In September 2022, McHenry County Department of Health (MCDH) staff investigated an outbreak of norovirus linked to D.C. Cobb's Restaurant located at 1204 N. Green Street in McHenry, Illinois. MCDH issued a press release asking patrons of the restaurant to complete a survey. Five hundred twenty people who either worked for or ate food at D.C. Cobb's were interviewed. A total of 173 people (168 patrons and 5 employees) were identified as outbreak cases. Dates of illness onset ranged from August 29, 2022 to September17, 2022. Two people were hospitalized. No one died. Five clinical specimens were positive for Norovirus G1.

Lettuce and green onion were statistically associated with illness. Multiple food safety violations were identified during facility inspections including inadequate temperature in food service hand sinks, improper hand washing procedures, and improper sanitation. At least 5 employees were confirmed through the employee survey to have worked at the restaurant during their infectious period after being symptomatic.