Frequently Asked Questions
What is Clostridium perfringens?
Clostridium perfringens (C. perfringens) is a spore-forming gram-positive bacterium that is found in many environmental sources as well as in the intestines of humans and animals. C. perfringens is commonly found on raw meat and poultry. It prefers to grow in conditions with very little or no oxygen, and under ideal conditions can multiply very rapidly. Some strains of C. perfringens produce a toxin in the intestine that causes illness.
How common is C. perfringens food poisoning?
C. perfringens is one of the most common causes of foodborne illness in the United States. It is estimated that it causes nearly a million cases of foodborne illness each year.
What are the symptoms of C. perfringens food poisoning?
Persons infected with C. perfringens develop diarrhea and abdominal cramps within 6 to 24 hours (typically 8-12). The illness usually begins suddenly and lasts for less than 24 hours. Persons infected with C. perfringens usually do not have fever or vomiting. The illness is not passed from one person to another.
Who is at risk of C. perfringens food poisoning?
Everyone is susceptible to food poisoning from C. perfringens. The very young and elderly are most at risk of C. perfringens infection and can experience more severe symptoms that may last for 1-2 weeks. Complications including dehydration may occur in severe cases.
How is C. perfringens infection diagnosed?
Laboratories diagnose C. perfringens food poisoning by detecting a type of bacterial toxin in feces or by tests to determine the number of bacteria in the feces. A count of at least 106 C. perfringens spores per gram of stool within 48 hours of when illness began is required to diagnose infection.
How is C. perfringens treated?
Oral rehydration or, in severe cases, intravenous fluids and electrolyte replacement can be used to prevent or treat dehydration. Antibiotics are not recommended.
What causes C. perfringens food poisoning?
Although C. perfringens may live normally in the human intestine, illness is caused by eating food contaminated with large numbers of C. perfringens bacteria that produce enough toxin in the intestines to cause illness. C. perfringens spores can survive high temperatures. During cooling and holding of food at temperatures from 54°F–140°F (12°C -- 60°C), the spores germinate and then the bacteria grow. The bacteria grow very rapidly between 109°F-- 117°F (43°C --47°C). If the food is served without reheating to kill the bacteria, live bacteria may be eaten. The bacteria produce a toxin inside the intestine that causes illness.
What are common food sources of C. perfringens?
Beef, poultry, gravies, and dried or pre-cooked foods are common sources of C. perfringens infections. C. perfringens infection often occurs when foods are prepared in large quantities and kept warm for a long time before serving. Outbreaks often happen in institutions such as hospitals, school cafeterias, prisons, and nursing homes, or at events with catered food.
How can C. perfringens food poisoning be prevented?
To prevent the growth of C. perfringens spores that might be in food after cooking, foods such as beef, poultry, gravies, and other foods commonly associated with C. perfringens infections should be cooked thoroughly to recommended temperatures, and then kept at a temperature that is either warmer than 140°F (60°C) or cooler than 41°F (5°C); these temperatures prevent the growth of C. perfringens spores that might have survived the initial cooking process. Meat dishes should be served hot right after cooking. Leftover foods should be refrigerated at 40°F or below as soon as possible and within two hours of preparation. It is okay to put hot foods directly into the refrigerator. Large pots of food like soup or stew or large cuts of meats like roasts or whole poultry should be divided into small quantities for refrigeration. Foods should be covered to retain moisture and prevent them from picking up smells from other foods. Leftovers should be reheated to at least 165°F (74°C) before serving. Foods that have dangerous bacteria in them may not taste, smell, or look different. Any food that has been left out too long may be dangerous to eat, even if it looks okay.
Grass, JE, LH Gould, and BE Mahon. 2013. Epidemiology of Foodborne Disease Outbreaks Caused by Clostridium perfringens, United States, 1998-2010. Foodborne Pathogens and Disease. 2013. 10: 131-6.