DNREC’s Mosquito Control Section announces expanded detection of Eastern Equine Encephalitis

Continued awareness and precautions encouraged

The logo for the Department of Natural Resources and Environmental ControlDOVER (Sept. 20, 2018) – The recent detection of Eastern Equine Encephalitis (EEE) in sentinel chickens monitored for mosquito-borne diseases by the DNREC Division of Fish & Wildlife’s Mosquito Control Section reinforces the fact that mosquitoes remain active and that precautions should continue to be taken to avoid mosquitoes whose bites could transmit EEE and other mosquito-borne diseases.

Test results reported to the Mosquito Control Section last week by the Delaware Division of Public Health Laboratory indicated EEE-positive chickens from three additional stations of the 20 stations monitored by the Mosquito Control Section throughout the state. Two of these positive stations were in New Castle County and one in Sussex County, increasing the total number of EEE-positive sentinel chicken stations this year to six: three in New Castle County and three in Sussex County. This higher-than-average detection rate for EEE suggests increased EEE activity and distribution in Delaware.

Eastern Equine Encephalitis is a rare, but potentially fatal, viral disease spread by mosquitoes, and is considered one of the more serious mosquito-borne illnesses. Although there is an EEE vaccine for horses, an EEE vaccine is not available for people. No human cases of EEE have been reported to date this year in Delaware.

Anyone in an area where the virus is circulating can be infected with EEE. The risk is highest for people exposed to high numbers of mosquito bites, including people who live in, visit, or work outside in areas with high mosquito populations where there is greater exposure to potentially infected mosquitoes. Those over age 50 and under age 15 appear to be at greatest risk for developing severe disease when infected with EEE.

While most patients infected with EEE have no apparent illness, severe cases of EEE (involving encephalitis, an inflammation of the brain) begin with the sudden onset of headache, high fever, chills, and vomiting. The illness may then progress into disorientation, seizures, or coma. Symptoms of EEE often appear four to 10 days after being bitten by an infected mosquito. Approximately 33 percent of EEE cases lead to death, and many of those who do survive experience significant brain damage. There is no specific treatment for EEE; care is based on symptoms. If you think you or a family member may have contracted EEE, it is important to consult your health care provider for proper diagnosis.

In response to DNREC’s recent EEE detections, along with ongoing West Nile virus activity, the Mosquito Control Section will increase mosquito population surveillance in areas where these detections have occurred and take mosquito control actions as warranted to include possible aerial spraying and/or fogging with a spray truck. However, the best protection to lessen the chance of contracting a mosquito-borne disease is to avoid mosquito bites by:

  • Properly using insect repellent containing DEET whenever outdoors;
  • Covering up exposed skin as much as possible by wearing long-sleeved shirts and pants; and
  • Avoiding known high mosquito population areas or being outside during times of peak mosquito activity, typically dawn and dusk.

In addition to avoiding mosquito bites, the Mosquito Control Section advises residents to also reduce mosquito breeding habitat on their individual properties and communities/neighborhoods by draining or removing items that collect water, such as discarded buckets or containers, uncovered trash cans, stagnant birdbaths, unprotected rain barrels or cisterns, old tires, upright wheelbarrows, flower pot liners, depressions in tarps covering boats, clogged rain gutters, corrugated downspout extenders and unused swimming pools.

The Mosquito Control Section also encourages residents to report intolerable numbers of biting mosquitoes by calling the numbers below between 8 a.m. and 4 p.m. Monday through Friday. Callers after business hours or during weekends or holidays should leave their name, phone number, address and a brief message.

  • Glasgow Office, serving New Castle County and northern Kent County including the Dover area: 302-836-2555
  • Milford Office, serving Sussex and southern Kent counties: 302-422-1512

For more information about:

  • Mosquito biology/ecology and control – Contact the Mosquito Control Section’s Dover office at 302-739-9917.
  • Reporting WNV-suspect wild birds, or for requests for mosquito relief – For upstate areas from Dover north, contact Mosquito Control’s Glasgow field office at 302-836-2555; for downstate areas south of Dover, contact Mosquito Control’s Milford field office at 302-422-1512.
  • WNV or EEE in humans and related medical issues – Contact the Delaware Division of Public Health at 888-295-5156.
  • Animal health questions should be directed to the Delaware Department of Agriculture at 800-282-8685 (Delaware only) or 302-698-4500. Ask for the Poultry and Animal Health Section.
  • For more information on West Nile Virus or Eastern equine encephalitis – Visit the CDC website, www.cdc.gov/ncidod/dvbid/westnile/index.htm.

Contact: Joanna Wilson, DNREC Public Affairs Office, 302-739-9902

Vol. 48, No. 253