New Jersey Reports Initial Human Cases of West Nile Virus for 2025, Including a Child

State health officials have confirmed the first human cases of West Nile Virus (WNV) for 2025, which include a child from Atlantic County, signaling the start of the annual transmission season for the mosquito-borne illness.

According to a news release from the New Jersey Department of Health (NJDOH), the first confirmed case involved a child who developed symptoms in the third week of July. A second case, an adult in Middlesex County, reported symptoms in the first week of August. Both individuals were hospitalized but have since been discharged and are recovering at home.

The department is also investigating four additional suspected human cases. A separate, asymptomatic infection was identified in a Sussex County resident through a blood donation screening.

“While the number of WNV human infections is lower than last year, we are seeing high levels of virus circulating in mosquitoes,” said Acting New Jersey Health Commissioner Jeff Brown. “As mosquito season can last into early November, depending on weather conditions, bite prevention will be essential.”

The announcement serves as a annual public health reminder of the virus’s presence. While many infected individuals show no symptoms, approximately one in five will develop West Nile fever, which can include fever, headache, body aches, and vomiting. In rare cases—less than 1%—the virus can cause severe neuroinvasive disease, leading to encephalitis or meningitis, which can be fatal. Individuals over 50 and those with compromised immune systems are at highest risk.

Regional Activity and Public Health Recommendations

The virus has been detected throughout the Northeast U.S. this summer. Neighboring Pennsylvania has reported 19 human cases across nearly all of its counties. New York City health officials recently announced two confirmed cases in Queens residents, and Erie County has reported one human case.

To prevent infection, health officials urge residents to:

Use EPA-registered insect repellent.

Wear long-sleeved shirts and long pants.

Eliminate sources of standing water around properties where mosquitoes breed.

Ensure window and door screens are intact.

Use mosquito netting over infant carriers and strollers.

“Standing water that pools in yard items such as empty planters serves as mosquito breeding grounds that cause the number of mosquitoes to grow rapidly and increase your risk of serious mosquito-borne diseases,” said Environmental Protection Commissioner Shawn M. LaTourette.

The state’s surveillance has found the virus in mosquito populations in all 21 counties, with the highest activity currently reported in Bergen, Middlesex, Union, Essex, and Hudson counties. Last year, New Jersey recorded 41 human cases of West Nile virus, including eight fatalities.