Infant botulism: clinical spectrum and epidemiology.

Between 1977 and 1979, 12 cases of infant botulism were diagnosed in Utah, and 87 control patients (normal, nonbotulism neurologic disease, and nonbotulism systemic disease) were evaluated. Observations from these patients suggest an expanded clinical spectrum of infant botulism including asymptomatic carriers of organism; mild hypotonia and failure to thrive; typical cases with constipation, bulbar weakness, and hypotonia; and children with a picture compatible with sudden infant death syndrome. Clostridium botulinum was isolated from the stools of three normal control infants and nine control infants who had neurologic diseases that were clearly not infant botulism. These infants were termed "asymptomatic carriers" of the organism. The occurrence of the asymptomatic carrier state suggests that a diagnosis of infant botulism cannot be made on a basis of culture results alone, but must rest in historical documentation and physical confirmation of progressive bulbar and extremity weakness with ultimate complete resolution of symptoms and findings over a period of several months. A common set of environmental features characterizes the home environment of children with infant botulism and "asymptomatic carriers" and includes: nearby constructional or agricultural soil disruption, dusty and windy conditions, a high water table, and alkaline soil conditions.