NAME: Legionella pneumophila
SYNONYM OR CROSS REFERENCE: Legionnaires' disease, Legionellosis, Legionnaires' pneumonia, Pontiac fever
CHARACTERISTICS: Gram-negative rod, poorly stained, aerobic, difficult to grow in vitro, serogroups 1-18
PATHOGENICITY: An acute pneumonitis associated with anorexia, malaise, myalgia, headache, fever and chills, nonproductive cough, abdominal pain and diarrhea; case fatality rate of 39-50% in hospitalized cases; Pontiac fever - not associated with pneumonia, recovery within 5 days
EPIDEMIOLOGY: First documented outbreak in 1957 in US; identified in North America, Africa, Australia and Europe; sporadic cases and outbreaks more common in summer and autumn; causes 2-15% of all community-acquired pneumonias requiring hospitalization; legionellosis attack rate - 0.1-5%, Pontiac fever rate -95%
HOST RANGE: Humans; experimental infection in guinea pigs and embryonated chicken eggs; challenged rabbits develop antibodies but not clinical disease; mice are refractory to parenteral exposure
INFECTIOUS DOSE: Not known
MODE OF TRANSMISSION: Epidemiologic evidence supports aerosol transmission; other modes are possible including aspiration of water
INCUBATION PERIOD: Legionnaires' disease - 2-10 days, most often 5-6 days; Pontiac fever - 5-66 hours, most often 24-48 hours
COMMUNICABILITY: Person-to-person transmission has not been documented; animal to animal transmission shown not to occur in a variety of experimentally infected mammalian and avian species
RESERVOIR: Aqueous - hot water systems, air-conditioning cooling towers, evaporative condensers, respiratory therapy devices, hot and cold water taps, showers, creeks, ponds; soil has been suspected
ZOONOSIS: None
VECTORS: None
DRUG SUSCEPTIBILITY: Sensitive to erythromycin and rifampin, ciprofloxacin;
DRUG RSESISTANCE: Resistant to penicillin, cephalosporins, and aminoglycosides
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to many disinfectants - 1% sodium hypochlorite, 70% ethanol, glutaraldehyde, formaldehyde
PHYSICAL INACTIVATION: Susceptible to moist heat (121° C for at least 15 min) and dry heat (160-170° C for at least 1 hour)
SURVIVAL OUTSIDE HOST: Survives for months in tap or distilled water
SURVEILLANCE: Monitor for symptoms; confirm by isolation of organism for respiratory samples; rise in lFA titre
FIRST AID/TREATMENT: Hypoxic patients should receive oxygen; fluid replacement; antibiotic therapy
IMMUNIZATION: None
PROPHYLAXIS: Antibiotic prophylaxis
LABORATORY-ACQUIRED INFECTIONS: One documented case due to aerosol exposure during animal challenge studies
SOURCES/SPECIMENS: Pleural fluids, tissue, sputum, environmental sources (cooling tower water)
PRIMARY HAZARDS: Generation of aerosols during the manipulation of culture or other concentrations of infectious materials (eg. infected yolk sacs and tissues)
SPECIAL HAZARDS: When working with respiratory cultures, Francisella tularensis can mimic the growth requirements of Legionella
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for all activities involving the known or potentially infectious clinical materials or cultures and the housing of infected animals
PROTECTIVE CLOTHING: Laboratory coat; gloves when direct contact with infectious materials is unavoidable; gloves and gown for work in biosafety cabinet
OTHER PRECAUTIONS: Primary containment devices and equipment (biological safety cabinets, centrifuge safety cups) should be used for activities likely to generate potentially infectious aerosols
SPILLS: Allow aerosols to settle; wear protective clothing; gently cover spill with paper towels and apply 1% sodium hypochlorite, starting at perimeter and working towards the centre; allow sufficient contact time (30 min)
DISPOSAL: Decontaminate before disposal - steam sterilization, chemical disinfection, incineration
STORAGE: In sealed containers that are appropriately labelled
Date prepared: March, 2001
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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