West Nile virus cases are beginning to creep into the Midwest and East, prompting health officials to caution the public about mosquitoes, even threatening sanctions against those who don't control standing water - the breeding ground for mosquitoes that spread the disease.

Last week an elderly man, whose name was not released, contracted the West Nile virus in Oconee County, South Carolina, according to the Greenville News. He had been fishing when mosquitoes bit him. The man had improved and was released from the hospital, according to the June 14 article.

The Centers for Disease Control says the virus, which first appeared in the United States in 1999, can infect people, horses, many types of birds, and some other animals.

Most people who become infected with West Nile virus will have no symptoms, or just mild ones, like headache and fever. West Nile virus infection sometimes, albeit rarely, triggers severe or fatal illnesses.

One out of 140 people bitten by an infected mosquito last year had symptoms. About half had mild symptoms while the other half had complications like encephalitis, meningitis, convulsions or paralysis. Those over age 50 are especially vulnerable.

Last year there were 4,156 human cases of the virus, including 284 deaths, according to the National Pesticide Information Center, a cooperative effort of the U.S. Environmental Protection Agency and Oregon State University.

There is no evidence to suggest that West Nile virus can be spread from person to person or from animal to person.

Last week in Lincoln-Lancaster County in Nebraska, a dead crow tested positive for the disease, the first case of the year in the state.

"We're taking it real seriously," Scott Holmes, manager of environmental public health for the Lincoln-Lancaster Health Department, told the Lincoln Journal Star in a June 14 article. "We want to know where people are seeing standing water."

Residents in that jurisdiction who don't take care of their standing water will be issuing abatement orders. If that doesn't work, residents will be fined up to $200 to charge government workers to clean up the breeding grounds.

And concerns are echoing throughout the country, particularly in the Midwest.

"We're seeing many more mosquitoes this year than in previous years, probably the past four or five," Robert Somrak, Stark County's director of environmental health, told Ohio's Canton Repository. "We've adopted the persona of the rainforest here in Canton, and the mosquitoes have taken full advantage by breeding."

Meanwhile, the EPA offers these tips for fighting mosquitoes, which will be out in full force in July, August, and September: