Early reports of West Nile 'distressing'

But no human cases seen yet this year

New York Times

SLIDELL, La. -- George Polk, an inspector for the St. Tammany Parish Mosquito Abatement District in this city, about 30 miles north of New Orleans, dips a long-handled ladle into a puddle beside a suburban lawn. He pulls out a cup of motionless black eggs and specks that wriggle like tadpoles -- mosquitoes.

In the laboratory, some may be found to be infected with the potentially lethal West Nile virus.

The virus first struck the Northern Hemisphere in New York City four years ago and killed four people. This year, all 50 states are warning of an outbreak.

No one is known to have caught it yet this year, but since January, the Centers for Disease Control and Prevention reported, the virus has shown up in 23 states.

"I would say that these early season reports of West Nile are distressing," said Michael Bunning, an epidemiologist at the National Center for Infectious Diseases in Fort Collins, Colo. "We haven't seen any sign that things are on a downward cycle."

No West Nile vaccine has been developed for humans.

Mosquitoes contract the virus from birds and pass it on through their saliva when they bite.

Louisiana began finding infected birds much earlier this year than last, meaning there might be human cases sooner than last year.