West Nile Virus Spreads Faster

West Nile virus is spreading faster than it has in years, and the pace of the mosquito-borne disease is getting worse, health officials report. States are reporting more cases than usual, says Marc Fischer, a specialist in mosquito-borne diseases with the Centers for Disease Control and Prevention (CDC) in Fort Collins, Colo. "There's been a lot of mosquito activity in most states" this year, Fischer says.

Texas is getting the worst of it. Sixteen people have died of West Nile virus this summer in Texas. That's out of 381 cases of the illness. "We're on track to have the worst year ever," says Christine Mann, spokeswoman for the Department of State Health Services in Austin. 

Nationwide there have been at least 693 cases and 28 deaths, according to the CDC and state numbers released Tuesday. That's up from 390 cases and eight deaths last week.
A mild winter and ample spring rains allowed the mosquito population to build up early. Heat and scant rainfall are creating stagnant water pools, which make great breeding grounds, says Michael Merchant, an entomologist at the Texas AgriLife Extension Service in Dallas...