Outbreak of Botulism Associated with

Fermented Beaver – Alaska, 2001

Louisa Castrodale, DVM, MPHSection of EpidemiologyAlaska Division of Public

Health

Outbreak

Southwestern Alaska village14 Alaska NativesBeaver paw and tailLunchtime on January 17Following morning, symptoms

compatible with botulism

Botulism

Ingestion of toxin produced by Clostridium botulinum

Blocks Ach release at neuromuscular junctions

Symmetrical descending paralysisIncubation 12-36 hrs (range 6-240)Case fatality rate 5-10%

Symptoms

GI, neurologic, respiratoryDiagnostic Pentad

Nausea or vomitingDysphagiaDiplopiaDilated, fixed pupilsDry throat

Botulism in Alaska

First outbreak in 1940sHighest rate in United StatesCase-patients all Alaska NativesConsuming traditional foodsRecent decline coincident with

prevention efforts by AIP-CDC

Methods

Interviews of exposed persons–Symptoms and onset–Food history

Details of food preparationSpecimens collected–Serum, stool, gastric aspirate–Beaver

Persons Exposed

Person Pentad Level Antitoxin # (n/5) of care (A/B & E)

1 4 tertiary* Y2 3 tertiary* Y3 3 tertiary Y4-14 < 1 observed N

each for >48 hrs

*placed on ventilator

Beaver Paws Tested for BotulinumToxin 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 ‘01Cut 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, BBAHCSusan Maslanka, CDC/Bot LabArctic Investigations ProgramAK State Public Health

Laboratory