Expert: An 'average year' for West Nile virus conditions doesn't mean it's gone

In 1999, a mysterious virus grabbed headlines as scientists and government officials scrambled to understand and contain it. People who were bit by infected mosquitoes experienced fever, muscle weakness and neurological problems. Those over the age of 50 were at the greatest risk.

The panic over the West Nile virus subsided, even though it returns every summer and typically lasts until the middle or end of October. Experts say Long Islanders should remain vigilant while the temperatures cool and the season winds down.

Officials said there are four human cases in Nassau County this year and none reported in Suffolk. New York City has recorded six human cases and one death in 2020. Infected mosquitoes have been found in several parts of Suffolk, including West Babylon, Lindenhurst, Farmingville, Brentwood and Northport.

Newsday spoke with Dr. Scott Campbell, an entomologist and chief of Suffolk County’s Arthropod-Borne Disease Lab in Yaphank, about the West Nile virus.

Q: How does this season compare with previous years?

A wet spring followed by a hot dry summer is where we've seen the highest activity. Our highest years have been 2010 and 2012. This season is an average year because while we had rain in the spring and plenty of mosquitoes, our summer really didn't get hot and dry. So it kind of fluctuated. We’d see activity, and then it would decrease a little bit. It never really increased and continued to increase in activity through the weeks of the mid to late summer. And that's usually the driving force with regards to human cases.

Q: Should people be careful even if they don’t see infected pools in their neighborhoods?

A: We can't collect mosquitoes in every neighborhood. And the range of the mosquito that drives West Nile is about a mile … We look historically at activity and locations where we've seen it in the past, and we are mindful of anything that may be emerging. We use dead bird surveillance to try to identify areas where we are not necessarily trapping mosquitoes. If we start to see dead birds that are positive for West Nile in a certain location, we’ll respond by collecting mosquitoes in that area to see if something is going on there … So it's important for residents to be mindful that West Nile isn't gone because of COVID.

Q: Is West Nile virus season over?

A: Nights in the high 40s and low 50s really starts to knock down the mosquito population. So you're going to see fewer and fewer mosquitoes … but they're still active and we collect mosquitoes into the first full week of October. So people really need to be cognizant of not being bitten by mosquitoes.

Q: Are you concerned because more people might be spending time outdoors due to COVID-19?

A: There are people studying the response of people to COVID-19 and their outdoor activity. And when anybody is outdoors, they need to be cognizant of the risk of both tick-borne and mosquito-borne pathogens and diseases … The big message is [West Nile] is endemic and people just can’t forget about it or become complacent about it being here.

By Lisa L. Colangelo

lisa.colangelo@newsday.com@lisalcolangelo

Lisa joined Newsday as a staff writer in 2019. She previously worked at amNewYork, the New York Daily News and the Asbury Park Press covering politics, government and general assignment.