Most people who are infected with the virus won't get sick. About a fifth of those infected will develop a fever, headache, body aches and sometimes a rash and swollen lymph glands. Symptoms can last for as short as a few days, though even healthy people have been sick for several weeks.

To prevent the area underneath from becoming a mosquito nursery and an incubator for West Nile virus, keep the stuff -- garden equipment, tools, toys -- under your deck clear of rainwater, said David Gaines, an entomologist for the Virginia Department of Health.

With items hidden from view, it's "out of sight, out of mind," he said.

"It's amazing how many people breed mosquitoes under their decks," said Gaines, who admits to sometimes forgetting to dump rainwater out of his own garden containers and pots.

He suggests that homeowners routinely check under their deck and around their yards and homes to ensure that they're not inadvertently encouraging the spread of the mosquito-borne disease. That means clearing the water out of wheelbarrows, birdbaths, plant saucers and boats.

88 West Nile Deaths Nationwide

West Nile virus spreads to birds, humans, horses and other mammals from the bite of infected mosquitoes. The sometimes fatal virus was first detected in Virginia in the fall of 2000, a year after it was first detected in North America.

Last year, there were 2,470 cases and 88 deaths nationwide. State figures show five human cases of West Nile infection, including one death, in 2004. In 2003 there were 26, with one death, in Virginia.

State public health officials are already on the lookout for West Nile's return this year. So far, 19 birds and 309 mosquito colonies or "pools" have been tested, with no West Nile infections as of Friday, according to Denise Pettit of the state's Division of Consolidated Laboratory Services.

Gaines noted that testing involved about 12,000 individual mosquitoes. No human cases have been reported.

"It's been an unusually cool spring," he said, adding that lower temperatures prevent the virus from replicating.

Most Won't Get Sick

Summer temperatures and typically drier weather will mean infected mosquitoes, followed by infected birds and other animals, such as horses. Most human cases in Virginia come in late summer, when the virus has had time to build up strength.

Most people who are infected with the virus won't get sick. About a fifth of those infected will develop a fever, headache, body aches and sometimes a rash and swollen lymph glands. Symptoms can last for as short as a few days, though even healthy people have been sick for several weeks.

About one in 150 people infected develop West Nile encephalitis or meningitis, which has symptoms that include headache, high fever, neck stiffness, disorientation and sometimes paralysis.

People typically develop symptoms between three and 14 days after they are bitten by an infected mosquito. Those older than 50 are more likely to develop serious symptoms and should take special care to avoid mosquito bites.

There is no vaccine or specific treatment for humans, although several potential therapies and vaccines are being studied.

Controlling Mosquitoes

Eliminate mosquito-breeding areas:

Protect against biting mosquitoes: