The virus was found in sentinel chickens kept in New Castle county.

West Nile virus has been detected in Delaware in blood samples taken from sentinel chickens monitored for mosquito-borne diseases, DNREC spokeswoman Joanna Wilson said Friday.

The samples are collected as part of a statewide surveillance program conducted by DNREC’s Mosquito Control Section. So far in Delaware this year, no cases of West Nile virus have been found in horses, humans or wild birds.

The Delaware Division of Public Health Laboratory reported West Nile positive results from seven chickens tested in August. All of the chickens were from New Castle County locations north of the C&D Canal, according to Dr. William Meredith, Division of Fish & Wildlife Mosquito Control Section administrator.

The mosquito control section operates 20 monitoring stations with caged chickens statewide. The sentinel chickens are humanely kept and tended in the field. Sentinel chickens bitten by mosquitoes carrying West Nile or eastern equine encephalitis – both of which can affect humans and horses – develop antibodies that enable them to survive. Their blood is tested every two weeks for these antibodies, which indicate exposure to these viruses.

To reduce mosquito-breeding habitat and chances of disease transmission, Meredith said residents should drain or remove from their outdoor areas all items that collect water, such as discarded buckets or containers, uncovered trash cans, stagnant birdbaths, unprotected rain barrels or cisterns, old tires, upright wheelbarrows, flowerpot liners, depressions in tarps covering boats, clogged rain gutters, downspout extenders and unused swimming pools.

The possibility of mosquito-borne disease transmissions won’t subside until cooler autumn temperatures set in, usually in mid-October and sometimes even later, Meredith said.

To report where mosquito control services are needed in New Castle and northern Kent County, call 30-2836-2555.

South of Dover and in Sussex, call 302-422-1512.