Two New Jersey residents have died of West Nile virus this year, bringing the number of reported deaths in the U.S. to five this mosquito season.
New Jersey Department of Health officials announced an additional six confirmed cases in the state. Those cases were reported in Bergen, Camden, Cumberland, Hudson, Mercer and Middlesex counties.
This brings New Jersey’s total to eight cases of West Nile virus, seven of which required hospitalization. Three asymptomatic blood donors also tested positive for the virus, according to the department.
West Nile virus has been detected in the U.S. for the last 25 years, but health officials say it’s shown up earlier than usual in New Jersey this year, with the first two human cases reported in the state in early July.
Another, rarer mosquito-spread illness, Eastern equine encephalitis, has also returned this year, with the state’s first confirmed human infection since 2019.
West Nile virus and Eastern Equine Encephalitis are typically contracted by humans through the bite of a mosquito that has previously fed on an infected bird or other animal.
That case involved an Atlantic County patient under 18 years of age who was hospitalized, and later discharged. The last time cases of Triple E were reported in humans was in 2019, when the state reported four cases.
A horse with symptom-onset that tested positive for EEE was also reported in early August in Atlantic County.
Eastern equine encephalitis, commonly called Triple E or sleeping sickness, is a disease caused by a zoonotic mosquito-vectored Togavirus that is present in North, Central, and South America, and the Caribbean.
Rockaway Township officials in Morris County recently alerted residents that Triple E was found in a mosquito pool in the northern part of town near Valley Road.
Among the eight confirmed West Nile cases in New Jersey so far, seven led to hospitalizations with a neuroinvasive disease − including encephalitis, a swelling of the brain − or meningitis, the swelling of the lining surrounding the brain and spinal cord, the state said.
Nearly 300 cases of West Nile virus disease have been reported across the country this year, according to the CDC. Last year, Some 14 cases of West Nile virus were reported in New Jersey, and one death.
In New York, there have been 10 cases of West Nile virus this year, according to the CDC. The largest share of cases is in Texas, where just over 40 cases have been reported.
“All New Jerseyans should be aware of the potential significant impacts from mosquito-borne illnesses, especially West Nile virus and Eastern Equine encephalitis,” said NJ Health Commissioner Kaitlan Baston. “The best way to prevent these diseases is to avoid mosquito bites by using insect repellent, protective clothing or gear, and avoiding peak mosquito hours.”
During routine testing of blood donations, three asymptomatic blood donors from Bergen, Passaic, and Somerset counties were found to have tested positive for West Nile virus. These comprehensive tests ensure that all blood donations are screened for West Nile virus, significantly reducing the risk of contracting West Nile virus through blood transfusions and keeping the blood supply safe.
Residents, business owners, and contractors can also take steps to reduce mosquito populations on their properties by emptying or changing standing water outdoors at least once a week to stop mosquito breeding. Areas that may need attention include flower pots, pet food and water dishes, birdbaths, pool covers, clogged rain gutters, plastic wading pools and wheelbarrows, and any containers or trash that may be difficult to see under shrubs, houses, or around the exteriors of buildings.
Most people infected with West Nile virus or EEE have no symptoms. Those who do, symptoms include fever, chills, body aches, and joint pains. Rarely, people may develop a serious neurological disease, often presenting as meningitis or encephalitis. Symptoms of a serious illness include fever, severe headache, stiff neck, vomiting, diarrhea, seizures, behavior changes/confusion, weakness of the limbs, and fatigue.
Older adults and people with weakened immune systems are at higher risk of developing severe disease. Specific lab tests are needed to confirm WNV and EEE, so anyone with symptoms after a mosquito bite should contact their healthcare provider.
Recovery from a serious illness can take several weeks or months, and some effects may be permanent. According to the Centers for Disease Control and Prevention, about one-third of all people with Eastern Equine Encephalitis and 1 in 10 people with severe WNV neurological disease die.
State and county mosquito control programs are working together to minimize the potential transmission of these diseases to humans, but mosquito populations have not yet peaked. The state typically sees most human cases of mosquito-borne diseases between mid-August and mid-to-late September, but the season can extend into October and even early November, depending on weather conditions.
“There are many simple things the public can do to help control the mosquito population,” said Environmental Protection Commissioner Shawn M. LaTourette. “The main sources of mosquitoes in the home are usually small water-holding places and containers that could easily go unnoticed, such as tarp folds, pet water bowls, flower pots, recycling bins, children’s toys, buckets, and even extension gutters. Property owners should keep an eye out for these sources and conduct weekly inspections to ensure they are free of standing water. Some species can travel miles from their breeding habitat, so if you have problems with mosquitoes, contact your county mosquito control program for advice and help.”
September marks the 25th anniversary of the emergence of West Nile virus in the United States, and New Jersey had its first human case in 2000. Currently, West Nile virus is the most common mosquito-borne disease acquired locally.
The first case of WNV was reported this year in early July, which is earlier than typically seen in New Jersey. In a typical year, 13 human infections with West Nile virus are reported. Last year, New Jersey had 14 human cases of WNV and one death.
This year, the detection of West Nile virus in mosquitoes has also been considerably earlier than expected. West Nile virus has been detected in 702 mosquito groups, which is higher than average and has been found in every county in New Jersey except Cumberland. Detections of WNV in mosquitoes are highest in the northeastern part of the state, particularly in Bergen, Hudson, Middlesex, and Union counties. EEE has been detected in mosquitoes in Cape May, Gloucester, Hunterdon, Monmouth, Morris, and Union counties.
West Nile virus and EEE also affect horses, and EEE has a significantly higher risk of death in horses than West Nile virus infection, according to the New Jersey Department of Agriculture. EEE and WNV infections in horses are not a significant risk factor for human infection because horses (like humans) are “dead-end” hosts for the virus. Effective equine vaccines for EEE and WNV are commercially available. Horse owners should contact their veterinarians if their horses are not up to date on their EEE and WNV vaccinations.