The New Jersey Departments of Health (NJDOH), Environmental Protection (NJDEP), and Agriculture (NJDA) are urging state residents to take precautions this summer to protect themselves from all mosquito-borne diseases including Eastern Equine Encephalitis, a rare virus transmitted to people and horses by the bite of an infected mosquito.
The DOH has confirmed the first human case of Eastern Equine Encephalitis this summer in an elderly Somerset County man. The man was hospitalized but has been discharged for continued rehabilitation care.
To date, Eastern Equine Encephalitis has been detected in 22 mosquito samples and in three horses in the southern and eastern parts of the state.
Most persons infected with Eastern Equine Encephalitis have no apparent illness, however some can be very ill. Severe cases of Eastern Equine Encephalitis (involving encephalitis, an inflammation of the brain) begin with the sudden onset of headache, high fever, chills, and vomiting 4 to 10 days after a mosquito bite. The illness may then progress to disorientation, seizures, or coma.
Eastern Equine Encephalitis is one of the most severe mosquito-transmitted diseases in the U.S. About one-third of people with Eastern Equine Encephalitis die from the disease and there is significant brain damage in most survivors. While there is a vaccine for horses, there is no vaccine for people.
Clinicians are asked to consider Eastern Equine Encephalitis in people with compatible symptoms and contact their local health department to ask about testing for the virus. Laboratory testing for Eastern Equine Encephalitis is only available at the State Public Health and Environmental Laboratories.
“Thankfully, human infections with Eastern Equine Encephalitis are rare, but we are concerned when we start seeing a lot of activity in mosquitoes and horses since this is a warning sign of risk for human infection,” said Acting Health Commissioner Judith Persichilli. “Anyone who is concerned they may have Eastern Equine Encephalitis should contact their health care provider right away.”
Reducing exposure to mosquitoes is the best defense against infection with Eastern Equine Encephalitis and other mosquito-borne viruses. There are several steps you and your family can take to prevent and control mosquito-borne diseases.
Prevent Mosquito bites:
- Use repellent: When outdoors, use insect repellent containing DEET, picaridin, IR3535 or oil of lemon eucalyptus on exposed skin and/or clothing. The repellent/insecticide permethrin can be used on clothing to protect through several washes. Always follow package directions. Insect repellent should not be used on children less than 2 months old and oil of lemon eucalyptus should not be used on children less than 3 years
- Wear protective clothing: Wear long sleeves/pants when weather permits
- Install and repair screens: Have secure, intact screens on windows and doors to keep mosquitoes out and use air conditioning if you have it
NJDEP works with county mosquito control agencies to conduct testing for viruses in mosquitoes each year. NJDEP is working closely with county mosquito-control agencies, expanding trapping and testing mosquitoes for Eastern Equine Encephalitis this season.
“Controlling New Jersey’s mosquito population is a major part of protecting our public health,” said DEP Commissioner Catherine R. McCabe. “Through strong state and local partnerships, we are able to greatly reduce the risk of mosquito-borne illnesses. The public has to do its part, too. Dumping out standing water on your property goes a long way toward reducing mosquito bites by limiting where they grow. Anywhere that collects water can breed mosquitos, so checking flower pots, pet food and water dishes, birdbaths, swimming pool covers and other places can reduce the risk of mosquito bites and the illnesses they can carry.”
In horses, Eastern Equine Encephalitis causes inflammation of the brain tissue, and produces clinical signs such as fever, anorexia, depression, hypersensitivity, aimless wandering, head pressing, circling, paralysis and death. Eastern Equine Encephalitis infections in horses are not a significant risk factor for human infection because horses (like humans) are considered "dead-end" hosts.
“Horse owners need to be vigilant in vaccinating their animals against diseases spread by mosquitoes,” said New Jersey Secretary of Agriculture Douglas H. Fisher. “Vaccinated animals are much less likely to contract deadly diseases such as Eastern Equine Encephalitis. Vaccination is the most effective strategy and effective equine vaccines are available commercially. Horse owners may also consider housing animals in screened barns during peak mosquito hours and using mosquito repellents and fans.
Mosquitoes can lay eggs even in small amounts of standing water. You and your family can take the following steps to limit mosquitoes on your property and keep them from laying eggs near you:
- Empty standing water from flower pots, buckets, barrels, and tires. Change the water in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out. Empty children’s wading pools and wheelbarrows and store on their side after use.
- Dispose of water-holding containers that have accumulated on your property, especially discarded tires
- Drill holes in the bottom and elevate recycling containers that are left outdoors
- Clean up any trash or leaves that may be around your home or in rain gutters at least once a year
- Aerate ornamental pools or stock them with fish
- Clean and chlorinate swimming pools that are not being used. Mosquitoes can even breed in the water that collects on pool covers
- Use landscaping to eliminate standing water that collects on your property
This July, the Department of Health launched its Fight the Bite NJ awareness campaign to continue to promote awareness and provide education throughout the state on how to avoid mosquito-borne illness. Social media and online advertisements encourage residents to take steps to protect against mosquito bites.
Clinicians are required to report human Eastern Equine Encephalitis cases and other arboviruses to the local health department where the person resides within 24 hours of diagnosis (www.localhealth.nj.gov). The local health department can assist clinicians with EEE testing at the New Jersey Public Health and Environmental Laboratories.
Residents who need assistance controlling mosquitoes around their home can call their county mosquito control agency or 888-666-5968.
Eastern Equine Encephalitis, like other viral diseases affecting a horse’s neurological system, must be reported to the state veterinarian at 609-671-6400 within 48 hours of diagnosis.
NJDOH posts a weekly Vector-borne Disease Surveillance report at https://www.nj.gov/health/cd/statistics/arboviral-stats/