Clinical Features of Types A and B Food-borne Botulism

Medical records of 55 patients with type A and type B food-borne botulism reported to the Centers for Disease Control during 2 years were reviewed to assess the clinical features and severity of illness, diagnostic test results, nature of complications, and causes of death. Some patients had features not usually associated with botulism including paresthesia (14%), asymmetric extremity weakness (17%), asymmetric ptosis (8%), slightly elevated cerebrospinal fluid protein values (14%), and positive responses to edrophonium chloride (26%). Several observations suggest that type A was more severe than type B disease. Although the case-fatality ratio was not significantly greater, patients with type A disease saw a physician earlier in the course of illness, were more likely to need ventilatory support, and were hospitalized longer. Patients who died were older than those who survived. Deaths within the first 2 weeks resulted from failure to recognize the severity of the disease or from pulmonary or systemic infection whereas the three late deaths were related to respirator malfunction. BOTULISM caused by food contaminated with a neurotoxin of Clostridium botulinum is an uncommon disease in the United States. Types A and B botulinal toxin accounted for 87% of outbreaks and 91% of cases of known toxin type reported to the Centers for Disease Control (CDC) from 1970 through 1979 (1-3). Because the disease is rare, most clinicians have never seen a case. Textbook descriptions have frequently been based on clinical data from individual botulism outbreaks