Outbreak of Botulism Associated with Fermented Beaver Alaska

Outbreak of Botulism Associated with Fermented Beaver – Alaska, 2001 Louisa Castrodale, DVM, MPH Section of Epidemiology Alaska Division of Public Health

Outbreak Southwestern Alaska village 14 Alaska Natives Beaver paw and tail Lunchtime on January 17 Following morning, symptoms compatible with botulism

Botulism Ingestion of toxin produced by Clostridium botulinum Blocks Ach release at neuromuscular junctions Symmetrical descending paralysis Incubation 12 -36 hrs (range 6 -240) Case fatality rate 5 -10%

Symptoms GI, neurologic, respiratory Diagnostic Pentad Nausea or vomiting Dysphagia Diplopia Dilated, fixed pupils Dry throat

Botulism in Alaska First outbreak in 1940 s Highest rate in United States Case-patients all Alaska Natives Consuming traditional foods Recent decline coincident with prevention efforts by AIP-CDC

Methods Interviews of exposed persons – Symptoms and onset – Food history Details of food preparation Specimens collected – Serum, stool, gastric aspirate – Beaver

Persons Exposed Person # Pentad Level (n/5) of care 1 2 3 4 -14 4 3 3 <1 each Antitoxin (A/B & E) tertiary* tertiary observed for >48 hrs *placed on ventilator Y Y Y N

Beaver Paws Tested for Botulinum Toxin at CDC, Atlanta, GA

Results Toxin type E – Serum from Persons 1 and 2 – Stool from Person 3 – Beaver paws – Cultures pending

Fermentation Process Beavers hunted Nov ‘ 00 - Jan ‘ 01 Cut up and placed in heavy paper sack; left to ferment in entryway C. botulinum spores ubiquitous; toxin production facilitated by – Anerobic conditions – Warm environment

Summary Outbreak associated with consumption of fermented beaver Three cases of botulism confirmed

Recommendations Still a need to evaluate educational messages and prevention strategies that emphasize safe fermentation and consumption practices

Acknowledgments Coauthor: Michael Beller Andrea Horn, RS, BBAHC Susan Maslanka, CDC/Bot Lab Arctic Investigations Program AK State Public Health Laboratory