Infectious Disease
Norovirus Outbreak Associated with a Restaurant Exposure and Secondary Transmission at Atlantic Coast Conference (ACC) Field Hockey Louisville Kentucky 2025 Jordan Adams* Molly Parsch Parsch Parsch Parsch Parsch Parsch Parsch Parsch Parsch Parsch Louisville Metro Public Health & Wellness
Background: Norovirus is a leading cause of acute gastroenteritis in the United States and is highly transmissible through contaminated food, surfaces, and person-to-person contact. The virus causes an estimated $10.6 billion in annual U.S. economic losses.
Objective: To identify norovirus cases and characterize illness associated with restaurant exposure and secondary transmission among attendees of an Atlantic Coast Conference field hockey event.
Methods: We conducted a retrospective outbreak investigation using standardized case definitions to classify confirmed, probable, and secondary cases. Case identification occurred through chief complaints, interviews, and coordination with local and state health departments. Exposure histories were collected from individuals who dined at the restaurant between November 1–5 and from attendees of the field hockey event on November 4. Stool specimens from symptomatic individuals were tested for norovirus. Environmental health staff conducted on-site assessments of the restaurant, including evaluation of sanitation practices and employee illness reports.
Results: A total of 76 cases were identified. Illness onset occurred within six days of restaurant exposure. Common symptoms included vomiting (100%), diarrhea (92%), and fever (42%). Stool specimens tested positive for norovirus. Secondary cases became ill between November 4–6 after attending the field hockey event and were epidemiologically linked to restaurant-exposed cases. Ill food service employees were identified during environmental inspections. The primary mode of transmission at the restaurant remained undetermined.
Conclusion: Strengthening employee illness exclusion policies and enhancing regional specimen collection capacity may improve future norovirus outbreak detection and control.