Botulism

Botulism (BOCH-u-liz-em) is food poisoning caused by eating food containing Clostridium botulinum bacteria or the toxin they produce. Improperly canned foods, fresh produce, and occasionally fish may carry the bacteria.

Poisoning in Peoria

"I'll have a patty melt on toasted rye, with American cheese and sautéed onions." With those words, 28 patrons in a Peoria, Illinois, restaurant unknowingly exposed themselves to botulism. Without seeing, tasting, or smelling anything unusual, they ate a toxin produced by bacteria spores growing on the onion skins. But these customers were fortunate. They were all hospitalized for treatment and went home healthy.

What Is Botulism?

Botulism is a rare but serious kind of food poisoning. Most outbreaks are caused by improperly preserved home-canned foods, but some are caused by improperly cooked foods.

Adults and infants are affected differently. In adults, botulism usually is caused by eating the toxin that already has been produced by Clostridium botulinum bacteria in the food. In infants, the toxin is produced in the intestine after eating the spores ^* of the bacteria. Honey is one of the primary sources of infant botulism.

Signs and Symptoms

The symptoms of botulism usually appear 12 to 36 hours after eating the affected food, but the onset can range between 6 hours and 8 days. Blurred vision, difficulty swallowing, body weakness, dry mouth, abdominal pain, vomiting, shortness of breath, and muscle paralysis can occur. Infants with botulism may show signs of weakness, constipation, and breathing difficulties. When death occurs, it is usually caused by paralysis of the respiratory muscles.

Diagnosis

Doctors diagnose botulism by noting the symptoms and conducting laboratory tests on blood or stool to detect the toxin. A doctor might ask about a patient's diet to try to determine the source and possibly test a sample of the suspect food. A brain scan, spinal fluid examination, or electromyography, which measures the activity of the muscles, can be used to help diagnose botulism or to rule out other causes of the symptoms.

Treatment

People who have botulism need to be hospitalized, especially to monitor and support their breathing. The doctor might try to get the poison out of the patient's body by inducing vomiting, rinsing out the stomach, or giving a laxative to flush out the intestines. Adults can be given an antitoxin to counteract the effects of the poison if the diagnosis is made early, within about 72 hours. About 100 cases of botulism occur every year in the United States. Despite improved treatment, 10 to 25 percent of people with botulism still die.

Prevention

Cooking food at high temperatures and using a pressure cooker when canning fruits and vegetables are the best ways to prevent botulism. The toxin can be destroyed by boiling for 10 minutes. Cooked foods should not be left out of the refrigerator for more than 2 hours. Throw out any food that shows signs of spoilage or any cans that are swollen or leaking. To prevent infant botulism, children younger than 1 year old should not eat honey.