Legionellosis

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Legionellosis

• Gregory M. Heck MPH, CSP, REHS
• Environmental Health Officer
• Phoenix Area Indian Health Service

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JCAHOEC.1.7i Utility Management Plan

• The plan provides processes for managing
  pathogenic biological agents in cooling towers,
  domestic hot water, and other aerosolizing water
  systems.
• In part, EC 1.7 states that a management plan
  must be in place to reduce the potential for
  hospital-acquired infection.

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History of Legionella

• 1976 American Legion Convention at Philadelphias
  Bellevue Stratford Hotel
• Illness struck 221 persons in or near the hotel.
  34 people died.
• CDC identified offending organism one year later.
• Organism had been around for decades. 1965
  hospital outbreak 81 developed pneumonia, 14
  died. Frozen specimens confirmed Legionnella
  bacteria was the cause.

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Legionellosis

• CDC estimates 8,000 to 18,000 people get
  Legionnairess disease each year.
• Estimates of 5 to 30 who have Legionnaires
  disease die.
• Legionellosis is an infection caused by the
  bacterium Legionella pneumophila.

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Comparison to Anthrax

• 22 total cases in 2001. Normally about 5 cases
  are seen in a year. Biological terrorism was
  responsible for the significant increase.
• 11 cases of inhalation anthrax (7 confirmed, 4
  suspect) were reported in 2001.
• Since 1955, there were 236 reported cases of
  anthrax, most of them cutaneous.

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Legionellosis

• Two distinct forms exist
• LegionnairesDisease, the more severe form which
  includes pneumonia
• Pontiac fever, a milder illness

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LegionellosisSymptoms

• Legionnaires Disease fever, chills, and a
  cough. Some patients may have muscle aches,
  headache, tiredness, loss of appetite, and
  occasionally diarrhea. Chest x-rays may show
  pneumonia. The kidneys may not function
  properly.
• Pontiac Fever fever and muscle aches. No
  pneumonia. Persons recover without treatment.

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LegionellosisMode of Transmission

• Outbreaks have occurred after persons have
  breathed mists that come from a water source
  contaminated with Legionella bacteria. At least
  39 species have been identified.
• Legionella pneumophila species has been
  responsible for 85 to 90 percent of all cases of
  legionellosis.
• It is not passed on person to person.

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LegionellosisIncubation Period

• Legionnaires Disease 2 to 10 days
• Pontiac Fever 48 to 72 hours
• Case definition single case of laboratory
  confirmed Legionnaires Disease that occurs in a
  patient who has been hospitalized continuously
  for gt 10 days before onset. Two or more cases of
  laboratory confirmed infections that occurs 2 9
  days after admission with 6 months of each other.

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LegionellosisSources

• cooling towers
• whirlpool spas
• domestic water system shower heads aerators
• decorative fountains misters
• HVAC humidifiers HVAC ductwork
• Nebulizers other respiratory-care equipment.
• Warm, stagnant water

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LegionellosisWater Conditions for Growth

• Organism multiplies between 68 and 122 degrees F.
  Temperatures of 90 to 105 degrees F are ideal.
• Rust, scale, and other microorganisms (e.g.,
  protozoa) can promote the growth of Legionella
  bacteria.

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LegionellosisPatient Risk Factors

• Age older persons more at risk
• Heavy smokers
• Weakened immune system (cancer patient, HIV
  infected individual)
• Underlying medical condition diabetes, renal
  dialysis
• Certain drug therapies corticosteroids
• Heavy consumption of alcohol

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LegionellosisPrimary Prevention - Education

• Physicians need to heighten their suspicion for
  cases of nosocomial Legionnaires Disease. It is
  estimated that 3 of all pneumonias are caused by
  Legionella bacterium.
• Patient Care, Infection Control and Engineering
  need to be educated about measures to control
  nosocomial legionellosis.

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Control of LegionellosisPrimary Prevention -
Surveillance

• Mechanisms must be in place so that clinicians
  have appropriate laboratory tests for the
  diagnosis of this disease.
• The diagnosis requires special tests not
  routinely performed on persons with fever or
  pneumonia.
• These tests may involve testing sputum, urine and
  blood.

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Control of LegionellosisPrimary Prevention -
Nursing Practices

• Using sterile water for rinsing nebulization
  devices and other semi-critical respiratory-care
  equipment after they have been cleaned and
  disinfected.
• Using sterile (not distilled, nonsterile) water
  to fill reservoirs and devices used for
  nebulization.
• Do not use large-volume room-air humidifiers that
  create aerosols, unless they can be sterilized or
  subjected to high-level disinfection daily and
  filled with sterile water.

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Control of LegionellosisPrimary Prevention
Activities

• Ice machines should be cleaned and sanitized per
  current manufacturers recommendations.
• The PT Department to ensure whirlpool units and
  tubs are cleaned and disinfected according to the
  manufacturers instructions or CDCs guidelines.
• Dentists should maintain the water quality of
  their units per manufacturer recommendations and
  follow guides of The Organization of Safety
  Asepsis Procedures (OSAP). Sterile water should
  be used for sterile irrigations. High speed
  water lines should be run before procedures and
  before the start of each clinic day.

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Control of LegionellosisPrimary Prevention -
Cooling Towers

• Install drift eliminators where applicable.
• Regular treatment with effective biocides.
• ASHRAE recommends alternating the biocides using
  oxidizing and non-oxidizing biocides to prevent
  resistant strains of microbes.
• Conduct weekly inspections to identify and fix
  leaks, check for corrosion, deterioration and
  blockages and ensure equipment (fans, motors
  pumps) are operating properly.

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Control of LegionellosisPrimary Prevention - HVAC

• Ensure drip pans on all HVAC units drain well and
  are kept clean.
• Ductwork should be designed so water from
  condensation and other sources does not
  accumulate.
• Drain lines should include a trap and air break
  to prevent contaminated water from being drawn
  into the system.
• Steam humidification is recommended where
  humidification is provided. See AIA guidelines
• Evaporative coolers are regularly inspected
  maintained.

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Control of LegionellosisPrimary Prevention

• Ensure decorative fountains are cleaned on a
  routine basis and regularly disinfected.
  Decorative fountains should not be located in
  patient care areas.
• Ensure eyewash stations and emergency showers are
  flushed weekly.
• Misters, including plant misters, should not be
  used in healthcare environments.

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Control of LegionellosisPrimary Prevention

• All new tanks and piping should be disinfected
  with chlorine prior to start-up.
• Identify all dead end piping. Piping that serves
  patients at risk should either be replaced or a
  scheduled flushing of stagnant water should be
  initiated.

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Control of LegionellosisPrimary Prevention
-Water Lines Fixtures

• Avoid washers and gaskets made of natural rubber.
  Neoprene or other synthetics are recommended.
• Replace heavily scaled faucets and showerheads.
• Avoid faucet aerators.
• Avoid shock absorbers (water hammer arrestors)
• Treat water to prevent the accumulation of scale.
• Choose copper pipe over other materials. Copper
  resists Legionellae colonization. Steel is
  second best. Plastics are the worst.

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Control of LegionellosisPrimary Prevention -
Water Lines Fixtures

• To the extent possible, require plumbing
  contractors to
• Extend recirculation lines to the point farthest
  from the supply
• Run hot piping above cold piping to prevent
  warming of cold water.
• Ream pipe ends to remove burrs. Apply pipe
  compound only to male threats.
• Run all lines at a slight fall to make draining
  the system easier to reduce air locks.

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Legionnaires DiseaseResponse to Case

• Conduct epidemiological and environmental
  investigation to determine source.
• Confirm case evaluate medical record and
  microbiological data.
• Active surveillance should be initiated
• Identify potential risk factors
• Collect water samples from implicated
  environmental sources.
• Subtype-matching between organism isolated from
  patients and environmental samples.

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Legionnaires DiseaseResponse to Case

• If source of infection is identified by
  epidemiological and environmental investigation,
  promptly decontaminate it.
• Water system decontaminate heated-water system
  by superheating or by hyperchlorination. Risks
  of scalding where hot water is used. Try and
  maintain 1 to 2 mg/L free residual chlorine after
  treatment at the tap where patients are at high
  risk.
• Try and keep cold water below 68 degrees F.

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Legionnaires DiseaseResponse to Case Water
System

• Restrict immune compromised patients from taking
  showers.
• Use only sterile water for their oral consumption
• For high risk patients, remove shower heads and
  faucet aerators monthly for cleaning and
  disinfecting.

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Legionnaires DiseaseWater Treatment Methods

• Heat and flush (heat shock)
• Superchlorination followed by continuous
  disinfection.
• Copper-silver ionization 0.4 ppm of copper and
  0.04 of silver were best for killing legionellae.
  These are below the EPA drinking water maximum
  of 1.3 ppm copper and 0.1 silver.
• Ultraviolet radiation good for small portions
  of a system (closed loop that recirculates)
• Ozonation difficult to find performance report.
• Chlorine Dioxide currently being tested for
  efficacy in water distribution system.

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Response to CaseCooling Towers

• Decontaminate per current manufacturers
  recommendations.
• In the absence of manufacturer recommendations,
  the CDC Guidelines for Prevention of Nosocomial
  Pneumonia, Appendix D, has procedures for
  cleaning cooling towers and related equipment.

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Legionnaires DiseaseFollow-up Activities

• Evaluate if control measures are working.
• Collect samples for culture at 2-week intervals
  for 3 months. If not detected, collect cultures
  monthly for another 3 months.
• If Legionella species are detected in one or more
  cultures, reassess control measures, modify
  accordingly and repeat decontamination process.
• Keep records of all control measures and
  laboratory tests.

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Worker Safety

• Workers involved in decontamination procedures
  shall receive training on legionellosis and
  safety precautions.
• Hazard Communication
• Personal Protective Equipment
• Respiratory Protection. (N-100 or HEPA)
• See OSHA Technical Manual, Section III, Chapter
  7. www.osha.gov

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References and Resources

• www.cdc.gov (CDC will be publishing Guidelines
  for Environmental Infection Control and
  Prevention in Healthcare Facilities in the near
  future)
• www.osha.gov
• www.ashrae.org
• www.ashe.org
• www.hcinfo.com
• www.osap.org