Tests confirmed that a 45-year-old Grand Island man has contracted the disease. Currently under treatment in Niagara Falls Memorial Medical Center, he became ill Aug. 30, suffering from fever, muscle pain, headache, stiff neck and an altered mental status.

Earlier this week, a 70-year-old Cheektowaga woman was identified as the county's first West Nile virus patient. She has returned home after hospital treatment.

Including this case, there have been 29 human cases of West Nile virus in New York State this year. Six more were reported in the New York City area Thursday.

The disease is spread by infected mosquitoes and was first detected in dead crows. It reached Erie County two years ago, but no human cases had been reported here until this week.

Nationwide, 1,295 people have tested positive for the disease, and 54 have died.

West Nile symptoms are often similar to those of the flu. But in rare cases, the virus can cause encephalitis, a swelling of the brain that can be fatal.

Billittier noted that "a very small percentage, less than 1 percent, of mosquitoes actually carry the virus. If bitten by an infected mosquito, less than 1 percent of people will become seriously ill. Approximately 80 percent of people with West Nile virus have no symptoms at all."

Billittier said people over 50 have the highest risk of developing serious illness from the virus. He advised county residents to try to avoid mosquito bites by covering exposed skin and using insect repellent.

The commissioner again urged residents to reduce breeding sites for mosquitoes by draining standing water. He also asked that dead crows be reported to the New York State West Nile Virus Hotline by calling toll-free (866) 537-2473 (dial 1 first).