First Cases of West Nile Virus Reported in New Jersey

State Health Departments Urge Residents to Take Precautions Against Mosquito-Borne Diseases

The New Jersey Department of Health (NJDOH) has confirmed the first human cases of West Nile virus (WNV) in the state for 2024. Two individuals, a senior from Union County and a minor from Middlesex County, tested positive for the neuroinvasive disease with symptom onset in early July. Both patients were hospitalized and have since been discharged. Additionally, an asymptomatic WNV-positive blood donor was reported in Somerset County.

These cases mark an earlier-than-usual start to the WNV season, which typically sees most infections between mid-August and mid-September. Last year, New Jersey reported 14 human cases of WNV.

“This year, New Jersey is seeing higher than average West Nile virus activity earlier than expected. As mosquito season can last into October, bite prevention will be essential in protecting yourself and your family against mosquito-borne diseases like West Nile virus in the remaining summer months and into the fall,” said New Jersey Health Commissioner Kaitlan Baston, M.D. “This means avoiding mosquito bites through tried-and-true methods, like using insect repellants, wearing long sleeves and pants, and limiting outdoor activity during peak times for mosquito activity.”

Precautions and Risks

Residents are advised to take precautions against mosquito bites, including using EPA-registered insect repellants, avoiding outdoor activities during peak mosquito activity at dawn and dusk, wearing long sleeves and pants, and ensuring window and door screens are intact.

While many WNV infections are mild or asymptomatic, about one in 150 cases can develop severe symptoms, such as high fever, neck stiffness, and neurological issues. Older adults and individuals with weakened immune systems are at higher risk for severe illness.

“After a very wet early summer, it is more important than ever that everyone do their part to safeguard public health by removing standing water from their properties and covering empty outdoor containers that can quickly become mosquito breeding grounds,” said New Jersey Environmental Protection Commissioner Shawn M. LaTourette. “Even small amounts of rain can produce significant numbers of container-inhabiting mosquitoes known to spread West Nile virus. The NJDEP continues working closely with every county’s mosquito control program and posting safety guidance for residents to ensure they protect themselves and their families from the bites of mosquitoes.”

Surveillance and Control Efforts

This year, the detection of WNV in mosquitoes has occurred earlier and at higher rates, with 286 positive mosquito pools identified across all New Jersey counties except Cumberland. The northeastern part of the state, particularly Middlesex, Hudson, Bergen, and Union counties, has seen the highest activity.

In addition to WNV, Eastern Equine Encephalitis (EEE), another serious mosquito-borne disease, has been detected in Cape May, Morris, and Union counties. State and county mosquito control programs are working diligently to reduce transmission risks.

“Animals that are vaccinated are much less likely to contract serious mosquito-borne illnesses such as West Nile Virus and Eastern Equine Encephalitis,” said New Jersey Department of Agriculture (NJDA) Secretary Ed Wengryn. “Along with best practices like reducing standing water on farms, we strongly encourage horse owners to take this important step to protect their animals.”

Residents are encouraged to reduce mosquito breeding sites by eliminating standing water on their properties and keeping horse vaccinations up to date. The NJDOH provides testing assistance for WNV and other arboviruses, with detailed information available on their website.

New Jersey's surveillance and prevention efforts involve collaboration between federal, state, and local agencies, including the NJDOH, NJDEP, NJDA, CDC, and local health and mosquito control agencies. For more information and updates, visit the NJDOH website.

Resources:

NJDOH - West Nile Virus Webpage: nj.gov/health/cd/topics/westnile.shtml

NJDOH - Interactive Vector-Borne Disease Dashboard: dashboards.doh.nj.gov/views/public_dashboard/Intro

NJDOH - Weekly Vector-Borne Surveillance Reports: nj.gov/health/cd/statistics/arboviral-stats

NJDEP - Mosquito Control Webpage: nj.gov/dep/mosquito

NJDA - Animal Health Webpage: nj.gov/agriculture/divisions/ah