Botulism mortality in the USA, 1975-2009

Botulism had mortality rates >60% before the 1950s. We reviewed confirmed botulism cases in the USA during 1975-2009 including infant, foodborne, wound, and other/unknown acquisition categories, and calculated mortality ratios. We created a multivariate logistic regression model for non-infant cases (foodborne, wound, and other/unknown). Overall mortality was 3.0% with 109 botulism-related deaths among 3,618 botulism cases [18 (<1%) deaths among 2,352 infant botulism cases, 61 (7.1%) deaths among 854 foodborne botulism cases, 18 (5.0%) deaths among 359 wound botulism cases, and 12 (22.6%) deaths among 53 other/unknown botulism cases]. Mortality among all cases increased with age; it was lowest among infants (0.8%) and highest among persons ≥80 years old (34.4%). Toxin type F had higher mortality (13.8%) than types A, B, or E (range, 1.4% to 4.1%). Efforts to reduce botulism mortality should target non-infant transmission categories and older adults.