Descriptive Epidemiology of Infant Botulism in California: The First 40 Years

Area of Science:

• Epidemiology
• Infectious Diseases
• Pediatrics

Background:

• Infant botulism is a paralytic illness caused by neurotoxigenic Clostridium species producing botulinum toxin (BoNT) in the infant gut.
• Initial recognition of infant botulism in California in 1976 prompted the need for comprehensive epidemiological surveillance.

Purpose of the Study:

• To determine the descriptive epidemiology of infant botulism over the first 40 years since its recognition in California (1976-2016).
• To identify and compare epidemiological characteristics between two 20-year periods (1976-1996 and 1997-2016).

Main Methods:

• Case definition based on laboratory identification of BoNT and/or neurotoxigenic Clostridium species in infant feces.
• Structured parental interviews to collect demographic and clinical data.
• Descriptive epidemiological analysis comparing two distinct 20-year time intervals.

Main Results:

• A total of 1345 cases were recorded from 1976-2016, with an incidence of 6.5 cases per 100,000 live births annually.
• The majority of cases (88%) occurred in infants ≤6 months old, with a slight female predominance (51%).
• Breast-fed infants were significantly older at onset (median 4.4 months) compared to formula-fed infants (median 1.7 months); BoNT/A cases were older than BoNT/B cases.

Conclusions:

• Forty years of surveillance in California revealed distinct epidemiological features of infant botulism, including high hospitalization rates (>99%) and a specific age distribution.
• The Central Coast region exhibited a disproportionately higher incidence of infant botulism.
• Key findings highlight the importance of continuous surveillance for understanding and managing this uncommon but serious pediatric condition.