Getting a handle on West Nile virus.

• Position: YOUR LIFE

"We expect to see steady to declining numbers of clinical West Nile virus cases this summer," states Gayle Johnson, associate professor of veterinary pathobiology at the College of Veterinary Medicine, University of Missouri, Columbia. "Reported cases in horses have significantly decreased. The horses have developed a strong immunity to the disease that can be attributed to vaccination or subclinical infection. The human population can still be exposed to the virus, however, because infected birds, especially crows and blue jays, can still be found in the environment."

West Nile virus first was detected in the Western Hemisphere in New York in 1999. According to the Centers for Disease Control, Atlanta, Ga., four out of five people infected by West Nile will not develop any symptoms, which may include fever, headache, body aches, and disorientation. The elderly are the most likely to be affected. People and animals who live in areas with a large mosquito and bird population also have a higher risk of contracting the disease.

"There are a number of steps people can take to protect themselves and their animals, including wearing...