Laboratory aspects of infant botulism in California.

Infant botulism is the newly recognized form of the disease in which illness results from the production of toxin in the infant's intestines. Between the recognition of infant botulism as a distinct clinical entity in 1976 and the end of 1978, 50 cases were identified in California. The diagnosis of botulism was established by the identification of botulinal toxin in and the isolation of Clostridium botulinum from stool specimens of the affected infants. Thirty cases were type A and 20 were type B. Fecal excretion of toxin and organisms was monitored during hospitalization and after discharge from the hospital. Stools from family members and from 160 age-matched control infants did not contain botulinal toxin. A total of 396 food and drug samples, as well as 159 environmental and miscellaneous items, were examined. None of the foods or drugs tested contained preformed toxin. However, C. botulinum organisms were isolated from the nine samples of honey, five of soil, and one of vacuum cleaner dust.