An international foodborne outbreak of shigellosis associated with a commercial airline.

OBJECTIVE: To determine the source of an international outbreak of shigellosis associated with consumption of food served by a Minnesota-based airline.

DESIGN: Cohort studies of players and staff of a Minnesota-based professional football team and passengers on flights with a confirmed case of outbreak-associated Shigella sonnei infection.

SETTING: Community- and industry-based studies conducted from October through November 1988.

PARTICIPANTS: Sixty-five football team players and staff, and 725 airline passengers in the cohort studies.

RESULTS: Twenty-one (32%) of 65 football players and staff developed shigellosis that was associated with consumption of cold sandwiches prepared at the airline flight kitchen (relative risk [RR], 17.1; 95% confidence interval [Cl], 2.4 to 120; P < .001). Confirmed or probable shigellosis was identified among 240 passengers on 219 flights to 24 states, the District of Columbia, and four countries between September 14 and October 13. An outbreak-associated strain of S sonnei was isolated from football players and staff, airline passengers, and flight attendants. Thirty (4.1%) of 725 passengers on 13 flights with confirmed cases had confirmed or probable shigellosis. Illness was associated with consumption of cold food items served on the flights and prepared by hand at the airline flight kitchen (RR, 5.7; 95% Cl, 1.4 to 23.5; P < .01).

CONCLUSIONS: This international outbreak of shigellosis was identified only because of the occurrence of an index outbreak involving a professional football team. Prevention of Shigella transmission in mass catering establishments may require reduction of hand contact in the preparation of cold food items or elimination of these items from menus.