[Epidemic outbreak in a home for the aged caused probably by Bacillus cereus].

OBJECTIVE

To identify the causative agent and the factors precipitating the outbreak.

METHODS

Observational, crossover study.

METHODS

Las Delicias Health district, Jerez de la Frontera.

METHODS

The population exposed, belonging to an elderly persons' home.

RESULTS

The total number of people exposed was the 425 persons living in an elderly persons' home in Jerez in November 1995. The clinical histories were reviewed, and a specific questionnaire used to interview 77 ill persons and 77 healthy ones. The criteria for ill cases were presence of vomiting and/or diarrhoea. 32.6% of the ill people had fundamentally vomiting; 24.67% diarrhoea, 37.66% vomiting plus diarrhoea, and 100% ran no temperature. Positive and significant OR were detected in various foods (from 2.36 to 10.52 OR). We isolated 3,000,000, and up to 5,600,000, colonies of Bacillus cereus per gram in several foods. We observed incorrect practices in the conservation and handling of foods.

CONCLUSIONS

Epidemiological, microbiological and clinical indications placed us before an outbreak of food poisoning probably caused by Bacillus cereus. The intervention at critical points, inter-institution coordination and communication in time and with data between professionals (microbiologist, doctors, nurses, vets and epidemiologist) were decisive in solving the outbreak.