NJDOH, NJDEP, and NJDA Urge Precautions to Protect Against West Nile Virus

TRENTON – The New Jersey Department of Health is reporting the state’s first human cases of West Nile virus (WNV) this year.  

A child tested positive for West Nile virus neuroinvasive disease in Atlantic County with symptoms reported the third week of July. An adult in Middlesex County also tested positive for West Nile virus neuroinvasive disease with symptoms reported in the first week of August. Both residents have been discharged from the hospital and are recovering at home. Four suspect cases of WNV are currently under investigation. An additional report of an asymptomatic WNV-positive blood donor was reported in a Sussex County resident.  

Most WNV cases occur between mid-August and mid-September. In a typical year, there are 14 human WNV infections reported, although that number can vary substantially year-to-year. Last year, New Jersey had 41 human cases of WNV, including eight fatalities.  

“While the number of WNV human infections is lower than last year, we are seeing high levels of virus circulating in mosquitoes. As mosquito season can last into early November, depending on weather conditions, bite prevention will be essential in protecting yourself and your family against mosquito-borne diseases like West Nile virus in the remaining summer weeks and into the fall,” said Acting New Jersey Health Commissioner Jeff Brown. “This means avoiding mosquito bites through tried-and-true methods, like using insect repellents, wearing long sleeves and pants, and taking steps to keep mosquitoes outside the home.”  

For many people, WNV causes asymptomatic infection. One in five persons will develop a mild to moderate illness, typically with a fever, chills, headache, body aches, joint pains, vomiting, diarrhea, or rash.  

Less than 1% of people infected will develop a more severe form of the disease that affects the central nervous system, requires hospitalization, or results in death. People over age 50, with certain chronic medical conditions, and with weakened immune systems are at greater risk of developing severe illness. Symptoms include a severe headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. Recovery from severe illness can take several weeks or months. Some effects might be permanent. 

Early symptoms of WNV may be confused with COVID-19 or several other common viral illnesses. Specific laboratory tests are needed to confirm WNV, but there is no specific treatment. The best way to prevent the disease is to avoid mosquito bites. Persons who think they might have WNV or another mosquito-borne disease should contact a health care provider.  

To protect against mosquito-borne diseases, residents should: 

• Wear EPA-registered insect repellent. 
• Treat clothing with permethrin or use pre-treated clothing. 
• Wear long sleeves and long pants and cover exposed skin. 
• Cover cribs, strollers, and baby carriers with mosquito netting. 
• Mosquito-proof your yard and home by dumping standing water.  
• Use air conditioning, when possible, and use well-maintained window and door screens to keep mosquitos outside of your home. 

“We are urging the public to not let their guard down and continue to protect themselves from mosquito bites by turning over or removing items that collect water in order to eliminate all standing water on their property. 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. “While the DEP continues to support the needs of local mosquito control programs, it’s important that each of us do our part to protect public health.” 

WNV and Eastern Equine encephalitis (EEE) are arboviral diseases that people most often acquire through the bite of a mosquito that has fed on an infected bird or other animal.  

This year, the first detection of WNV in mosquitoes was in April, which is considerably earlier than expected. WNV has been detected in 776 mosquito pools, which is higher than this time last year, which was a very busy WNV season. WNV has been detected in all New Jersey counties. WNV detections in mosquitoes are highest in the northeastern part of the state, particularly in Bergen, Middlesex, Union, Essex, and Hudson counties.  

Apart from WNV, which is the most commonly reported locally-acquired, mosquito-borne disease, EEE, a rare, but severe infection, has been detected in mosquitoes in Atlantic County. The state and county mosquito control programs are working together to minimize potential transmission of these diseases to humans.  

In addition to causing human illness, WNV and EEE can harm certain birds and animals, including horses. WNV and EEE affect a horse’s neurological system, which is why preventive care is encouraged. Effective equine vaccines are available commercially. Horse owners should contact their veterinarians if their horses are not up to date on their vaccinations against EEE and WNV. No cases of WNV or EEE have been reported in birds or horses in 2025. 

“It is critical for farmers to remain vigilant and employ standard best practices to prevent exposure to West Nile Virus in horses,” said Ed Wengryn, New Jersey Secretary of Agriculture. “Homeowners should apply the same practices a farmer would in removing standing water from their property to prevent breeding of mosquitoes, control their population growth, and prevent further exposures to mosquito-borne diseases in both farm animals and people.”    

Residents, business owners, and contractors can take steps to reduce mosquito populations on their properties by emptying or changing outdoor standing water at least weekly to stop mosquito breeding. Areas that may need attention include flowerpots, pet food and water dishes, birdbaths, swimming pool covers, clogged rain gutters, plastic wading pools and wheelbarrows, and any containers or trash that may be difficult to see, such as under bushes, homes, or around building exteriors. 

NJDOH can assist health care providers with testing for WNV and other arboviruses, including Powassan, Eastern equine encephalitis, and Jamestown Canyon virus. Testing information is available at nj.gov/health/cd/topics/vectorborne.shtml. 

An interactive vector-borne disease dashboard and weekly reports on WNV-related activity are available on the Department’s website. 

New Jersey's WNV surveillance, control, and prevention activities involve the coordinated efforts of a number of federal, state, and local agencies including: NJDOH, NJDEP, NJDA, the U.S. Centers for Disease Control and Prevention, the New Jersey State Mosquito Control Commission, and local health and mosquito control agencies. 

Resources:  

• NJDOH - West Nile Virus Webpage: gov/health/cd/topics/westnile.shtml
• NJDOH - Interactive Vector-Borne Disease Dashboard: doh.nj.gov/views/public_dashboard/Intro
• NJDOH - Weekly Vector-Borne Surveillance Reports: gov/health/cd/statistics/arboviral-stats
• NJDEP - Mosquito Control Webpage: gov/dep/mosquito
• NJDA - Animal Health Webpage: gov/agriculture/divisions/ah