PO Box 360
Trenton, NJ 08625-0360

For Release:
May 23, 2017

Cathleen D. Bennett

For Further Information Contact:
Office of Communications
(609) 984-7160

Taking Precautions Against Mosquitoes Can Prevent Diseases like Eastern Equine Encephalitis

The New Jersey Departments of Health (DOH), Environmental Protection (DEP) and Agriculture (NJDA) recommend that state residents take precautions to protect themselves from all mosquito-borne diseases, including Eastern Equine Encephalitis (EEE).

The EEE virus is transmitted to people and horses by the bite of an infected mosquito. Most people infected with EEE have no apparent illness, but some can become very ill. Severe cases involving encephalitis, an inflammation of the brain, begin with the sudden onset of symptoms that include headache, high fever, chills and vomiting within 4 to 10 days after a mosquito bite. The illness may progress into disorientation, seizures or coma.

EEE is one of the most severe mosquito-transmitted diseases in the U.S. Approximately one-third of people with EEE 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.

A fatal EEE case was reported last year in a Passaic County resident, the first case of human EEE reported in New Jersey since 2003. By taking steps to prevent mosquito bites and protect horses, residents can dramatically decrease their risk of exposure.

“Reducing exposure to mosquitoes is the best defense against infection with EEE and other mosquito-borne viruses,” Health Commissioner Cathleen D. Bennett said. “While we are always concerned about more common mosquito-borne diseases like West Nile virus and travel-associated viruses like Zika and dengue, we also need to be vigilant for less common but severe viruses like EEE. Anyone who is concerned they may have EEE should contact their healthcare provider.”

DEP works with county mosquito control agencies to conduct testing for viruses in mosquitoes each year. Mosquito control agency efforts to improve water management help to reduce mosquito breeding sites. EEE is not usually detected in mosquitoes or horses in the northern part of the state. However in 2016, EEE was detected in two horses in Morris County, one horse in Ocean County and one horse in Passaic County. DEP is working closely with county mosquito control agencies, particularly in the northern part of the state, to expand trapping and testing mosquitoes for EEE this season.

“Our goal is to find the virus in mosquitoes so preventative control measures can be performed to minimize the threat of disease transmission,” DEP Commissioner Bob Martin said.

In horses, EEE causes inflammation of the brain tissue, and produces clinical signs such as fever, anorexia, depression, hypersensitivity, aimless wandering, head pressing, circling, paralysis and death. EEE infections in horses are not a significant risk factor for human infection because horses (like humans) are considered "dead-end" hosts, meaning they are unable to maintain high enough virus levels in the bloodstream to infect a mosquito.

There are several approaches you and your family can use 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 provide protection through several washes. Always follow the directions on the package. Insect repellent should not be used on children less than 2 months of age and oil of lemon eucalyptus should not be used on children less than 3 years.

  • Wear protective clothing: Wear long sleeves and 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.

Mosquitoes can lay eggs even in small amounts of standing water. You can take the following steps to limit mosquitoes on your property and keep mosquitoes 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.

Residents who need assistance controlling mosquitoes around their home can call their county mosquito control agency or 888-666-5968.

For horse owners, preventing transmission to horses from mosquitoes has improved vastly in the last decade, thanks to the development of a vaccine. Vaccination is the most effective strategy and effective equine vaccines are available commercially. Horse owners also may consider housing animals in screened barns during peak mosquito hours and using mosquito repellents and fans.

“Horse owners need to be vigilant in vaccinating their animals against diseases spread by mosquitoes,” Secretary of Agriculture Douglas H. Fisher said. “Vaccinated animals are much less likely to contract deadly diseases such as EEE.”

Clinicians are required to report human EEE 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.

EEE, like other viral diseases affecting a horses’ neurological system, must be reported to the state veterinarian at 609-671-6400 within 48 hours of diagnosis. The New Jersey Animal Health Diagnostic Laboratory is available to assist with EEE testing and can be reached at 609-671-6999 or via email at jerseyvetlab@ag.state.nj.us.

More information:

DOH: www.nj.gov/health/cd/topics/eee.shtml

DEP: www.nj.gov/dep/mosquito

NJDA: www.nj.gov/agriculture/divisions/ah/diseases/diseaseworksheets.html

Follow the New Jersey Department of Health on Twitter @njdeptofhealth, Facebook /njdeptofhealth, Instagram @njdeptofhealth and Snapchat @njdoh.

For more information, visit our homepage at nj.gov/health.

Last Reviewed: 6/5/2017