Botulism is a serious illness caused by an extremely powerful poison called botulinum toxin that paralyzes the muscles. The toxin is produced by a bacterium called Clostridium botulinum. Botulism develops if a person ingests the toxin or if the bacteria grow and release a toxin in a wound or in the intestines.

How many types of botulism are there? +

There are three main types of botulism, categorized by the way the disease is acquired. Food-borne botulism is caused by eating food contaminated with botulinum toxin. This typically occurs when a stored food item contains Clostridium botulinum spores which begin to grow and produce the toxin within the food item, if environmental conditions are favorable.

Wound botulism occurs when the Clostridium botulinum bacteria infects a wound and then produces the toxin.

Infant botulism occurs when an infant consumes the spores of the botulinum bacteria which are commonly found in the environment. Once the bacteria enter an infant's immature intestines, the spores can grow produce and release the toxins.

Adult intestinal botulism is the rarest form of botulism. Like infant botulism, it is caused when Clostridium botulinum spores are eaten in food. If environmental conditions are favorable in the intestinal tract, the bacteria may grow in that location and produce botulinum toxin, which is then absorbed into the bloodstream.


What are the symptoms of botulism? +

The classic symptoms of botulism include double and blurred vision, drooping eyelids, dry mouth, difficulty speaking and swallowing, difficulty breathing, poor reflexes, muscle weakness and paralysis. Infants with botulism appear lethargic and weak and are sometimes described as "floppy.' They feed poorly and have a weak cry and poor muscle tone. They can become constipated, which is often the first symptom. Symptoms of botulism are signs of muscle paralysis caused by the bacterial toxin. If untreated, the paralysis can affect various parts of the body, appearing as a descending paralysis first affecting the arms, then the legs, trunk and the breathing muscles. In severe cases, the patient may need to be placed on a breathing machine. The illness may last as long as a few months but is reversible. However, in severe cases that are not treated, it can be fatal.


How soon do symptoms appear? +

In food-borne botulism, symptoms generally begin 18-36 hours after eating a contaminated food. However, they can occur as soon as six hours or as late as 10 days afterward.


I am concerned that I have or someone who I know has botulism symptoms. What should I do? +

Anyone with botulism symptoms should contact a medical provider immediately. If walking, swallowing or breathing is affected, call 911. If you do not have a medical provider, call 911 to be directed to an emergency department.


Who gets botulism? +

Everyone is susceptible to foodborne botulism. Infant botulism is most frequently seen before six months of age, but all infants are susceptible. Persons who develop adult 'intestinal colonization' botulism usually have underlying medical conditions that have altered the normal intestinal environment, such as prior intestinal surgeries. Wound botulism can occur following injuries that involve dirty wounds (for example, motorcycle accidents) or if contaminated heroin is injected under the skin.


How is botulism spread? +

Foodborne botulism usually occurs after the ingestion of the toxin in foods which were not properly canned or preserved, and which were not adequately cooked or reheated before eating. Most cases in the United States are due to home-canned fruits and vegetables. Safe canning and manufacturing processes effectively control botulism in commercial food products. Infants can develop botulism by eating food contaminated with the bacterial spores, which then produce the toxin in the gastrointestinal tract. Although safe for children and adults, honey should not be fed to infants because it may contain Clostridium botulinum spores. However, most cases of infant or adult intestinal colonization botulism cannot be traced to a particular food item. Person to person spread of botulism does not occur.


How common is botulism? +

In the U.S., 110 cases of botulism on average are reported each year. Nearly 25% of cases are food-borne, approximately 72% are infant botulism and the remainder (about 3%) is wound botulism. In New York City, there typically is one to two infant botulism cases reported annually. The other types of botulism are much rarer. In 2011, there was a single, fatal case of the rare adult intestinal colonization botulism. It is not known how this patient was exposed. For the first time in more than 15 years, a confirmed case of foodborne botulism also occurred in 2011 when a New York City resident did not properly refrigerate his food. Two additional cases of foodborne botulism were diagnosed in 2012. These patients, who fully recovered, originated from the same region in China and both ate home-fermented tofu.


What is bioterrorism? +

Bioterrorism is the intentional use of biological agents, or germs, to cause illness. Bioterrorism has occurred in NYC only in 2001, when several media outlets received letters that were intentionally contaminated with anthrax bacteria. Botulism can be caused by bioterrorism.


How is botulism diagnosed? +

Botulism is typically diagnosed by finding the toxin in blood, stool, and the "suspected" food or in the skin of persons with wound botulism. Infant botulism and adult intestinal colonization botulism also can be diagnosed by growing the bacteria, Clostridium botulinum, from stool.


What is the treatment for botulism? +

If diagnosed early, food-borne and wound botulism can be treated with an antitoxin that blocks the botulinum toxin. The antitoxin can prevent the disorder from worsening, but recovery still takes many weeks. Antitoxin can only be given in a hospital. The respiratory failure and paralysis that occurs with severe botulism may require a patient to be on a breathing machine (ventilator) for weeks to months and may require intensive care. Depending on the severity of the illness, the paralysis can slowly improve over the course of weeks to months. Antitoxin is not used to treat infant botulism; however, the use of intravenous antibodies against the botulinum toxin may be effective.


What happens if botulism is not treated? +

Untreated botulism may result in death.


How can I prevent myself or others from getting botulism during this outbreak? +

If you have the food item that has been linked to this outbreak, follow Health Department recommendations.

Botulism cannot be spread from person to person.


How Will I Cope? +

A botulism outbreak in NYC can be very stressful, especially if it is large scale event. It can disrupt your everyday life and make you and those around you feel less safe. You may experience fear and uncertainty. Learning about stress and strategies to manage it can help you cope.

Prepare Today, Cope Better Tomorrow — Stress During Disasters (PDF) provides basic information and practical advice on dealing with the stress and anxiety caused by disasters. It is available in seven languages.

If there is a botulism outbreak in the city and you feel overwhelmed and unable to cope, or if you are concerned about someone else, you can find help by calling 988. 988 is a free, confidential helpline for New York City residents, available 24/7, with trained staff ready to take your calls and offer advice.


For more information about botulism, visit: Centers for Disease Control and Prevention (CDC)