West Nile virus reported in western U.S.

LARAMIE, Wyoming (CNN) -- State authorities are reporting what could be the first official cases of the West Nile virus in Colorado and Wyoming.

In Wyoming, a horse from eastern Goshen County near the Nebraska border died of encephalitis, said Terry Creekmore, West Nile virus project coordinator for the Wyoming Department of Health.

In Denver, the virus was detected in the blood of two horses and a dead crow from Weld County and one horse from Pueblo County, according to the Colorado Department of Public Health and Environment.

The Centers for Disease Control and Prevention has not officially confirmed the cases.

MORE STORIES • Time.com: West Nile: On the move  • Time.com: Person (ahem) of the Week  • A West Nile survivor's story  • Infectious diseases: A problem the world over    EXTRA INFORMATION • Interactive: Understanding West Nile virus  • Map: Outbreaks in the U.S.  • Map: West Nile activity in the U.S. from 2000 through 2002    CDC West Nile hot lines English 888-246-2675 Spanish 888-246-2875 Hearing-impaired 866-874-2646

"This is not a cause to panic," said Dr. Brent Sherard, Wyoming health officer. "We've been preparing for the arrival since last summer, and we're working at the state and local level to educate the public and providers to protect the health of our citizens."

Encephalitis and meningitis are rare, but potentially fatal, symptoms of the infection.

John Pape, an epidemiologist with the Colorado health department, called the detection the first among animals in his state. Two horses died, and a third is recovering.

No human cases were reported in either state.

On Saturday, federal officials confirmed two more deaths from virus, bringing the national toll to 11, eight of them in Louisiana. Nationwide, there are 251 confirmed or probable cases of the disease in people, the CDC said.

People in areas where the virus is present are urged to wear long-sleeve shirts and long pants and to use insect repellent containing the chemical DEET.

Before cool weather stops this year's epidemic, about 1,000 people could become sick with the disease, and about 100 of them are likely to die, a CDC official said last week.

West Nile virus was first reported in New York in 1999. Since then, the federal health agency has confirmed finding the virus in animals in 37 states and the District of Columbia.