County Vector Control workers watch for West Nile virus through flocks of sentinel hens
It's a good gig for a hen, this sentinel thing. There's plenty of food and fresh water. Clean nest boxes and a nice house in the country to share with a few friends. No bothersome roosters. All the people ask in return is a little blood every two weeks.
Researchers test the blood to determine whether mosquito-borne diseases such as equine encephalitis or West Nile virus have entered Jackson County.
Hopefully we see it in a chicken before we see it in a human, said Jim Clover. The Applegate biologist drew blood from the county's four flocks of sentinel chickens on Monday. The flocks are stationed around the county in areas where there's abundant standing water and plenty of birds.
The birds are the ones who are going to bring the virus in, Clover said. They're the movers of the virus.
— The sentinel chickens are one of the tools that Jackson County Vector Control District uses in its annual campaign against mosquitoes. Workers also spray insecticide in mosquito-ridden areas, apply chemicals on standing water to inhibit mosquito growth, and distribute fish that eat mosquito larvae.
Mosquitoes that bite infected birds can pass the virus to other birds ' and conceivably to humans. That hasn't happened yet, but scientists expect West Nile virus to arrive in Oregon sometime this summer.
Most people and animals infected with the virus have only a mild illness or no symptoms. In rare cases, the virus can cause a more serious condition called encephalitis, an inflammation of the brain. the end of 2002, health officials tallied about 4,000 reported human cases and 277 deaths in the 44 states where it was detected.
This spring the virus has been found in 26 states, but only as far west as Colorado and Wyoming, according to statistics from the federal Centers for Disease Control and Prevention.
Interest in mosquito control rises every year in June as insect populations soar, said Eugene Papineau, who manages the district. But with West Nile virus making so much news in recent years, local residents have been calling Vector Control in record numbers this spring. midday Monday, Papineau said the district had fielded 2,628 calls in 2003, nearly 100 more than it received during the entire year of 2002.
Papineau said many regular customers call every year to request aerosol spraying around their home, but the number of new callers has grown dramatically this year.
People are really worried, Papineau said. They want us to do something (to protect them) right away.
The calls for mosquito fish have doubled or tripled, he said.
People concerned about their health also seem more willing to complain about standing water on neighbors' property that might provide breeding grounds for mosquitoes that could spread the West Nile virus if it arrives here.
Swimming pools that are no longer chlorinated are a huge source of mosquitoes, Papineau said. A single pool can produce millions of mosquitoes during the season.
A lot more people are turning in their neighbors, he said. We're getting a lot more calls about unkempt swimming pools.
With so many people seeking help, some may have to wait several weeks for one of the district's four spray trucks to make an appearance, Papineau said. The district's boundaries encompass all of Jackson County, and workers sometimes have to drive long distances between customers.
If West Nile virus surfaces, Papineau said the district probably will have to fight mosquitoes with the tools it has. Budget shortages at every level of government make extra resources unlikely to appear.
It's going to be an interesting summer for us, he said.
Reach reporter Bill Kettler at 776-4492, or e-mail
What you can do to keep mosquito numbers down
Mosquitoes don't need much water to breed, so it's important to eliminate all sources of standing water to keep their numbers down.
Jackson County Vector Control offers this advice:
Empty stagnant water in bird baths, plant pots, rose cuttings, drip trays, small wading pools, pet dishes and other containers once a week.
Eliminate water-holding tree stumps. Fill holes in trees with soil or sand.
Store small boats upside down or cover them to keep out rain and water from sprinklers.
Repair leaky outdoor faucets.
Cover unused swimming pools to prevent accumulation of leaves and debris. Be sure pool covers do not hold pockets of water.
Remove old tires, buckets, cans, drums, bottles or other containers that can hold water.
Cover trash containers.
Inspect rain gutters and downspouts and remove leaves and other debris.
Plant mosquito fish in water troughs and ornamental ponds.
Clean flat roofs and air conditioner drains frequently.
Fill or drain any low spots in your yard.