Type A botulism from sauteed onions. Clinical and epidemiologic observations
K. L. MacDonald, R. F. Spengler, C. L. Hatheway, N. T. Hargrett and M. L. Cohen
Twenty-eight persons were hospitalized in Illinois with neurologic signs
and symptoms compatible with botulism in October 1983. Twelve patients
required ventilatory support, and 20 patients were treated with trivalent
ABE antitoxin; one patient died while still in the hospital six months
after onset of illness. Type A toxin and/or type A Clostridium botulinum
were subsequently identified in specimens from 18 patients. Case-control
studies implicated sauteed onions made from fresh raw onions and served on
a patty-melt sandwich in a local restaurant as the vehicle of transmission.
Although the original sauteed onions were not available for toxin testing,
type A toxin was detected in washings from a wrapper in which a patty-melt
sandwich was taken home by one of the ill persons. Also, type A C botulinum
was cultured from five of 75 raw onions taken from the restaurant. This
outbreak implicated an unusual vehicle for botulinal toxin that was
initially not suspected and demonstrates the importance of considering all
theoretically possible food items as potential vehicles for toxin until
epidemiologic and laboratory data have been collected and analyzed.
