaration of an “imminent threat to public health for Suffolk County.”

The designation allows Suffolk County to take steps to control mosquito populations.

The sample that tested positive was collected Aug. 16, the health department said. It was the first positive sample in Suffolk County since 2008.

Triple E is a rare but deadly illness for humans. The disease is also a concern for horses, though a vaccine is available and recommended for horses. Similar to West Nile virus, Triple E is transmitted by the bite of an infected mosquito.

“The reason EEE is less common in humans is that the primary mosquito vector, Culiseta melanura, does not typically feed on humans,” Dr. James Tomarken, the Suffolk County Commissioner of Health Services, said in a press release. “However, the virus may be transmitted to humans and horses by bridge vectors, which are other kinds of mosquitoes that have contracted the virus by feeding on infected birds.”

There are approximately 5 to 10 humans cases of Triple E reported annually in the U.S., according to the state health department. There have been 12 cases reported in New York State since 1952. To date, there have been no human cases in Suffolk County.

In a severe case of Triple E, a person may experience swelling of the brain that can be deadly. The mortality rate of those that develop the virus is about 33 percent, the highest among human viruses that are transmitted by arthropod vectors such as mosquitoes or ticks in cases reported in the U.S. There is currently no human vaccine for Triple E and patients are treated with supportive care.

The health department noted additional mosquitoes have tested positive for West Nile this month across Suffolk County, including two samples in Southold and one in Aquebogue.

To date, Suffolk County has reported 92 samples that have tested positive for West Nile. No humans or horses have yet to test positive.

The county health department urges residents to take steps to help control mosquito populations by eliminating any standing water on their property. Dr. Tomarken is also urging residents to take steps to be even more vigilant, especially those who live or visit the Manorville area.

People, especially those age 50 or higher, or with compromised immune systems, are urged to take precautions to avoid being bitten by mosquitoes. Some steps include:

· Minimize outdoor activities between dusk and dawn.

· Wear shoes and socks, long pants and long-sleeved shirts when mosquitoes are active.

· Use mosquito repellent.

· Make sure all windows have screens that are in good repair.

· Once a week, empty and scrub, turn over, cover or throw away containers that hold water such as vases, pet water bowls, flowerpot saucers, discarded tires, buckets, pool covers, birdbaths, trash cans and rain barrels.

Read more about mosquito protections here.