NAME: Blastomyces dermatitidis
SYNONYM OR CROSS REFERENCE: Blastomycosis, Gilchrist's disease
CHARACTERISTICS: Dimorphic fungus; yeast stage (characteristic broad based budding form) in tissues and in enriched culture media at 37°C; mold stage with branching hyphae and ovoid conidia at room temperature
PATHOGENICITY: Granulomatous mycosis, primarily of the lungs (acute or chronic) or skin; indolent onset evolving into chronic pulmonary infection more common; skin lesions most commonly located on face and distal extremities; untreated disseminated or chronic pulmonary blastomycosis usually results in death
EPIDEMIOLOGY: Uncommon; occurs sporadically in central and southern eastern USA, Canada, Africa, India, Israel and Saudi Arabia; rare in children; more frequent in males than in females
HOST RANGE: Humans, dogs; also reported in cats, a horse, captive lion and sea lion
INFECTIOUS DOSE: Unknown
MODE OF TRANSMISSION: Inhalation of dust laden with conidia of mold or saprophytic growth form
INCUBATION PERIOD: Indefinite; probably a few weeks or less to months
COMMUNICABILITY: Not transmitted directly from person to person or from animals to people
RESERVOIR: Moist soil and decomposing organic material
ZOONOSIS: Not transmitted from animals to humans
VECTORS: None
DRUG SUSCEPTIBILITY: Sensitive to amphotericin B, itraconazole
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 1% sodium hypochlorite, phenolics, glutaraldehyde, formaldehyde, 10% formalin; susceptibility to 70% ethanol questionable
PHYSICAL INACTIVATION: Inactivated by moist heat (121°C for 15 min)
SURVIVAL OUTSIDE HOST: Spores are resistant and may survive for long periods in soil and dust
SURVEILLANCE: Monitor for symptoms; confirm by microscopic examination of sputum and material from lesions
FIRST AID/TREATMENT: Treatment with amphotericin B and/or itraconazole, ketoconazole
IMMUNIZATION: None
PROPHYLAXIS: None
LABORATORY-ACQUIRED INFECTIONS: 11 reported cases with 2 deaths - following accidental parenteral inoculation with infected tissue or cultures containing yeast forms, pulmonary infection following inhalation of conidia and subsequent development of osteolytic lesion
SOURCES/SPECIMENS: Yeast forms may be present in tissues of infected animals and in clinical specimens; mold form cultures
PRIMARY HAZARDS: Parenteral inoculation of yeast forms; inhalation of infectious conidia from mold forms
SPECIAL HAZARDS: Soil and other environmental materials may contain infectious conidia
CONTAINMENT REQUIREMENTS: Biosafety level 3 practices, containment equipment and facilities for processing mold cultures, soil and other materials known or likely to contain infectious conidia
PROTECTIVE CLOTHING: Laboratory coat; gloves and gown with tight wrists and ties in back when working with the agent
OTHER PRECAUTIONS: Appropriate precautions and practices to minimize the production of infectious aerosols
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 centre; 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 labelled
Date prepared: November 1999
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