OPHEPR; Epsilon Toxin of Clostridium Perfringens - Profile for Healthcare Workers

Causative Agent: Clostridium perfringens is a Gram positive, anaerobic, toxin producing spore-forming rod that is commonly found in normal intestinal bacteria. It is a cause of wound infections and food poisoning in humans. C. perfringens spores are ubiquitous in the environment. When the spores are injected or inoculated into a wound, bacteria grow and produce toxins.

Epsilon toxin is one of the toxins of type B and type D strains of C. perfringens. Epsilon toxin has been suggested as a potential biological weapon. Epsilon toxin damages cell walls and causes potassium and fluid leakage from cells.

Routes of Exposure: C. perfringens usually causes infections in humans by contamination of food, or by inoculation into an open wound. Exposure to epsilon toxin could be spread by aerosolization or by adding it to food or water.

Infective Dose & Infectivity: C. perfringens is normal flora in the human intestinal tract. However, when large numbers of C. perfringens grow in inadequately stored food, or when it contaminates an open wound, clinical symptoms develop.

Incubation Period: The incubation period for gastrointestinal symptoms after oral ingestion of C. perfringens is usually 10-12 hours, with a range of 6-24 hours. The incubation period of epsilon toxin after respiratory or oral exposure is not known.

Clinical Effects: C. perfringens gastroenteritis can include diarrhea, nausea, severe abdominal cramps and bloating for 1-2 days. Vomiting and fever are not usually seen. Wound contamination can result in clostridial myonecrosis (gas gangrene), or clostridial cellulitis.

Type B and D strains, the strains that produce epsilon toxin, do not usually infect humans. C. perfringens type B causes severe gastroenteritis in young calves, foals, lambs and piglets. Type D causes enterotoxemia in sheep and goats. Intravenous injection of epsilon toxin animals has resulted in pulmonary edema and neurologic symptoms.

The symptoms in humans from intentional exposure to epsilon toxin is not known. Extrapolating from animal experiments, pulmonary edema, neurologic symptoms, or gastroenteritis could be seen.

Lethality: Death from naturally occurring C. perfringens infection is very rare. It is not known how lethal epsilon toxin would be as a bioterrorism agent.

Transmissibility: C. perfringens is ubiquitous in the environment. Transmission to humans is usually from environmental exposure rather than person-to-person spread. Toxins (such as epsilon toxin) are usually not transmitted from person to person.

Primary contaminations & Methods of Dissemination: In a bioterrorist attack, C. perfringens could be used to contaminate food or water supplies. Epsilon toxin could be spread in food, water, or by aerosolization.

Secondary Contamination & Persistence of organism: Since C. perfringens is so ubiquitous in the environment yet only causes disease in specific settings, secondary contamination would not be expected to be a problem. C. perfringens spores can survive in soil for long periods of time.

Decontamination & Isolation:

Patients – Standard precautions should be practiced. Specific isolation procedures are not indicated.
Equipment, clothing & other objects – Methods of decontamination for the epsilon toxin have not been published. Proteins are usually denatured by heat.

Laboratory testing: C. perfringens can be isolated from standard bacterial wound and stool cultures. Epsilon toxin can be detected by various assays including enzyme-linked immunosorbent assays (ELISA).

Therapeutic Treatment: Penicillin is the drug of choice for C. perfringens gastroenteritis and wound infection. Treatment for toxin exposure would likely be supportive.

Prophylactic Treatment: There is no vaccine available to protect against C. perfringens food poisoning or wound infection. There is no preventive measure against epsilon toxin used as a bioterrorism agent.

Differential Diagnosis: The differential diagnosis includes other recognized forms of food poisoning as well as aerosolized toxins and poisons.

References:

Chin J. Control of Communicable Diseases Manual, Seventeenth Edition, American Public Health Association; 2000.
Center for Food Safety and Applied Nutrition. Foodborne Pathogenic Microorganisms and Natural Toxins Handbook, U.S. Food and Drug Administration
Center for Food Security and Public Health. Epsilon toxin of Clostridium perfringens, Iowa State University College of Veterinary Medicine

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