Botulism is a rare but serious foodborne illness most commonly caused by the bacteria Clostridium botulinum. Spores of this bacteria are naturally found dirt and dust, but are usually dormant. When given the right conditions, however, these spores can transform into an active bacteria and produce a deadly toxin. Eating foods infected with this nerve toxin can cause paralysis and death if not treated, but there are steps you can take to avoid consuming foods contaminated with botulinum.
Step 1: Understand How Botulinum Grows
Botulinum spores grow if given the optimal conditions -- which is a low or no-oxygen environment, some moisture, and typically a temperature range between 40 and 120 degrees Fahrenheit. In addition, low-acid foods, including most vegetables, figs, meat, chicken and fish, and foods that are low in sugar and salt are more likely to support the growth of botulinum.
Step 2: Understand and Avoid High Risk Foods
Because they are stored at room temperature and in a low-oxygen environment, home canned, preserved or fermented foods are the most common culprits in botulism outbreaks. Historically, other foods contaminated with this toxin include fermented fish, herb-infused oils, cheese sauce or foil-wrapped baked potatoes that have not been stored at the correct temperatures, bottled garlic and foods that have been kept warm and not exposed to air for extended periods of time. Also, honey is a source of botulinum spores and poses a risk to infants, as their immature digestive systems can allow toxin production and cause infant botulism. Because of this risk, infants under the age of 1 should not be fed honey.
Step 3: Inspect Canned or Jarred Foods
Because home canned, and rarely commercially-canned foods can be a source of the botulinum toxin, inspect canned or jarred foods for irregularities before opening. Do not purchase or open if the container is damaged or cracked, or if it is leaking, has bulges or is swollen. If you open a container and the food smells bad or is foamy, or if the food is moldy or discolored, don't consume it. Food tainted with this toxin may not smell or taste bad. So if you suspect the food is contaminated, don't taste it -- as even small amounts of the toxin can cause illness.
Step 4: When in Doubt, Safely Discard
If a friend, neighbor or relative gives you home-canned foods, be selective about what you choose to eat or feed your family. In order for these foods to be safe, proper equipment needs to be used and established procedures need to be followed. For example, the only way to process low-acid foods in temperatures high enough to kill botulinum spores is to use a pressure cooker or pressure canner, and to follow the recommended recipe, including heating and cooling times. In addition, home-canned foods should be stored between 50 to 70 degrees Fahrenheit, and most types of canned foods should be consumed within a year. If you are not confident the food was canned or stored properly, or if you don't know the source of the home-canned foods, the safest decision is to not consume it.
The Centers for Disease Control and Prevention (CDC) outline safe disposal of any foods suspected of botulinum contamination. Handle the container carefully using rubber or latex gloves, taking steps to avoid spills or splashes to the skin. Seal the food container in a sealable bag, then wrap another sealable bag around the first, and tape to secure. Place in non-recyclable trash, out of the way of other people or animals. Do not pour into the toilet or down the garbage disposal. Clean any spills with a solution of 1/4 cup bleach and 2 cups of water, and discard any sponges, washcloths or clothes that may have come in contact with the contaminated food. Wash hands for 2 minutes with soap and running water when done.
Infant botulism causes symptoms of poor feeding, poor muscle tone, a weak cry and low energy. Symptoms of foodborne botulism can begin as early as 6 hours after exposure, and usually include blurred or double vision, slurred speech, dry mouth and muscle weakness. These symptoms can progress to difficulty breathing, paralysis and respiratory failure. Death can occur if treatment is not initiated promptly, which includes an injection of antitoxin and ventilation to support breathing, if necessary. If you suspect you or a family member has consumed a food contaminated with the botulinum toxin, seed immediate medical attention.
Reviewed by Kay Peck, MPH RD