Mosquito positive for West Nile virus

At least one mosquito has tested positive for West Nile virus in Southern Nevada, prompting health officials once again to urge residents to take precautions when outdoors during early morning or late afternoon hours.

Southern Nevada Health District officials said Wednesday that the positive test came from a mosquito cluster within the 89122 ZIP code area.

Health officials cautioned that just because mosquitoes have tested positive in that area, residents there are not at greater risk of contracting West Nile than others throughout Southern Nevada.

"The thing is mosquitoes are here, and some are West Nile positive,'' said Mark Bergtholdt, environmental health supervisor. "People need to take precaution to prevent mosquito bites.''

Health officials across the nation are giving similar advice.

According to the federal Centers for Disease Control and Prevention's Web site, 308 people have been diagnosed with West Nile across the country this season. The agency reports 11 deaths with five occurring in California alone.

So far this season, the virus has been diagnosed in two Nevadans: a Clark County man younger than 50 and an individual from Pershing County.

Martha Framsted, spokeswoman for the states Health Division, said as of Friday, the Department of Agriculture has tested 203 mosquito pools throughout the state. Three of those pools, two in Churchill County and one in Lyon County, tested positive for West Nile last week.

Last month, a bird in Churchill County and mosquitoes in Elko tested positive.

"We're alert but we haven't seen the problems yet here,'' Bergtholdt said about West Nile activity across the nation. "The West Nile season has just started to get under way. Human cases usually appear this time of year.''

West Nile is considered a late summer and early fall seasonal illness.

It is spread to humans through infected mosquitoes. In most cases, people don't experience any symptoms or become ill. Those who do become ill have symptoms similar to the common cold or flu.

In severe cases, people might suffer from throbbing headache, high fever, neck stiffness and disorientation. They also might go into a coma or suffer paralysis, and death is possible.

Last year, 123 people tested positive for West Nile in Nevada. One person died. Three of those infected lived in Clark County but were believed to have contracted the virus while traveling outside the area, health officials say.

The Health District strongly encourages individuals protect themselves from West Nile and other diseases carried by the mosquito by:

• Applying an insect repellent containing DEET.

• Wearing pants and long-sleeved shirts when outdoors.

• Avoid spending time outside at dusk and dawn, when mosquitoes are most active.

• Eliminate areas of standing water, including bird baths, swimming pools and sprinkler runoff.

In Southern Nevada, green swimming pools are a concern to health officials.

Health District environmental staff say they are responding to more complaints of green pools than last year.

In 2006, the Health District received 745 complaints. Through July, the Health District has received 1,056 complaints this year the Health District has collected about 13,000 mosquitoes for testing.

For more information, call 759-1220 or 1-888-608-4623 statewide, or go to www.cdc.gov.