By Tim Bonfield
The Cincinnati Enquirer

The first official signs this year of West Nile virus have arrived in Ohio.

State health officials said Thursday the virus had infected four birds found dead from four Ohio counties: a blue jay from Cuyahoga County, a crow from Medina County, a crow from Mahoning County and a grackle from Franklin County.

So far, no horse or human cases have been found, but the virus is active in Ohio and likely will spread to horses and humans before summer's end, said Dr. Nick Baird, director of the Ohio Department of Health.

"West Nile virus is a preventable disease spread to people by the bite of an infected mosquito. It is spread neither by birds nor direct person-to-person contact," Baird said. "I urge all Ohioans to take personal prevention measures ... and to eliminate mosquito breeding sites on their property."

Last year, Ohio endured the nation's third biggest outbreak of West Nile virus with 31 deaths and 441 probable and confirmed cases. Only Michigan and Illinois had more cases.

The bird findings mean that infected mosquitoes will be active all summer.

Even in areas where West Nile virus has been reported, fewer than 1 percent of mosquitoes carry the virus. Fewer than 1 percent of people bitten by an infected mosquito will become severely ill and most people will have mild symptoms or none at all, officials say.

In rare instances, however, West Nile virus can cause encephalitis (inflammation of the brain) or meningitis (inflammation of the covering of the brain and spinal cord).

People over the age of 50 and those with health problems are most susceptible to the serious complications related to the virus. Last year, experts also learned that the virus could spread through blood transfusions and organ transplants.

By July 1, possibly sooner, Hoxworth Blood Center expects to be testing all local blood donations for West Nile virus, said spokesman Michael Anderson.

Health officials recommend:

• When possible, avoid outdoor activities between dusk and dawn when mosquitoes are likely to be biting.

• If you must be outdoors when mosquitoes are active, cover up by wearing shoes, socks, long pants and long-sleeved shirts. Light colors are less attractive to mosquitoes.

• Use mosquito repellent that includes DEET.

• Eliminate mosquito breeding sites by removing discarded tires, tin cans, plastic containers, ceramic pots or similar water-holding containers; cleaning clogged gutters; keeping swimming pools chlorinated and draining water from pool covers; changing the water in bird baths at least once a week; and turning over plastic wading pools, wheelbarrows, and other items that collect water when not in use.

E-mail tbonfield@enquirer.com