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SECTION I - INFECTIOUS AGENT
NAME: Epidermophyton floccosum, Microsporum spp., Trichophyton spp.
SYNONYM OR CROSS REFERENCE: Dermatophytes, Dermatomycosis, Tinea, Ringworm, Epidermophytosis, Trichophytosis,
Microsporosis.
CHARACTERISTICS: Form hyphae and arthrospores in keratinized tissue, develop characteristic colonies and
conidia in culture, sexual spores in some species.
SECTION II - HEALTH HAZARD
PATHOGENICITY: Mycotic disease of keratinized areas of the body (hair, skin and nails) and of variable
severity depending on genera and species of dermatophyte; usually scaling or hair loss or breakage, sometimes erythema,
induration, crusting or suppuration; lesions often circular or annular because of central healing.
EPIDEMIOLOGY: Worldwide, relatively frequent; more common in hot, humid climates with crowding or debilitation;
season prevalence varies with age.
HOST RANGE: Humans, domestic and wild animals (depending on genera and species of dermatophyte - host specific).
INFECTIOUS DOSE: Unknown.
MODE OF TRANSMISSION: Contact of minor traumatized skin site with infected individual or fomites contaminated
with desquamated epithelium.
INCUBATION PERIOD: 5-12 days.
COMMUNICABILITY: Communicable as long as infective lesions are present and viable.
SECTION III - DISSEMINATION
RESERVOIR: Humans (anthropophilic); animals (zoophilic); soil (geophilic).
ZOONOSIS: Yes; farmers, livestock handlers, laboratory workers, and persons who milk infected animals are
at greater risk.
VECTORS: None
SECTION IV - VIABILITY
DRUG SUSCEPTIBILITY: Griseofulvin, miconazole, clotrimazole - depending on agent.
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 1% sodium hypochlorite (20% commercial bleach), phenolics,
glutaraldehyde, formaldehyde; susceptibility to 70% ethanol questionable.
PHYSICAL INACTIVATION: Inactivated by moist heat (121oC for at least 15 min).
SURVIVAL OUTSIDE HOST: Agents survive for months to years in dry, cool, shaded areas.
SECTION V - MEDICAL
SURVEILLANCE: Monitor for symptoms; confirm by microscopic examination of scrapings.
FIRST AID/TREATMENT: Bathing with soap and water and topical application of appropriate fungicide, griseofulvin
for scalp involvement and for infections unresponsive to topical agents.
IMMUNIZATION: None
PROPHYLAXIS: None
SECTION VI - LABORATORY HAZARDS
LABORATORY-ACQUIRED INFECTIONS: Sixth most commonly reported lab-acquired infection; 161 reported cases
most frequently associated with T. mentagrophytes; most acquired through contacts with naturally or experimentally
infected laboratory animals (mice, rabbits, guinea pigs) and rarely, with handling cultures.
SOURCES/SPECIMENS: Skin, hair, and nails of human and animal hosts.
PRIMARY HAZARDS: Contact with infected laboratory animals with inapparent or apparent infections.
SPECIAL HAZARDS: None
SECTION VII - RECOMMENDED PRECAUTIONS
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for all laboratory
and experimental animal activities with dermatophytes.
PROTECTIVE CLOTHING: Laboratory coat; gloves when handling infected materials.
OTHER PRECAUTIONS: Good sanitation, cleaning and disinfection important.
SECTION VIII - HANDLING INFORMATION
SPILLS: Allow aerosols to settle; wearing protective clothing, gently cover spill with paper towels and
apply sodium hypochlorite, starting at perimeter and working towards the center; allow sufficient contact time
(30 min) before clean up.
DISPOSAL: Decontaminate before disposal; steam sterilization, incineration, chemical disinfection.
STORAGE: In sealed containers that are appropriately labeled.
Date prepared: October 11, 1997 Prepared by: Canadian Office of Biosafety Information edited by the Colorado State
University Office of Biosafety; June 16, 1998.
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