NAME: Cryptosporidium parvum
SYNONYM OR CROSS REFERENCE: Cryptosporidiosis
CHARACTERISTICS: Coccidian protozoa; sporozoa; sexual and asexual cycles in a single host; sporozoites, trophozoites and merozoites all attach to epithelial cells (generally intestinal cells); mature oocyst contains 4 thin, flat motile sporozoites (2-4 by 6-8µm)
PATHOGENICITY: Characterized by profuse, watery diarrhea, cramping, abdominal pains, weight loss, anorexia, flatulence and malaise; nausea, vomiting, fever and myalgias may also be present; symptoms are self-limiting in healthy individuals; immunocompromised patients including AIDS patients may experience prolonged symptoms with increasing severity
EPIDEMIOLOGY: Worldwide; rate of infection ranges from 1 to 4.5% in developed countries and from 3 to 20% in developing countries; higher infection rates reported in AIDS patients (3-20% in US, 50-60% in Africa and Haiti); frequent outbreaks in daycare centres
HOST RANGE: Vertebrates including humans, poultry, fish, reptile, small and large mammals
INFECTIOUS DOSE: ID50=132 organisms (N Engl J Med 1995; 332:855-9)
MODE OF TRANSMISSION: Fecal-oral route (person-to-person, animal-to-person, food and waterborne transmission)
INCUBATION PERIOD: 1 to 12 days; average is 7 days
COMMUNICABILITY: Oocysts, the infectious stage, excreted in stools from onset of symptoms to several weeks after symptoms resolve
RESERVOIR: Humans, cattle and other domestic animals
ZOONOSIS: Yes - acquired through contact with contaminated animal fecal matter, particularly diarrhea
VECTORS: None
DRUG SUSCEPTIBILITY: No effective therapeutic agent available; cyclosporine inhibits Cryptosporidium growth in vitro
SUSCEPTIBILITY TO DISINFECTANTS: Resistant to most disinfectants including 3% hypochlorite, iodophors, 5% formaldehyde; prolonged treatment (18 hours) with 5% ammonia, 10% formol saline (formaldehyde plus sodium chloride) or 3% hydrogen peroxide reduces infectivity
PHYSICAL INACTIVATION: Heating at 65°C for 30 minutes reduces infectivity
SURVIVAL OUTSIDE HOST: Oocysts may survive for 2 to 6 months in a moist environment
SURVEILLANCE: Monitor for symptoms; confirm by microscopic examination of specimens, identification of oocysts in fecal smears
FIRST AID/TREATMENT: Administer supportive therapy and rehydration in normal individuals; spiramycin may decrease diarrheal symptoms in early infections; paromomycin has been effective in AIDS patients
IMMUNIZATION: None available
PROPHYLAXIS: None available
LABORATORY-ACQUIRED INFECTIONS: One case was reported in 1983 due to accidental inoculation; although not documented, infections are thought to occur regularly in all laboratories working with this organism (BMBL, 4th ed., 1999)
SOURCES/SPECIMENS: Feces, intestinal biopsy sections
PRIMARY HAZARDS: Ingestion; accidental parenteral inoculation; airborne transmission is also possible
SPECIAL HAZARDS: Naturally and experimentally infected animals pose a risk to laboratory and animal care personnel
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for all activities involving known or potentially infectious materials
PROTECTIVE CLOTHING: Laboratory coat; gloves when skin contact with infectious materials is unavoidable and when working with animals
OTHER PRECAUTIONS: Maintain good personal hygiene and frequent handwashing
SPILLS: Allow aerosols to settle; wearing protective clothing, gently cover spill with absorbent paper towel and apply 10% formol saline or 5 % ammonia, starting at the perimeter and working towards the centre; allow sufficient time (approximately 20 hours) before clean up
DISPOSAL: Decontaminate all wastes before disposal; steam sterilization, chemical disinfection, incineration
STORAGE: In sealed container that are appropriately labelled
Date prepared: August 2002
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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