Increase in foodborne botulism cases prompts warning from health officials about home food safety


Colorado Department of Public

Health and Environment

The Colorado Department of Public Health and Environment has investigated several cases of confirmed and suspected foodborne botulism in the state since September. 

Testing from the Centers for Disease Control and Prevention (CDC) confirmed four of the cases; one is still under investigation and two test results are pending. All of the confirmed cases occurred along the Front Range, and one of the unconfirmed cases occurred in the Western Slope. 

A majority of the cases appear to be unrelated as no common food item was identified. The last two confirmed cases were the result of an improperly canned shared food made in the same household. 

“Botulism does not spread from person to person, so there is no risk to the public. However, these cases are a good reminder of how important it is to properly preserve and handle food in the home,” said Nicole Comstock, deputy branch chief, communicable disease branch.

A variety of foods can be associated with foodborne botulism, including homemade foods that were improperly canned or preserved. The most common source of home-canning-related botulism cases come from foods with a low acid content, such as chiles, green beans, potatoes, beets, corn and asparagus.

To prevent botulism, it is important to follow proper canning and food preservation procedures. The Preserve Smart website from Colorado State University Extension provides information regarding considerations for choosing tested preservation methods and the importance of adjusting canning methods for elevation to ensure home-preserved food products are safe to enjoy. 

People can take the following steps to reduce their chances of getting botulism:

• Refrigerating homemade oils infused with garlic or herbs and throwing away any unused oils after four days.

• Keeping potatoes that have been baked while wrapped in aluminum foil hot (at temperatures above 140 degrees F) until they are served, or refrigerating them with the foil loosened.

• Refrigerating any canned or pickled foods after you open them.

• Before tasting or serving, boil all home-canned, low-acid vegetables for 10 minutes plus one minute for each 1,000 feet increase in elevation above sea level (e.g. at 5,000 feet, boil for 15 minutes).

Botulism is a rare but serious illness caused by a toxin produced by clostridium botulinum bacteria. When ingested, the toxin attacks the body’s nerves. Symptoms typically start with muscle weakness in the face and neck, and then spreads to the torso, arms and legs. The toxin weakens muscles used for breathing, which can lead to death. It is important that anyone ill with symptoms of botulism visit a health care provider immediately to be assessed. 

For more information about botulism, visit the CDC website at