Outbreak of aseptic meningitis--Whiteside County, Illinois, 1995.

Aseptic meningitis (AM) is a severe, nonbacterial infection of the central nervous system that affects an estimated 30,000-50,000 persons each year in the United States. On July 21, 1995, the infection-control coordinator of the county hospital in Whiteside County (1990 population: 60,000), Illinois, reported to CDC an outbreak of AM. From June 7 through July 21, 1995, a total of 29 persons had onset of clinical AM, characterized by fever, headache, stiff neck, and photophobia. Many cases had cerebrospinal fluid (CSF) pleocytosis, and all had negative bacterial cultures. Preliminary identification of an enterovirus was made from virus-isolation studies. This report describes the investigation of this outbreak by county and state health officials, which indicated that, although members of the community were concerned about possible transmission at large public gatherings and several swimming locations, there was no risk for illness in these settings.