Investigating on a foodborne outbreak: analysis of the critical points

The Authors describe an epidemiological survey performed after a cluster of cases of foodborne infection involving several participants at a wedding reception. The aim was to identify the food, the responsible pathogen and any shortcomings in the coordination between the various services and the territorial operating units involved in the outbreak investigation. The investigation involved 149 participants; fifty seven persons (38.3%) had a foodborne illness. The only food item that remained associated with illness after multiple regression analysis was the ricotta cheese (RR 3.58, I.C. 1.,72-7.48 ). The finding of B. cereus in samples of ricotta cheese collected at the dairy food supplier indicate its responsibility for the outbreak but diagnostic certainty could not be achieved as no leftovers were available. Thus, shortcomings in this epidemiological investigation are constituted by: delayed notification, which prevented the acquisition of food samples, lack of a reference laboratory and lack of a specific diagnostic protocols, which prevented the microbiological research for the rapid identification of new pathogens incriminated in foodborne diseases. Finally, environmental and sanitary inspections showed deficiencies in the hygienic measures of food storage, particularly regarding refrigeration and in the HACCP plan that was not properly implemented.