The Santa Clarita Valley has seen 17 cases of West Nile virus so far this season – all of them in birds.

Thirteen dead crows have been found to be infected, in a fairly even distribution across the valley.

Sentinel chickens

Last week, four sentinel chickens that the Greater L.A. County Vector Control District keeps and monitors in Newhall tested positive.

Like the proverbial canary in the coal mine, “sentinel” chicken flocks are kept in cages and observed over time. West Nile virus doesn’t manifest itself the same way in chickens as it does in crows – chickens don’t usually drop dead – but the chickens produce antibodies that indicate they’ve been bitten by sick mosquitoes.

The positive chicken readings show that “residents this summer are at increased risk of WNV infection from mosquito bites,” according to Vector Control.

Countywide, the virus has been detected in 138 mosquito samples within the Vector Control District’s service area. In addition, 33 dead birds and five sentinel chickens (including the four in Newhall) have tested positive.

West Nile virus is primarily found in birds, and is transmitted between birds and to people and horses by mosquito bites.

Vector Control says:

Mosquitoes need standing water to lay their eggs. Simple as that.

Look around where you live. Almost anything can hold water: Buckets, plant saucers, old tires, a fountain, even a swimming pool.

Identify all the containers that can hold water. And then either dump and drain the water once a week or throw away the containers.

If you want a good night’s rest or a bite-free day, get rid of all containers that can hold water.

Residents experiencing mosquito problems during the day or at night, even after dumping all standing water, can receive help from the Greater Los Angeles County Vector Control District at (562) 944-9656 or visit www.ReportMosquitoes.org.