June 14, 2005
COOK COUNTY MOSQUITOES POSITIVE FOR WEST NILE VIRUS
SPRINGFIELD, Ill. – Two mosquito samples collected in Cook County have tested positive for West Nile virus, Dr. Eric E. Whitaker, state public health director, today announced.
Both mosquito samples were collected June 6 in Evanston by the North Shore Mosquito Abatement District. The mosquitoes were tested by the Illinois Natural History Survey and the positive results were reported today to the Department.
Six 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 two mosquito samples from Cook County, a positive sample has been collected Johnson County and three positive samples have been reported in DuPage County. In addition, crows 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.
Only about two persons out of 10 who are bitten by an infected mosquito will experience any illness. Illness from West Nile disease 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
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