West Nile virus hospitalizes woman, 75, in Southern Nevada

The first documented human case of West Nile virus in Clark County this year has left a 75-year-old woman hospitalized with a potentially fatal form of the disease, public health officials reported Friday.

That notification comes two weeks after the Southern Nevada Health District found West Nile virus-infected mosquitoes circulating in the Las Vegas Valley and three days after the federal Centers for Disease Control and Prevention announced that the 2,636 cases reported nationwide in 2012 through September – a figure that includes 118 deaths – is the highest number of cases reported over that time frame since 2003.

Health officials citing federal privacy laws would not disclose the identity the Southern Nevada woman suffering from the virus or where she was hospitalized. But they did say she suffers from the serious neuroinvasive form of the virus that affects nervous systems and can cause encephalitis, an inflammation of the brain, and meningitis, which causes inflammation to the membrane around the brain and spinal cord.

Devin Barrett, a senior disease investigator the health district, warned residents Friday that the standing water left by heavy rains that hit Las Vegas early this week can be a dangerous breeding ground for more mosquitoes.

Mosquitoes pick up the virus from infected birds and transmit it to humans, birds and other animals they bite.

"If you see water in pots, wheelbarrows, tires or whatever, turn it over, take measures to eliminate it," she said.

She said residents who see standing water near washes or creeks or on public lands should call health district vector control at 759-1220. Reports of dirty, "green" swimming pools should be made to city of Las Vegas enforcement authorities at 229-6615 and to Clark County officials at 455-4191.

Barrett also recommended that people apply an insect repellent containing DEET, particularly during the evening and early morning when mosquitoes are most prevalent.

"We initially found the mosquitoes with the virus in the 89107 zip code, but we’re now confident they’re throughout the entire valley," Barrett said. "We have about two more months in which we have to be vigilant about the virus."

Last year, Nevada reported 16 cases of West Nile, 11 of them in Clark County. One person died from the disease.

Since 2004, the first year the disease appeared in Clark County, five people have died from the disease in Nevada.

According to the CDC, the severe form of the virus is seen in one in 150 cases, with symptoms ranging from high fever and headache to coma and paralysis. The symptoms may last several weeks, and neurological effects may be permanent.

There is no specific treatment for the virus, which has sickened more than 30,000 people and killed more than 1,200 since it first appeared in the United States in 1999. Victims are hospitalized and given supportive treatment, including intravenous fluids, help with breathing and nursing care.

In rare cases, the disease has been spread among humans through breast-feeding, organ transplants and blood transfusions. It is not spread through casual contact such as touching or kissing someone with the virus.

Eighty percent of the people who contract the virus never have symptoms. The less dangerous form of the disease can produce symptoms that are similar to the common cold.

Barrett said she is concerned by comments she hears from many new Nevadans who think this area is too hot and dry to have mosquitoes.

"We don’t have as many, but there’s no doubt we have them, and it pays to be vigilant," she said.

Contact reporter Paul Harasim at pharasim@reviewjournal.com or 702-387-2908.