West Nile Virus (WNV) is spread to people by the bite of infected mosquitoes. Mosquitoes become infected when they feed on infected birds carrying the virus in its blood. Infected mosquitoes transmit the virus to people or other animals. WNV is not transmitted person-to-person or animal-to-animal. During blood feeding, the mosquito injects the virus, contained in its saliva into the bird, animal, or person - where the virus replicates and may cause illness. Only a small number of mosquitoes in an area carry the virus. Usually less than one out of a hundred carry the virus.

Most people who are infected will not develop symptoms. Some people may become ill 3-15 days after the bite of an infected mosquito. Evidence suggests that a minority of infected persons will develop a mild illness with fever, headache, body aches, and sometimes skin rash and swollen glands. There are no long-term effects due to mild illness.

WNV infrequently results in severe illness, known as West Nile Encephalitis. Encephalitis is an inflammation of the brain that may be marked by headaches, high fever, stiff neck, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. A small number of cases have been fatal.

The risk of West Nile Encephalitis is higher for persons 50 years of age or older. There is no documented evidence that a pregnancy is at risk due to a mother's infection with WNV.

No specific therapy is available for infection. In the case of West Nile Encephalitis, intensive supportive therapy may be required - such as hospitalization, intravenous fluids, respiratory support, prevention of secondary infections, and good nursing care.

Personal Prevention Measures:  Avoid outdoor activities between dusk and dawn when mosquitoes are likely to be biting. If you must be outdoors, cover up by wearing shoes, socks, long pants and long sleeves. Light colors are less attractive to mosquitoes. Use mosquito repellent containing DEET according to label directions. Adults should use repellant with no more than 30 percent DEET; for children, 10 percent or less.

Eliminate mosquito breeding sites. Mosquitoes lay their eggs in standing water. To avoid helping mosquitoes breed in your environment, drain standing water. Routinely empty water from flower pots, pet bowels, clogged drain gutters, swimming pool covers, discarded tires, buckets, barrels, cans and other items that collect water. Keep windows and doors closed and make sure screens are in good repair.

For more information, contact the Defiance County Health Department at 419-784-3818.