International outbreak of severe botulism with prolonged toxemia caused by commercial carrot juice.

Background: On 8 September 2006, 3 Georgia residents presented with symptoms of food-borne botulism, a potentially fatal illness caused by Clostridium botulinum neurotoxins.

Methods: Investigators reviewed medical records and interviewed patients and family members. Foods from patients' homes and samples of the implicated commercial beverage were tested for botulinum toxin and C. botulinum by standard methods.

Results: The patients presented with cranial neuropathies and flaccid paralysis; all patients required mechanical ventilation. The 3 Georgia patients had consumed carrot juice from the same bottle before illness onset. An additional case in Florida and 2 in Ontario, Canada, were subsequently identified in patients who had consumed carrot juice. Serum samples obtained from 5 patients tested positive for botulinum toxin type A-in one patient, 12 days after illness onset, and in another patient, 25 days after illness onset. Carrot juice produced by 1 manufacturer, recovered from patients' homes in Georgia, Florida, and Ontario, yielded type A toxin. The juice contained no added sugar, salt, or preservative; inappropriate refrigeration likely resulted in botulinum toxin production.

Conclusion: This outbreak was caused by commercially produced, internationally distributed carrot juice that was contaminated with botulinum toxin. When toxemia persists, treatment for botulism should be considered even if diagnosed weeks after illness onset. The implicated pasteurized carrot juice had no barriers to growth of C. botulinum other than refrigeration; additional protective measures for carrot juice are needed to prevent future outbreaks. The US Food and Drug Administration has since issued industry guidance to reduce the risk of C. botulinum intoxication from low-acid refrigerated juices.