Home-canned Potatoes Likely Source of Botulism in Ohio

It is not a common disease, but botulism has made headlines recently due to a deadly outbreak in Lancaster, Ohio. Over 20 people were sickened and one woman died after eating food at a church potluck. One week after the potluck, over half of those who became ill remained hospitalized.

Foodborne botulism is often associated with food that has been improperly handled during the canning process. It is caused by a toxin that is produced by the bacterium Clostridium botulinum. This rare but serious disease leads to muscle paralysis and signs and symptoms such as muscle weakness, drooping eyelids, blurred vision, double vision, slurred speech, dry mouth and difficulty swallowing. If left untreated, the disease can progress to cause paralysis of the muscles used for breathing as well as muscles of the trunk, arms and legs.

All of the people who were sickened in Ohio showed the typical signs of the illness within the usual time frame of 18 to 36 hours after eating and were taken to hospitals for treatment. The Centers for Disease Control and Prevention (CDC) sent a large amount of antitoxin overnight, and those affected were given the treatment. If given early, antitoxin can prevent the illness from progressing and shorten the time for recovery.

Meanwhile, public health officials worked to determine the food that was the source of the illness. Though the signs and symptoms and timing of their appearance were typical and officials were fairly certain it was botulism, testing was conducted to confirm that was the case.

In these situations, testing is carried out by some state health departments or the CDC and involves detecting the botulinum toxin and/or identifying C. botulinum. Samples from patients as well as from suspected food sources are typically tested for confirmation. In the Ohio cases, testing confirmed that home-canned potatoes that were used to make a potato salad were the likely source of the illnesses.

Though rare, outbreaks of foodborne botulism in the U.S. have occurred in the past. There were 116 outbreaks reported to the CDC between 1996 and 2008. Home-prepared foods caused 48 of those outbreaks and, in particular, home-canned vegetables caused 18 of those (38%). Because so many outbreaks of foodborne botulism are caused by food processed or canned at home, authorities in Ohio looked in particular at anything from the potluck that was made with home-canned food as a possible source of this latest outbreak.

Food that is tainted with botulinum bacteria and toxin usually does not look, smell or taste different. This makes it difficult to know when food is contaminated and the CDC cautions against tasting anything that is suspect. But the chances of getting sick can be decreased by inspecting canned food when it is opened and discarding it if it is discolored, smells or appears moldy, for example. Canned foods that spurt liquid or foam when opened should not be used. Throw away food in containers that are leaking, damaged, cracked, bulging or swollen. The botulinum toxin is destroyed by heat, so it is recommended to boil home-canned food for 10 minutes before eating.

To learn more about how to avoid getting this foodborne illness, see the CDC webpage About Botulism. One of the most important ways to prevent foodborne botulism is to follow proper home-canning techniques. For details, download the U.S. Department of Agriculture's Complete Guide to Home Canning.