June 13, 2005
JOHNSON COUNTY MOSQUITOES POSITIVE FOR WEST NILE VIRUS
SPRINGFIELD, Ill. – Dr. Eric E. Whitaker, state public health director, today announced that a mosquito sample collected in Vienna in Johnson County has tested positive for West Nile virus.
The mosquito sample was collected June 3 by the Illinois Natural History Survey, which reported the positive test results to the Department today.
Four mosquito samples have been confirmed positive for West Nile virus since state and local health departments began surveillance for the mosquito-borne disease on May 1. No human cases have been reported.
Besides the mosquitoes from Johnson County, three positive samples have been reported in DuPage County. In addition, birds in Woodford and McLean counties have been confirmed positive for West Nile virus.
In 2004, 62 of the state’s 102 counties were found to have a West Nile positive bird, mosquito, horse or human case. A total of 60 human cases of West Nile disease, including four fatalities, were reported last year in Illinois.
Surveillance for West Nile virus includes laboratory tests on mosquitoes, dead crows and blue jays, and the testing of sick horses and humans with West Nile-like disease symptoms. Citizens who observe a sick or dying crow or blue jay should contact their local health department, which will determine if the bird is to be picked up for testing.
In 2002, the state led the nation with 884 human cases, including 66 deaths, and West Nile activity was reported in 100 of 102 counties. In 2003, 75 of the state’s 102 counties reported West Nile activity and there were 54 human cases of the mosquito-borne disease, including one fatality. Public health officials believe that a hot summer, like that of 2002, could increase mosquito activity and the risk of disease from West Nile virus.
West Nile virus is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Most people with the virus have no clinical symptoms of illness, but some may become ill three to 14 days after the bite of an infected mosquito. The first human case in Illinois is not usually reported until July or later.
Only about two persons out of 10 who are bitten by an infected mosquito will experience any illness. Illness from West Nile is usually mild and includes fever, headache and body aches, but serious illness, such as encephalitis and meningitis, and death are possible. Persons older than 50 years of age have the highest risk of severe disease.
The best way to prevent West Nile disease or any other mosquito-borne illness is to reduce the number of mosquitoes around your home and to take personal precautions to avoid mosquito bites. Precautions include:
Additional information about West Nile virus can be found on the Department’s Web site at www.idph.state.il.us/envhealth/wnv.htm or people can call the West Nile Virus Hotline at 866-369-9710 Monday through Friday from 8 a.m. to 5 p.m.
of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
Questions or Comments