Safe Preserving: Largest botulism outbreak in 40 years

Image courtesy of Food Safety News.

Image courtesy of Food Safety News.

The Centers for Disease Control has issued a report on the largest botulism outbreak in the United States in 40 yearsOn April 19, 2015 a church in Lancaster, Ohio held a widely attended potluck luncheon at which potato salad containing home-canned potatoes was one item served. One woman died of respiratory failure linked to botulism poisoning two days after the event, and 29 other individuals were confirmed as having botulism associated with the outbreak.

Patients ranged in age from 9 to 87 years, with the majority (59%) female.   Illness began within 1 to 6 days after the potluck. Twenty-five (86%) patients received botulinum antitoxin, and 11 (38%) required endotracheal intubation and mechanical ventilation; no other patients died. Within 1 week of the first patient’s arrival at the emergency department, 16 patients (55%) had been discharged. Among 19 cases that were laboratory-confirmed, serum and stool specimens were positive for botulinum neurotoxin type A or Clostridium botulinum type A.

According to the investigation, the potato salad was prepared with potatoes home-canned using a boiling water canner. A boiling water canner does not generate sufficient heat to kill C. botulinum spores; a pressure canner must be used for home-canning of low-acid foods. In addition, the potatoes were not heated after removal from the can, a step that can inactivate botulinum toxin.

This was the largest botulism outbreak in the United States in nearly 40 years. In 1977, 58 cases of botulism were linked to home-canned peppers served in a Michigan restaurant. In the most recent case, early recognition of symptoms at the emergency room and a rapid, coordinated response likely saved lives, reduced illness severity, and allowed administration of the botulinal antitoxin in a reasonable time.

Botulism is a rare, but serious illness caused by the bacterium Clostridium botulinum. The bacterium is found in soil and can survive, grow, and produce toxin in a sealed jar of food. This toxin can paralyze nerves, eventually causing death. Even taking a small taste of food containing this toxin can be deadly.

Botulism is a medical emergency. A person with symptoms of foodborne botulism should seek medical care immediately. Symptoms may include the following:

  • Double vision
  • Blurred vision
  • Drooping eyelids
  • Slurred speech
  • Difficulty swallowing
  • Dry mouth
  • Muscle weakness

The Centers for Disease Control has a primer on botulism and home canning. Consumers are urged to remember to follow a research-tested recipe and to use proper equipment in working order when home canning. Safe preserving! Barb