Warm weather could bring back West Nile

COLUMBUS - This weekend's forecasts of balmy temperatures could bring a longing for summer's hot weather, thunderstorms and picnics.

But warm weather also brings birds - birds that could be carrying another round of the West Nile virus, a scourge that killed at least eight people in the state last year and infected more than 1,100 horses.

The West Nile virus causes encephalitis in humans, horses and several other animal species. The first U.S. case was confirmed in 1999. Locally, there were 12 confirmed human cases in the four counties served by the East Central District Health Department last year, but no deaths, according to Betty Plankinton, community risk reduction director

Plankinton said mosquitoes are key in the spread of the virus.

"It goes from birds to mosquitoes to either horses or humans. You can't get it from a horse," she said. "A mosquito biting a person won't transmit it to another person. It has to go through the bird. It has to have that intermediary host."

According to the Centers for Disease Control and Prevention, last year nearly 4,100 humans were infected nationally and 274 died. Nebraska, which ranked ninth out of 41 states in reported human cases, had 174 people test positive.

On April 1, Plankinton will be attending a state conference concerning the West Nile virus where health professionals will learn what to expect this year.

Health departments throughout the state will be trapping mosquitoes and collecting dead birds this year. Locally, the health department will continue to participate in surveillance efforts by collecting dead birds and sending them to the University of Nebraska for testing.

\ "They can deliver them here, or they can have the animal shelter pick them up and they will deliver them here," Plankinton said. "We're going to act as the shipping point for all four counties."

The East Central District Health Department serves Platte, Colfax, Boone and Nance counties.

The number of cases in the state's horse population exploded between August and October last year, going from no cases to more than 1,100, according to the state agriculture department's bureau of animal industry Web page.

The virus infects the central nervous system and causes symptoms of encephalitis. Infected horses may or may not show clinical signs, which include loss of appetite, depression, fever, quivering muscles, loss of muscle coordination, and weakness of limbs especially hind legs.

In humans, the symptoms of West Nile mimic the flu. The only way to know for sure whether the disease is present is by testing a person's blood.

"For most people, it's nothing, they wouldn't even realize they have it," Plankinton said. "For others, it's mild, flu-like symptoms: headaches, nausea and vomiting, high temperature."

A few people get severe headaches and a stiff neck with pain when they try to touch chin to chest.

"Those are the ones that are serious. Those are the ones that we have a problem with of the spinal cord and the tissues surrounding the brain," Plankinton said. "That's where the fatalities come from."

There is no treatment for the disease.

"We treat the symptoms," Plankinton said. "We can't do anything to treat the disease, we just treat the symptoms."

Once infected, neither people nor animals can transmit the virus. Transmission requires the intermediary of the mosquito, and even then, the mosquito has to first get the virus from an infected bird. The virus can't be transmitted by handling an infected dead bird.

After a person has been infected with West Nile, they are immune from getting it again.

Officials recommend reducing the risk of exposure by reducing the mosquito population through eliminating pools of standing water, the prime breeding habitat for the insects. Old tires should be removed, kiddie pools should be flipped over when not in use, and gutters should be cleaned out so leaves don't trap moisture, Plankinton said.

"The big thing is to get rid of standing water, so there's no standing water around your house," she said.

Reach Scott Aust at 563-7534 or scott.aust@lee.net.