The Illinois Department of Public Health reported yesterday that the number of confirmed Salmonella Hvittingfos cases associated with Subway restaurants has climbed to 71.

Restaurant customers who have become ill with Salmonella infections range in age from 2 to 88 and reported eating at Subway restaurants located in 22 counties– Bureau, Cass, Champaign, Christian, Coles, Dewitt, Fulton, Knox, La Salle, Macon, Marshall, Moultrie, Ogle, Peoria, Sangamon, Schuyler, Shelby, Tazewell, Vermilion, Warren, Winnebago, and Will.

A specific food source has not yet been identified in association with the Subway Salmonella outbreak, although the Illinois Department of Public health is working closely with the U.S. Food and Drug Administration, the Centers for Disease Control and Prevention (CDC), the Subway restaurant chain and local health departments throughout the state to identify the source of illness.

According to the Illinois Department of Public Health, in a typical year only one to two cases of this type of Salmonella Hvittingfos are identified in the state.

According to the CDC, Salmonella is the leading cause of bacterial foodborne illnesses in the United States, and is responsible for approximately 1.4 million non-typhoidal illnesses in the US annually, including 400 deaths.

Typically, non-typhoidal Salmonella produces a self-limiting febrile gastrointestinal illness that is indistinguishable from that caused by other bacterial enteric pathogens. Dehydration is the principal clinical concern. The incubation period–the time between ingestion of Salmonella bacteria and the onset of illness–varies from six to 72 hours.

Numerous Salmonella outbreaks have been traced to the consumption of foods purchased from restaurants. The sources of such outbreaks include cross-contamination, contamination of food by ill food workers or service staff, and Salmonella-contaminated eggs, meat, and produce. Occasionally, investigators from public health departments and environmental health agencies are unable to determine how restaurant food came to be contaminated with Salmonella, and outbreak sources are unknown.

After the Salmonella outbreak was discovered, the Subway restaurant chain voluntarily withdrew all lettuce, green peppers, red onions, and tomatoes, from its restaurants and replaced the product with new, fresh produce.