Clostridium botulinum food poisoning
Botulism is an infectious disease caused by the bacterium Clostridium botulinum. Although rare, botulism is a serious paralytic illness caused by a nerve toxin, which is produced by the bacterium. This potent toxin blocks nerve function, leading to respiratory and musculoskeletal paralysis. The illness is most typically characterized by double vision, inability to swallow, difficulty speaking, and inability to breathe. Botulism can be fatal. If you think that you may have been infected by the bacterium, you should seek immediate medical attention!
Approximately 110 cases of botulism food poisoning are reported to the U.S. Centers for Disease Control and Prevention (CDC) each year. Of these, about 25% are foodborne, 72% are infant botulism, and 3% are wound botulism.
What are the symptoms of foodborne botulism?
Botulism food poisoning can be fatal, and should be treated as a medical emergency. Symptoms may include dry mouth, difficulty swallowing, slurred speech, muscle weakness, blurred vision, double vision, and drooping eyelids. If left untreated, muscle paralysis may progress to the arms, legs, trunk, and respiratory muscles, possibly resulting in death. Symptoms usually appear 12 to 36 hours after consuming C. botulinum toxin; however, symptoms can occur as early as 6 hours, or as late as 10 days, following the consumption of contaminated food.
There are three main kinds of botulism:
- Foodborne botulism is a rare form of foodborne illness, caused by consuming food contaminated with botulism toxin.
- Wound botulism is also caused by botulism toxin, produced from a wound infected with C. botulinum.
- Infant botulism occurs when infants ingest C. botulinim spores (often found in honey). The spores may then germinate and produce toxin in the gastrointestinal tract.
How is botulism caused?
Foodborne botulism is caused by ingesting food contaminated with a powerful nerve toxin, produced by the bacterium C. botulinum. Botulism is most often associated with eating improperly canned foods and smoked or salted fish. It poses a serious health problem since many people can become poisoned from a single contaminated food source.
How is botulism diagnosed and treated?
According to the CDC, your physician may consider a diagnosis of botulism based on patient history and physical examination. However, in order to distinguish botulism from other diseases with similar symptoms, your doctor may also order medical testing, which may include a brain scan, examination of spinal fluid, a nerve conduction test and a tensilon test (for myasthenia gravis). The most direct way to diagnose botulism is to demonstrate C. botulinum toxin in the patient’s serum or stool. This is accomplished by injecting the patient’s serum or stool into mice, and looking for signs of botulism. Clostridium botulinum bacteria can also be isolated from the stool of persons with foodborne botulism.
The CDC also reports that patients suffering from respiratory failure and paralysis may be placed on a breathing machine (a ventilator) for weeks, in addition to requiring intensive medical and nursing care. Paralysis will slowly improve after several weeks. If diagnosed early, patients with botulism food poisoning can be treated with antitoxin, which acts by blocking the action of the toxin circulating in the blood. While this may prevent progression of the illness, recovery may still take many weeks. Physicians may also try to remove contaminated food from the gut by inducing vomiting or by using enemas.
Are there any complications associated with botulism?
Clostridium botulinum toxin is extremely potent. Without proper treatment, botulism can result in death due to respiratory failure. A patient with severe botulism poisoning may require use of a breathing machine and intensive medical care for several months. Patients may experience fatigue and shortness of breath for several years following their recovery from botulism poisoning.
How can botulism be prevented?
The following precautions can help prevent botulism poisoning:
- While home canning, follow strict hygienic practices to reduce contamination of foods.
- The botulism toxin is destroyed by high temperatures. Persons eating home canned foods should boil the food for ten minutes before consuming it.
- Canned foods contaminated with C. botulinum and its toxin may show signs of outward can bulges as a result of a build-up of gas produced by the bacteria. Canned foods showing outward can bulges should be thrown away and not consumed.
- Refrigerate oils containing garlic or herbs.
- Potatoes cooked in aluminum foil should be served hot or be refrigerated.
- Wound botulism can be prevented by promptly seeking medical attention for infected wounds and by not using injectable street drugs.
- To help prevent infant botulism, children under 12 months of age should not be fed honey or other sweeteners, which may contain C. botulinum.