# Presentation: 021597

## Legionellosis

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

## JCAHOEC.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.

## History of Legionella

- 1976 American Legion Convention at Philadelphia’s 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.

## Legionellosis

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

## 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.

## Legionellosis

- Two distinct forms exist:
- Legionnaires’Disease, the more severe form which includes pneumonia
- Pontiac fever, a milder illness

## LegionellosisSymptoms

- 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.

## LegionellosisMode 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.

## LegionellosisIncubation 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 _>_ 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.

## LegionellosisSources

- 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

## LegionellosisWater 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.

## LegionellosisPatient 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

## LegionellosisPrimary 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.

## Control of LegionellosisPrimary 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.

## Control of LegionellosisPrimary 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.

## Control of LegionellosisPrimary Prevention Activities

**Ice machines should  be cleaned and sanitized per current manufacturer’s recommendations.**
**The PT Department to ensure whirlpool units and tubs are cleaned and disinfected according to the manufacturer’s instructions or CDC’s 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.**

## Control of LegionellosisPrimary 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.

## Control of LegionellosisPrimary 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.**

## Control of LegionellosisPrimary 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.**

## Control of LegionellosisPrimary 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.**

## Control of LegionellosisPrimary 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.

## Control of LegionellosisPrimary 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.

## Legionnaires DiseaseResponse 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.**

## Legionnaires DiseaseResponse 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.

## Legionnaires DiseaseResponse 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.

## Legionnaires’ DiseaseWater 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.

## Response to CaseCooling Towers

- Decontaminate per current manufacturer’s 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.

## Legionnaires DiseaseFollow-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.

## 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](http://www.osha.gov/)_

## References and Resources

- _[www.cdc.](http://www.cdc.gov/)__[gov](http://www.cdc.gov/)_  (CDC will be publishing *Guidelines for Environmental Infection Control and Prevention in Healthcare Facilities* in the near future)
- _[www.osha.gov](http://www.osha.gov/)_
- _[www.ashrae.org](http://www.ashrae.org/)_
- _[www.ashe.org](http://www.ashe.org/)_
- _[www.hcinfo.com](http://www.hcinfo.com/)_
- _[www.osap.org](http://www.osap.org/)_