The first human case of West Nile virus in Delaware County for 2025 has been identified, the county's health department announced on Tuesday.

The Delaware County Health Department did not reveal the person's gender, age or where they live in the county. 

Human cases of West Nile virus in Delco aren't uncommon and occur in most years, according to the health department. The number of human cases of West Nile virus previously peaked in 2012, 2018 and 2021, the health department said. Within the last five years, the highest number of human cases was 4, in 2021. 

Fortunately, the majority of those who do get infected with West Nile virus don't develop any symptoms, the health department said. About 1 in 5 people infected develop a fever, headache, body aches, joint pains, vomiting, diarrhea or a rash. Most people who develop symptoms make a full recovery; however, fatigue and weakness related to the infection could last for weeks or even months.

West Nile virus detection in mosquito pools, as well as mosquito bites, remains prevalent at the end of the summer season. 

Delco residents should stay aware and continue to take precautions when outside, as mosquito activity typically lasts into the fall season. 

There are three easy ways to protect yourself from being infected with West Nile virus: drain standing water on your property at least 1-2 times a week, dress in long-sleeved shirts and pants and defend yourself with bug spray that has DEET, Picaridin, or Oil of Lemon Eucalyptus when outdoors.

Since the start of the year, 108 mosquitoes have tested positive for West Nile virus in Delaware County, according to the Pennsylvania Department of Environmental Protection. 

Multiple human cases of West Nile virus were reported by the New Jersey government on Aug. 29, including one in a child in Atlantic County.