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Delawareans warned to protect themselves from mosquito bites

Betsy PriceHeadlines

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DNREC is warning state residents to avoid mosquito bites and to empty outdoor vessels that might hold water for mosquito breeding.


With West Nile Virus showing up more frequently in sentinel chickens, the state is warning residents to try to avoid being bitten by mosquitoes.

The Delaware Department of Natural Resources and Environmental Control said that the fall is the most likely time for the virus to be transmitted through a mosquito bite to humans. Cold weather usually ends the threat.

The virus can be fatal to some people. A Kent county man was infected with the virus this summer, the first since 2018.

Common-sense precautions when outdoors in mosquito-prone areas include wearing long-sleeved shirts and long pants, applying insect repellent containing 105 to 30% diethyl toluamide (DEET) or other EPA-approved insect repellents in accordance with label instructions and avoiding mosquito-infested areas and times of peak mosquito activity around dusk, dawn and at night, DNREC said.

The state keeps chickens at 20 stations around Delaware to test them and West Nile and Eastern Equine Encephalitis, the primary mosquito-transmitted human health threats in Delaware.

Statewide, 40 sentinel chickens have tested positive for West Nile with 25 occurring in the last few weeks. That involved 32 chickens in New Castle County from six stations, four chickens in Kent County from two stations, and four chickens in Sussex County from two stations.

Equine Encephalitis has not been found this year in the sentinel chickens.

More measures can be taken by property owners to reduce mosquito-breeding habitat and mosquito populations and the chances for disease transmission.

DNREC’s Mosquito Control section recommends draining or removing outdoor items that collect water, a lengthy list that includes discarded buckets or containers, uncovered trashcans, stagnant birdbaths, uncovered rain barrels or cisterns, old tires, upright wheelbarrows, flowerpot liners and saucers, depressions in boat tarps, clogged rain gutters, corrugated downspout extenders and unused swimming pools.

There are no human vaccines for WNV or EEE. About 80% of people infected with WNV show no symptoms, while about 20% of those infected will develop mild symptoms such as low fever, headache, body aches, a skin rash on chest or back and swollen lymph glands.

Only about one in 150 people infected with WNV might develop severe infection indicted by high fever, disorientation, tremors or convulsions, encephalitis or meningitis, all possibly leading to hospitalization and very rarely death. Some survivors of severe cases of WNV can have long-lasting medical complications, including lingering paralysis.

In response to West Nile tests, the Mosquito Control section has increased mosquito population surveillance efforts in the vicinity of virus-positive findings and initiated targeted mosquito control actions as warranted, based on biting mosquito species and the numbers of them encountered.

Additional information about mosquitos and mosquito-borne diseases is available from the following resources:

  • For mosquito biology/ecology and control, contact the Mosquito Control section office in Dover at 302-739-9917.
  • For requests for mosquito relief in upstate areas from Dover north, contact Mosquito Control’s Glasgow field office at 302-836-2555.
  • For requests for mosquito relief in downstate areas south of Dover, contact Mosquito Control’s Milford field office at 302-422-1512.
  • For animal health questions, contact the Delaware Department of Agriculture’s Poultry and Animal Health Section at 302-698-4500.
  • To report suspected cases of human WNV, call the Division of Public Health Office of Infectious Disease Epidemiology toll-free at 888-295-5156.
  • For more information on West Nile Virus or Eastern Equine Encephalitis, visit www.cdc.gov/ncidod/dvbid/westnile/index.htm.

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