West Nile Virus has been detected in Delaware the first time this year in a sentinel chicken station near Wilmington, the Delaware Department of Natural Resources and Environmental Control announced Tuesday.

The finding was sampled on July 31 by the department’s Mosquito Control Section, and then tested and reported virus positive by the Delaware Public Health Laboratory on Aug. 4.

While there have been no reported West Nile Virus cases in humans this year in the state, Delawareans are reminded that the possibility of contracting mosquito-transmitted diseases, including West Nile Virus and eastern equine encephalitis will continue until colder fall temperatures arrive in mid-October or later.

Blood samples are collected by the Mosquito Control Section each week from early July into October from the state’s outdoor-caged sentinel chickens that are housed and handled at 20 monitoring stations statewide. Sentinel chickens bitten by mosquitoes carrying West Nile Virus or eastern equine encephalitis develop antibodies to these diseases but are otherwise unaffected. Mosquitoes can transmit both diseases to humans and horses.

Most people infected with West Nile Virus do not develop symptoms, but about 20% can develop a mild illness, including fever, body and muscle aches, headache, nausea, vomiting and rash symptoms.  A small number of people can develop serious illness involving neurological problems, paralysis and possibly death.

The Division of Public Health Disease Prevention & Control Section reports that Delaware had one confirmed case of invasive West Nile Virus in 2022 and none so far this year. Eastern equine encephalitis is not as prevalent as West Nile Virus but can present more severe symptoms in humans and horses.

The public is reminded to take precautions to avoid mosquito bites, including wearing light-colored clothing of long-sleeved shirts and long pants when outdoors in mosquito-prone areas; applying insect repellent containing 10 to 30% diethyltoluamide) in accordance with label instructions; and avoiding mosquito-infested areas and at times of peak mosquito activity around dusk, dawn and at night.

More information about mosquitoes and mosquito-borne diseases is available from the following resources:

• For mosquito biology/ecology and control, contact the DNREC 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 Delaware 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.