Two more cases of West Nile confirmed

Beth Slovic

Monday, Aug. 23, 2004 | 11:06 a.m.

Two more cases of suspected West Nile virus have been confirmed in Clark County residents, the health district announced Friday.

That raised the total confirmed cases in the county to four since the mosquito-borne illness was discovered in the state this summer, and there are an additional nine probable cases, instances in which patients' symptoms and preliminary tests indicate West Nile infection. The final test results are not back yet.

The health district will not release the ZIP codes where the people with two new confirmed cases of West Nile live unless mosquitoes in the area of the infected residents' homes also test positive for the virus.

The Nevada Department of Agriculture, Animal Disease Laboratory confirmed the existence of mosquitoes with West Nile in the following ZIP codes: 89107, 89122, 89128, 89130, 89014 (Arroyo Grande Sports Complex, Henderson), 89021 (Logandale), 89049 (Tonopah) and in a rural area near Moapa Warm Springs.

Citing medical privacy laws, the health district would only provide vague information about the new cases.

Health officials said two of the four confirmed cases are people over the age of 50 and two are under 50. All four residents developed severe symptoms of either meningitis or encephalitis or both. Two are currently in the hospital, and two were hospitalized but have been released.

Of the nine probable cases, six patients are over 50 and three are under 50, the health district said. Seven were severely ill. Three are currently hospitalized, and three were hospitalized and released. The other three sought short-term medical care at an emergency room or from a doctor.

No one in Clark County or elsewhere in Nevada so far has died from West Nile virus, the health district said. Nationwide this year 20 people have died from virus, including three in Arizona and seven in California, according to the federal Centers for Disease Control and Prevention. The agency reports 703 human cases of the virus have been confirmed in the United States this year.

In one recent California case, a 62-year-old Claremont man died of illnesses caused by the virus Thursday night, the San Bernardino County Coroner's Office reported. Walter Sheasby, a Green Party activist, died at Kaiser Permanente Hospital in Fontana after being hospitalized for 10 days with symptoms of West Nile. Test results at the hospital confirmed he had the virus.

Another Los Angeles man died Aug. 12 of the illness.

Humans are infected when they are bitten by mosquitoes carrying the virus. The mosquito season typically lasts until October, but it's impossible to predict how the virus may continue to spread in the region in the weeks ahead, David Tonelli, spokesman for the health district, said.

The virus is spread by birds carrying the virus, so it's not unusual that the virus jumped from the northwest end of the Las Vegas Valley to the southeast end and Henderson, Tonelli said.

But just because cases of West Nile virus have not been confirmed in other neighborhoods, doesn't mean the virus is not there, Tonelli said. Everyone in the valley should take precautions, using repellent with DEET, wearing long-sleeved shirts and long pants and avoiding the outdoors during dawn and dusk, when mosquitoes feed, he said.

"It's certainly prudent through at least October to take steps to personally protect yourself from mosquito bites," Tonelli said.

The health district and Clark County Vector Control are trying to control the mosquito population by trapping adult mosquitoes and killing larvae found in standing water, Richard Hicks, a supervisor for vector control, said.

The virus is carried by birds, but transmitted to humans by mosquitoes. About 20 percent of people bitten by an infected mosquito show flu-like symptoms, while about one in 100 suffer the most severe form of the illness.

Since standing water allows mosquitoes to breed, untreated pools continue to be a source of concern for Hicks.

"These (latest) cases are still from different areas of the valley," Hicks said. "In many of these cases the mosquitos are from backyard pools that aren't being maintained."

Officials are encouraging residents to make sure doors and windows have tight-fitting screens without holes and eliminate standing water, including bird baths, sprinkler run-off and murky swimming pools.

To report a stagnant swimming pool, residents can call Vector Control at the Clark County Public Works department, 455-7543.