First Cases of West Nile Virus Reported in New Jersey

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

TRENTON - The New Jersey Department of Health has confirmed the state's first human cases of West Nile virus (WNV) this year.

Two residents (ages 70+ years and <18 years) tested positive for West Nile virus neuroinvasive disease in Union and Middlesex counties with symptoms reported the first week of July. Both individuals were hospitalized and have since been discharged. An additional report of an asymptomatic WNV-positive blood donor was reported in a Somerset County resident.

WNV cases with symptom onset in early July are earlier than what is typically seen in New Jersey, where most WNV cases occur between mid- August and mid-September. In a typical year, there are 13 human WNV infections reported. Last year, New Jersey had 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 JerseyHealth 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."

To protect against mosquito-borne diseases, residents should:

• Wear EPA-registered insect repellant.
• Avoid being outdoors during dawn and dusk when mosquitos are most active.
• Wear long sleeves and long pants and covering exposed skin.
• Cover cribs, strollers, and baby carriers with mosquito netting.
• Repair holes in screens to keep mosquitoes outside and use air conditioning when possible or ensure you have well-fitted screens.

For many people, WNV causes asymptomatic infection or a mild to moderate illness, typically with a fever. People over age 50 and people with weakened immune systems are at greater risk of developing severe illness.

About one in 150 people will develop a more severe form of the disease, with symptoms such as a severe headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. WNV can even lead to death in severe cases.

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 for it. The best way to prevent the disease is to avoid mosquito bites.

"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."

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

This year, the detection of WNV in mosquitoes has also been considerably earlier than expected. WNV has been detected in 286 mosquito pools, which is higher than average detections at this time of year and has been found in all New Jersey counties except Cumberland. WNV detections in mosquitoes are highest in the northeastern part of the state, particularly in Middlesex, Hudson, Bergen, and Union counties.

Apart from WNV, which is the most commonly reported locally-acquired mosquito-borne disease, EEE, which is a rare, but severe infection, has been detected in Cape May, Morris, and Union counties. The state and county mosquito control programs are working together to minimize potential transmission of these diseases to humans, but it is still early in the arbovirus surveillance season, and mosquito populations have not yet peaked.

In addition to potentially harming humans, WNV can harm certain birds and animals as well, including horses. WNV affects a horse's neurological system, which is why preventive care is encouraged. Effective equine vaccines for EEE and WNV 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 horses in 2024.

"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, 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 and Eastern equine encephalitis. 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: 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