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Botulism and Commercial Pot Pie -- California

On August 3, 1982, a 56-year-old woman residing in Los Angeles County, California, developed diplopia, weakness, difficulty breathing, and chest pain. She had respiratory arrest on admission to the hospital but was intubated, resuscitated, and placed in intensive care. Examination showed complete bilateral ptosis, ophthalmoplegia, facial muscle weakness, and areflexia. Cerebrospinal fluid was normal except for increased glucose; Tensilon test was negative. She had a past history of seizure disorder, diabetes mellitus, and organic brain syndrome. An infectious disease consultant thought her subsequent fever was due to pneumonia secondary to aspiation, and he suspected botulism as the underlying cause of her illness.

The patient lives with her husband and grown son who both prepare meals for her and attempt a strict diet in consideration of her diabetes. When asked about the patient's food history before onset of illness, the husband and son named no likely suspects for botulism. No home-preserved foods had been served, and, with one exception, she had not eaten other foods that were not freshly prepared for her or were not also consumed by her husband and son. The exception was commercial beef pot pie, which was accidently mishandled, then consumed by the patient 1 day before illness began.

The son had prepared the pot pie for an earlier evening meal. The frozen pie was baked in an oven for 40-45 minutes. As he was about to serve it to his mother, his father came home with some freshly cooked hamburgers just purchased at a take-out restaurant. The pot pie was put aside on an unrefrigerated shelf. Two and one-half days later, the son came home and found his mother had just consumed this pot pie without reheating it.

An uneaten portion of the pot pie, still in its metal plate, was retrieved by the family members. Type A botulism toxin was found in this pie by a mouse-inoculation test performed at a U.S. Department of Agriculture laboratory in Beltsville, Maryland, and type A toxin was also demonstrated in the patient's serum by the state's Microbial Disease Laboratory.

Editorial Note

Editorial Note: This is the third case of botulism associated with commercial pot pies reported from California (1,2); one other episode (involving two clinically diagnosed patients) was reported from Minnesota in 1960 (3). Mishandling of the pot pies occurred in three of these episodes, and mishandling was also suspected in the fourth. The known mishandlings consisted of leaving the baked pot pie in the oven with the pilot light on, thereby maintaining "incubator" temperatures overnight. The pies were then eaten with no (or insufficient) reheating to destroy toxin. Or, as in the present case, the baked pie sat out at room temperature for over 2 days during hot weather--conditions that also could simulate an incubator.

In these situations, it is suspected that the original baking killed competing organisms in the pies and eliminated much of the oxygen. The heat-resistant, anaerobic Clostridium botulinum, which was evidently present and can be found in many fresh, frozen, and other food products, was then presumably able to germinate and produce toxin under the crust during storage at warm, incubator-like temperatures. Products such as pot pies should be kept frozen before heating and ideally should be served hot after the first cooking. If any such products are to be saved, it should be quickly refrigerated, then reheated to hot temperatures. This would minimize any risk of botulinal poisoning. Reported in California Morbidity, November 12, 1982;(44).


  1. State of California, Department of Health Services. Botulism--home-canned figs and chicken pot pie. California Morbidity 1975, No. 46.

  2. State of California, Department of Health Services. Type A botulism associated with commercial pot pie. California Morbidity 1976, No. 51.

  3. CDC. Botulism. MMWR 1960;9(27):2.

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