An Outbreak of Food-borne Botulism Associated with Contaminated Locally-made Cheese in Iran

Cases of botulism in the northern province of Iran were studied in March and April 1997. A total of 27 patients were affected; 1 patient died. The samples were sent to the Department of Bacteriology, Pasteur Institute of Iran, for investigation. To identify the food source, several patients were interviewed and a case control investigation was conducted among families of hospitalized patients. Clinical and food specimens were tested. Toxin testing was positive for 37% of serum and stool specimens. Type A botulinal toxin was detected in cheese and Clostridium botulinum type A was isolated from cultures of clinical specimens and the cheese. This is the first documented outbreak of botulism due to Clostridium botulinum type A following consumption of cheese in Iran.