Allegheny County Health Department confirms first human West Nile case of year

A Plum resident’s fever, malaise and digestive trouble since mid-July was confirmed to be the first human case of West Nile this year, according to the Allegheny County Health Department.

The person’s name and gender were not released, but the health department said the person is recovering at home.

West Nile fever is a viral disease spread by mosquitoes that was first identified about 80 years ago in east Africa. The first U.S. case was confirmed in 1999 in New York and, in the time since, the virus has become endemic among mosquitoes in parts of the country.

The virus was detected in mosquitoes in several areas of Allegheny and Westmoreland counties, particularly in eastern Allegheny County.

Dr. Amesh Adalja, an infectious disease expert based in the Pittsburgh area, told TribLive it was only a matter of time before a human case was reported this year.

“It’s not surprising, ” Adalja said.

The only way to prevent the spread of the virus is to kill and/or stop mosquitoes from breeding. That means eliminating any areas of standing water.

People can file a report about problem areas in Allegheny County here. The Centers for Disease Control and Prevention offers resources here.

It’s tough to completely eliminate mosquitoes because they can breed in the amount of water contained in a discarded bottle cap, Adalja said.

The health department has also been spraying Zenivex E20, what it calls a low-risk pesticide, in problem areas.

Most of the people who are exposed to the virus don’t even report symptoms, Adalja said.

Others, like the person in this most recent case, present symptoms that are flu-like and recover.

In rare cases, the virus spreads to the brain, where it causes inflammation and can be fatal.

The last Allegheny County death from the virus was reported in 2023 when an octogenarian from Pittsburgh’s Elliott neighborhood contracted the disease and died.

West Nile tests can be performed by health care providers, and the health department logs positive tests along with other vectorborne (spread through insect bites) diseases. Since 2017, there have been 17 cases, 14 hospitalizations and one death, according to departmental records.

Westmoreland County doesn’t have a health department, but the Westmoreland County Conservation District administers a West Nile program.

As of July 31, 15 sites have reported mosquitoes infected with West Nile. They were in Youngwood, West Newton, Rostraver, New Kensington, Derry, Jeannette, Latrobe and Greensburg. In addition, one site in New Florence tested positive for Jamestown Canyon virus.