Illinois reports eight human West Nile virus cases this year

Despite cooler temperatures, the Illinois Department of Public Health has recently warned that the threat of West Nile Virus is not over, reporting that there have been eight human cases of the disease this year.

Three cases each were reported in Cook and DuPage counties. Last year, there were a total of five human cases in the state.

“Although temperatures will start cooling down as we head into fall, the threat of West Nile virus is still alive,” Damon Arnold, health director of the IDPH, told Medical News Today. “We typically see the end of West Nile virus after the first couple hard frosts. Until then, people should continue to protect themselves against mosquitoes by wearing insect repellent.”

A 50 year-old-woman began showing symptoms of the disease in August was the first West Nile case of the year. The Tazwell County Health Department has since confirmed the case of human infection.

Overall, 27 counties in Illinois have reported mosquitoes, birds or humans testing positive for West Nile. The first two known identifications were in birds and reported on May 13. In 2009, the first cases were not found in animals until June 1, and 36 counties reported positive identifications overall.

West Nile Virus usually causes few signs or symptoms in humans, or generally just a headache or skin rash. A small percentage of the infected, however, can develop a life threatening illness, such as encephalitis and meningitis, as a result. The elderly and those with compromised immune systems are at greatest risk.

The virus belongs to the Flaviviridae family and is spread predominantly through mosquito bites. The Flaviviridae virus family also contains Japanese encephalitis, yellow fever and dengue fever.