By: James Peacock

Clostridium botulinum, the bacteria that causes botulism poisoning, has been in the news frequently as of late. This rare form of foodborne illness is very dangerous, and when outbreaks do occur, they are almost always serious. Most recently, there was an outbreak of botulism poisoning that sickened 10 people in California. The outbreak was linked to nacho cheese sauce purchased from the Walnut Grove gas station near Sacramento, California. Only one bag was found to be contaminated with Clostridium botulinum. All ten people sickened in the outbreak were hospitalized, and one death was reported. Over the course of that outbreak investigation, testing revealed that the nacho cheese had the same strain of Clostridium botulinum that was found in the ill people. At least one person was paralyzed because of their illness but has since recovered.

Botulism in Europe

Botulism has also been in European news. There is currently an outbreak of Botulism poisoning in Ukraine. Over the last three months, there have been at least 62 confirmed cases of Botulism poisoning. Nine people have died because of their illnesses. Most of these illnesses have been connected to contaminated fish, both homemade and manufactured. Deputy Minister of Health of Ukraine Oksana Sivak held press conferences regarding the outbreak, and has said that the fish was of poor quality prior to being salted and distributed for consumer use. Illnesses have been reported in central and eastern Ukraine. Although the rate of infection is not too far above normal incidence rates, the supply of antitoxin in Ukraine has run out. International organizations are helping Ukrainian officials obtain the antitoxin for botulism toxin in an effort to prevent further harm.


The CDC has been tracking illnesses for quite some time. Each year, they gather data for foodborne illnesses in an effort to track and help prevent illness outbreaks. Usually, the finalized data depicts trends in illnesses from 2 years prior, as it can take time to compile and confirm reports of illness. The data for botulism poisoning cases was recently released. In the year 2015, Clostridium botulinum was responsible for 199 confirmed cases of botulism poisoning, as well as 14 probable cases. There are four different types of botulism poisoning, including infant, foodborne, wound, and unknown or other transmissions. These different categories of botulism infection may produce different symptoms, although they all have the same cause. There were 39 cases of foodborne botulism reported in 2015, making up about 20% of all cases. Six out of the 14 probable cases were also caused by foodborne botulism.

The 39 cases of foodborne botulism were spread out over seven different states, including: North Carolina, Ohio, Illinois, New Mexico, Utah, and Alaska. There were five outbreaks in 2015, which accounted for 37 out of the 39 reported cases of illness. The median age of patients was 59 years old. Three of the outbreak investigations uncovered the sources of the Clostridium botulinum contamination. One outbreak was caused by home-canned potatoes, one by fermented seal flipper, and one was caused by improperly handled beets. Out of the four possible types of botulism known to cause illness in humans (A, B, E, and F), only A and E caused illness in 2015. Toxin type A caused 34 cases of illness, and toxin type E caused five cases. The thirty-nine cases of foodborne botulism represent one of the most active years in recent memory, as the usual amount of foodborne botulism cases number in the teens. Botulism certainly appears to be on the rise, and outbreaks, like the latest one in California, have shown that the 2015 numbers may not be a fluke.

One of the biggest reasons for the increase in Botulism incidence in 2015 came from a single outbreak in the state of Ohio. A potluck dinner at a church in Lancaster, Ohio led to 25 confirmed cases and 4 probable cases. Twenty-seven of these patients had to go to the hospital because of these illnesses. Out of those sickened, 25 received antitoxin and 11 required incubation. The CDC sent 50 doses of antitoxin to Ohio. With so many people sickened, the CDC declared that this was the largest botulism outbreak in almost 40 years. The outbreak was caused by potato salad brought to the potluck. The potatoes used in the salad were home-canned. While a pressure canner would kill Clostridium botulinum spores, the potatoes were canned in a boiling water canner. This, added to the lack of heating potatoes after removing them from the can, failed to eliminate any botulism spores.

What is Botulism?

Botulism is a very rare form of foodborne illness. In fact, foodborne botulism is only one of four distinct ways to develop an infection. As noted above, these four kinds of botulism include wound, infant, foodborne botulism, and other transmissions. Even with five different types, botulism is fairly rare. In 2008, for instance, only 153 cases of botulism were reported to the CDC. Out of those cases, only 18 were considered to be foodborne in nature. Foodborne Botulism is transmitted by the bacteria known as Clostridium botulinum. These bacteria secrete botulinum toxin, of which only a few nanograms is required to cause illness. Most often, the cause for a foodborne botulism case is contaminated homemade canned foods. However, it is possible for Botulism to be caused by canned cheese sauce, chili peppers, tomatoes, carrot juice, and chopped garlic in oil. Foods that are not very acidic are at an increased risk of being contaminated with botulinum bacteria, so it is a good idea to keep these foods refrigerated. The CDC recommends following proper canning methods, keeping garlic or herbs in oil refrigerated, and keeping baked potatoes either hot or refrigerated as ways to help prevent the spread of Botulism. Boiling canned foods for 10 minutes prior to serving, regardless of if they are homemade or store bought.

The symptoms of Botulism poisoning will typically surface within an 18 to 36 hour window after infection, but there is the chance that symptoms show as early as 6 hours or as late as 10 days after infection. The symptoms of Botulism poisoning include: double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness. In infants, the following symptoms may appear: lethargy, loss of appetite, constipation, weak cry, and poor muscle tone. If the illness is left untreated, it can develop into causing paralysis in the arms, legs, and respiratory muscles. Diagnosis of a Botulism infection can take many forms, including: the usage of a brain scan, spinal fluid examination, tests for botulinum toxins, or a nerve conduction test. The reason for such a wide range of tests is because botulism presents in a similar way to other diseases, including Guillain-Barre, myasthenia gravis, and stroke. Botulism is treated with an antitoxin that is distributed by the CDC and through state health departments. The antitoxins can shorten the symptoms, as well as prevent the progression of the illness. Botulism is only deadly between 3 and 5 percent of the time, which is drastically reduced from the 50 percent mortality rate that was present just 50 years ago. Botulism poisoning still represents a significant risk though, as it can cause paralysis. Recovery from botulism poisoning can take weeks to months. Even after a recovery is made, someone who had botulism may have shortness of breath and fatigue for up to a few years after the illness. While all persons are at some risk for a botulism infection, users of IV drugs are at an increased risk of developing wound botulism. If you or a loved one begins to show the symptoms of botulism poisoning, contact a medical professional immediately.