EGG-ZACT SCIENCE CHICKENS WATCH OUT FOR VIRUS.

Byline: Charles F. Bostwick Staff Writer

LANCASTER - Antelope Valley's first line of defense went on duty Tuesday against the potentially fatal West Nile virus.

Forty-eight white leghorn chickens were parceled out to coops at homes and at water and road department offices in Lancaster, Palmdale, Quartz Hill and Rosamond.

Every two weeks, an Antelope Valley Mosquito and Vector Control District worker will poke each bird on its comb to get a blood sample to test for signs of West Nile virus, spread by mosquito bites.

Unlike people, horses and other birds, chickens don't get sick from West Nile virus.

``They don't show symptoms. They don't get sick from it and they don't die from it,'' said Karen Mellor, the vector control district's entomologist.

Known as ``sentinel'' chickens, the birds are going out a month earlier than normal at the recommendation of state health officials.

West Nile virus has already shown up elsewhere in Southern California. Mosquitoes carrying the virus were found in January in Orange County, a dead crow with the disease was found four weeks ago in Santa Clarita, and sentinel chickens in Ontario tested positive last week.

West Nile virus last year infected more than 300 Los Angeles County residents, including 190 who became ill enough to be hospitalized and 13 who died. The largest outbreak was in the San Gabriel Valley. The human case closest to the Antelope Valley occurred in Saugus.

While no human cases were reported last year in the Antelope Valley, two horses became sick - one so seriously it was euthanized.

Chickens have been set out annually around the Antelope Valley since the late 1980s checking for mosquito-borne diseases - originally St. Louis encephalitis and Western equine encephalitis, lately West Nile virus.

The first time that any showed signs of any disease was last year, when 13 chickens tested positive for West Nile virus.

Eight flocks are being set out this year, one more than last summer. The extra coop is in east Lancaster, where one of the infected horses was from last year.

While mosquitoes are not commonly regarded as desert dwellers, district employees say people provide them with breeding sites. They breed in unmaintained swimming pools and roadside ditches, as well as in water that runs off lawns and collects in gutters and basins.

Heavy winter rains have formed puddles and shallow ponds around the valley, but that is not expected to add to the mosquito problem, officials said.

``A lot of those places are going to dry up. All our normal sources, they will still be with us,'' said Keith White, the district's field supervisor.

The district supplies feed for the chickens kept at people's homes. The people get the eggs.

``We supply feed for them. They get the eggs and after the season they get the chickens if they want them. If not, we'll take them,'' White said.

First discovered in the United States in New York in 1999 and spread steadily westward since, the virus is transmitted by mosquitoes that bite infected birds and then pass it on to people or other animals.

Dead birds are an early sign of the arrival of the virus, which is not spread by person-to-person contact - though it has been spread by breast- feeding and blood transfusions - or directly by birds.

Charles F. Bostwick, [phone]

chuck.bostwick(at)dailynews.com

AT RISK

--People at the highest risk of life-threatening disease are over age 50 or have weak immune systems from another illness.

--Most mosquitoes do not have West Nile virus.

--Eighty percent of infected people have no symptoms. People typically develop symptoms between three and 14 days after they are bitten by an infected mosquito.

--Mild symptoms include fever, headache, body aches, vomiting and sometimes swollen lymph glands or a skin rash. They pass on their own.

--Of those infected, one in 150 can develop severe symptoms or even die. Severe symptoms can include high fever, neck stiffness, tremors, muscle weakness, vision loss, numbness and paralysis. Neurological effects may be permanent.

--The best way to protect against the disease is to protect against mosquito bites.

Source: Los Angeles County Health Department, Centers for Disease Control and Prevention 

MOSQUITO TIPS

To reduce exposure to the virus, health officials suggest residents follow the precautions recommended for all mosquito-borne diseases:

--Get rid of standing water, where mosquitoes can breed. Empty all small containers at least once a week, keep pools and spas chlorinated or drained, repair all water leaks and avoid overwatering. Anything that holds water longer than a week is a potential mosquito producer.

--Get mosquito-eating fish (Gambusia affinis) for free from the mosquito district if you have sources that cannot be drained, such as fish ponds and large horse troughs.

--Wear long-sleeve shirts and pants and use mosquito repellent containing DEET when outdoors during dusk and dawn.

--Keep tight-fitting screens on doors and windows to prevent mosquitoes from entering homes.

--Horse owners should make sure their horses are properly vaccinated.

--Report stagnant pools and other backyard sources to the mosquito district so technicians can treat them.

The mosquito district can be reached at [phone]. Its Web site is at www.avmosquito.org. Crows and ravens that have recently died - without obvious trauma - can be reported by calling (877) WNV-BIRD. Use gloves, a shovel or an inverted trash bag to pick up any dead bird.

Source: Antelope Valley Mosquito and Vector Control District

CAPTION(S):

3 photos, 2 boxes

Photo:

(1 -- 2 -- color) White leghorn chickens, above, were distributed throughout the Antelope Valley to be tested periodically for West Nile virus. At left, a blood sample is taken from a chicken.

(3) Antelope Valley Mosquito and Vector Control District entomologist Karen Mellor and lab technician John Michalski draw blood from a sentinel chicken on Tuesday to test for the West Nile virus.

Jeff Goldwater/Staff Photographer

Box:

(1) AT RISK (see text)

(2) MOSQUITO TIPS (see text)