Previously seen only in Africa, Asia and southern Europe, it first began appearing in North America in 1999 and spread throughout the northeast Arrived in Mahoning County in the summer of 2001.
Can cause encephalitis, a potentially fatal infection of the brain and spinal cord. Is spread to people by the bite of infected mosquito; the principal carrier is the northern house mosquito which becomes exposed when it feeds on birds that are infected.
The northern house mosquito breeds in standing water. It prefers to feed on birds rather than people.
In areas where mosquitoes carry the virus, less than 1 percent are infected. Less than 1 percent of people who get infected will become ill.
There is no evidence that the virus can be spread between humans or to humans from animals.
More than 80 percent of infections have been found in crows and blue jays.
As of July 18, there have been 152 human cases of West Nile virus illness, including 18 fatalities, reported and confirmed in the United States.
Dispose of unwanted cans, plastic containers and flower pots, and unwanted tires.
Change water in bird baths weekly and clean roof gutters twice a year. Turn over plastic wading pools when not in use.
Aerate Oriental pools or stock them with fish.
Wear long sleeves and long pants outdoors during the evening hours. Use an insect repellent containing DEET on skin and clothing. Do not apply repellent on children under 2.
Sources: Mahoning County District Board of Health, National Centers for Disease Control and Prevention