Public health officials in Colorado are warning the public to be aware of the dangers of foodborne botulism poisoning amid an investigation of several cases in the state.

Colorado Department of Public Health and Environment reports that the botulism patients have all had symptom onset since September. Testing from the Centers for Disease Control and Prevention confirmed four of the cases, one is still under investigation and test results are pending. All five cases occurred along the Front Range. The individuals are either hospitalized or recovering.

“Five cases of foodborne botulism in the span of a few months is unusual in Colorado and is cause for concern,” said Nicole Comstock, deputy branch chief of the state department’s communicable disease branch. “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.”

The department investigated the cases in September and October. Three of the patients appear to be unrelated because no common food item was identified. The other two confirmed cases were likely the result of an improperly canned shared food made in the same household, according to the health department’s public notice.

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. 

Prior to these recent botulism poisonings, the most recent confirmed cases of foodborne botulism in Colorado occurred in 2019 among a group that consumed a commercially prepared potato product held at improper temperatures.

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.

Additional steps people can take to reduce their chances of getting botulism include:

• 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, for example at 5,000 feet, boil for 15 minutes.

about botulism
While a variety of illnesses can result from eating under-processed food, one of the most dangerous is botulism poisoning. Untreated, botulism can paralyze the muscles needed for breathing, resulting in sudden death.

Anyone who has eaten any suspect — homemade or commercially prepared — food and developed signs of botulism poisoning should immediately seek medical attention, according to the U.S. Centers for Disease Control and Prevention (CDC).

“In foodborne botulism, symptoms generally begin 18 to 36 hours after eating contaminated food. However, symptoms can begin as soon as 6 hours after or up to 10 days later,” according to the CDC website.

The symptoms of botulism may include some of all of the following: double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, difficulty breathing, a thick-feeling tongue, dry mouth, and muscle weakness. People with botulism poisoning may not show all of these symptoms at once.

These symptoms result from muscle paralysis caused by the toxin. If untreated, the disease may progress, and symptoms may worsen to cause paralysis of specific muscles, including those used in breathing and those in the arms, legs, and the body from the neck to the pelvis area.