The detection this week of West Nile virus in sentinel chickens monitored for mosquito-borne diseases by the Delaware Department of Natural Resources and Environmental Control’s Mosquito Control Section serves notice to Delawareans that mosquitoes remain active, especially during unseasonably warm weather the state is experiencing.

Precautions should continue to be taken against mosquito bites that could transmit WNV.

Delaware’s Division of Public Health Laboratory reported seven WNV-positive chickens from five of the Mosquito Control Section’s 20 monitoring stations throughout the state — four in New Castle County and one in Sussex County. Since late July, a total of 19 sentinel chickens have tested WNV-positive this year: 13 from New Castle County, five from Kent County and one from Sussex County. Past north-to-south trends indicate Delaware could see a possible increase in WNV-positive findings in downstate sentinel chickens in the coming weeks. Eastern equine encephalitis, another mosquito-borne disease affecting people and horses, was found at a sentinel chicken station in southwestern New Castle County in July. No human cases of WNV or EEE have been reported this year in Delaware.

The recent WNV findings in sentinel chickens prompted the Mosquito Control Section to increase mosquito population surveillance in areas surrounding the stations where the chickens tested positive, to take control actions including aerial spraying and residential fogging. In addition, the section encourages residents to use repellent containing DEET, to wear long sleeve shirts and long pants outdoors and avoid mosquito-infested areas during times of peak mosquito activity.

To reduce mosquito-breeding habitat, the Mosquito Control Section advises residents to drain or remove 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.

Mosquito Control also encouraged residents to report intolerable numbers of biting mosquitoes by calling the office. Staff answers phones between 8 a.m. and 4 p.m. Mondays through Fridays. 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: 836-2555.

— Milford office, serving Sussex and southern Kent counties: 422-1512.

— Mosquito biology/ecology and control, contact the Mosquito Control Section’s Dover office at 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 836-2555; for downstate areas south of Dover, contact Mosquito Control’s Milford field office at 422-1512.

— WNV or EEE in humans and related medical issues, contact the Delaware Division of Public Health at 888-295-5156.

— WNV or EEE in horses and equine vaccines, contact the Department of Agriculture’s Poultry and Animal Health Section at 698-4500 or 800-282-8685.