NAME: Clostridium tetani
SYNONYM OR CROSS REFERENCE: Lockjaw, tetanus
CHARACTERISTICS: Gram positive sporeforming rod; single, spheric, terminal endospore; clubbed appearance; strict anaerobe; swarming on blood agar grown anaerobically; produces an exotoxin (tetanospasmin)
PATHOGENICITY: An acute disease induced by a neurotoxin; painful muscular contractions, primarily of neck muscles, secondarily of trunk muscles; abdominal rigidity, generalized spasms; 30-90% case fatality rate
EPIDEMIOLOGY: Worldwide; sporadic and relatively uncommon in North America and industrial countries; more common in agricultural regions and underdeveloped areas where contact with animal excreta is likely and immunization is inadequate; important cause of death in tropical areas; drug addict cases
HOST RANGE: Humans, animals
INFECTIOUS DOSE: Toxin is extremely potent
MODE OF TRANSMISSION: Tetanus spores introduced into the body through a wound contaminated with soil, street dust or feces, or injected street drugs; also through lacerations, burns and trivial wounds
INCUBATION PERIOD: Usually 3-21 days; average 10 days; shorter incubation periods are associated with more heavily contaminated wounds
COMMUNICABILITY: Not directly transmitted from person to person
RESERVOIR: Intestine of animals and humans; soil contaminated with animal and rarely human feces
ZOONOSlS: Yes - wound contamination with soil or feces (agricultural workers subject to cuts, especially where herbivore animals are raised)
VECTORS: None
DRUG SUSCEPTIBILITY: Generally susceptible to many antibiotics, including penicillin G, chloramphenicol, metronidazole, piperacillin and imipenem
DRUG RESISTANCE: Resistant to the aminoglycosides
SUSCEPTIBILITY TO DISINFECTANTS: Spores are resistant to many disinfectants; moderately susceptible to sodium hypochlorite; susceptible to high level disinfectants such as glutaraldehyde with a prolonged contact time
PHYSICAL INACTIVATION: Spores are fairly resistant to heat but are destroyed after 15 min contact with moist heat (121°C)
SURVIVAL OUTSIDE HOST: Manure - several days; soil - spores survive long periods; textiles - 730 days
SURVEILLANCE: Monitor for symptoms; no detectable antibody response and organism is rarely recovered from site of infection
FIRST AID/TREATMENT: Tetanus immune globulin (TIG) as soon as possible following the wound; if not available, tetanus antitoxin (equine origin) following testing for hypersensitivity; wound should be debrided and excised; mechanically assisted respiration may be necessary
IMMUNIZATION: Active immunization with adsorbed tetanus toxoid; generally administered together with diphtheria toxoid administered at l0-year intervals
PROPHYLAXIS: Prophylaxis in wound management: booster dose of toxoid if more than 10 years have elapsed; passive immunization with TIG; depends on whether wound is clean or contaminated, the immune status of patient. Antibiotics not effective
LABORATORY-ACQUIRED INFECTIONS: Risk is low; 5 incidents related to exposure of personnel during manipulation of toxin
SOURCES/SPECIMENS: Clinical specimens - wound exudates
PRIMARY HAZARDS: Accidental parenteral inoculation and ingestion of the toxin; it is unclear whether tetanus toxin can be absorbed through mucous membranes; hazards associated with aerosols and droplets are not fully understood
SPECIAL HAZARDS: None
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for activities involving the manipulation of cultures or toxin
PROTECTIVE CLOTHING: Laboratory coat; gloves when direct contact with infectious materials is unavoidable
OTHER PRECAUTIONS: None
SPILLS: Allow aerosols to settle; wear protective clothing; gently cover spill with paper towels and apply a suitable disinfectant (high level for spores, or 1% sodium hypochlorite), starting at perimeter and working towards the centre; allow sufficient contact time (30 min) before clean up
DISPOSAL: Decontaminate before disposal; steam sterilization, chemical disinfection, incineration
STORAGE: In sealed containers that are appropriately labelled
Date prepared: January 2000
Prepared by: Office of Laboratory Security, PHAC
Although the information, opinions and recommendations contained in this Material Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Copyright ©
Health Canada, 2001
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