Fleck-Derderian S, et al. - A systematic review of foodborne botulism outbreaks was performed to delineate their clinical aspects and descriptive epidemiology in order to inform public health response strategies. As per findings, half of the outbreaks were related to Toxin type A and in addition, these outbreaks had a higher proportion of patient ventilatory failure. Due to point source exposures, most outbreaks occurred, while outbreaks due to commercial food were larger. The need for timely outbreak investigation and hospital surge capacity had been recommended for effective responses to foodborne botulism outbreaks.

Methods

• Seven databases were searched for reports of foodborne botulism outbreaks published in English from database inception to May 2015.
• Descriptive characteristics were summarized and differences in exposure and toxin types by geographic region were analyzed.
• Correlations between exposure source, implicated food, and outbreak size were assessed by performing logistic regression.

Results

• Reports of 197 outbreaks from 1920 to 2014 were identified.
• In this study, the median number of cases per outbreak was 3 (range 2–97).
• In the United States, the majority of reported outbreaks (109; 55%) occurred.
• The causative agent identified were toxin types A, B, E, and F in 34%, 16%, 17%, and 1% of outbreaks, respectively.
• Between exposure and symptom onset, the median duration was around 1 day.
• Per outbreak, the mean percentage of cases requiring mechanical ventilation was 34%. 
• From point source exposures, 70 % of all outbreaks and 77% of small outbreaks (≤11 cases) originated, however, commercial foods were markedly (odds ratio, 6.9; 95% confidence interval, 2.2–21.1) associated with large outbreaks (≥12 cases).