1. Legionella Matt Zahn, MD Medical Director Epidemiology and Assessment
Orange County Health Care Agency
August 11, 2015

2. Bronx, New York Outbreak of Legionella
Reported individuals with Legionnaires': 113
Individuals treated and discharged: 76
Individuals with Legionnaires' deceased: 12
All deceased individuals were adults with underlying medical conditions
No new deaths have been reported in the last six days.
No new cases diagnosed since August 3.

3. New York City Messaging: Safety of Water Supply and Air Conditioning
11 sites have tested positive within the community impact zone
“Health officials remain confident that the source of the outbreak is from a location in the initial round of positive test sites, and that through disinfection of the source, the outbreak has been contained.”
New York City’s drinking water supply and other water features, like fountains, shower heads and pools, are safe
Water towers are unaffected by legionella
Home air conditioner units are unaffected

5. Legionella History
1976: First recognized after outbreak of pneumonia in attendees of American Legion convention in Philadelphia
Pontiac fever
Named for Pontiac, Michigan
In 1968, several workers at the county's department of health came down with a fever and mild flu symptoms, but not pneumonia. After the 1976 Philadelphia event, the Michigan health department re-examined blood samples and identified Legionella as the pathogen
1980: First case of hospital-acquired Legionnaires’ Disease

6. Legionellosis Epidemiology
Estimated ,000 cases/year in US (2000/year reported)
Under-diagnosed
Estimated 2-15% of community-acquired pneumonia
Fatality 8% ( 5-30%)
Legionellosis-United States, 2000—
2009, MMWR, WeeklyAugust 19, 2011 / 60(32);

7. Legionella in California

8. Legionella in California

9. Orange County Legionellosis
Number of Cases

10. Legionella species Poorly staining gram-negative bacilli
Does not grow on routine culture media
Over 40 species
Legionella pneumophila serogroup 1 causes 80-90% of identified clinical infections

11. Legionella Disease Spectrum
Pontiac Fever
Pneumonia (Legionnaires’ Disease)

12. Pontiac Fever Self-limited influenza-like illness
No lower respiratory tract involvement
Incubation period 5-66 hrs
Usually hrs
Attack rate: high ( 50-90%)

13. Legionnaires’ Disease
Fever and lower respiratory tract disease
Pneumonia
LFT elevation common
Incubation period 2-10 days
Usually 5-6 days
Mortality: 8% (5-30%)
Attack rate: <5%

14. Legionnaires’ Disease Diagnosis
Culture (requires special media)
Urinary antigen
Detects Legionella pneumophila serogroup 1
Sensitivity: 60%--80%; specificity >99%
Paired serologies
DFA
PCR

15. Legionellosis Treatment
Quinolones or Macrolides
Add Rifampin if severe disease

16. CDPH Legionella Case Definition
Clinical symptoms compatible with Legionella
AND
Confirmatory Laboratory Test:
Urinary Antigen OR
Culture OR
Validated positive PCR OR 
DFA OR
Serology—fourfold increase from baseline

17. Legionella Transmission
Primary route: inhalation of an aerosol containing
Some cases due to ingestion of contaminated water and subsequent aspiration or pharyngeal colonization
Not transmitted from person-to-person

18. Host Risk factors Immune compromised, especially cellular immunity
Age >50 years
Smoker
Chronic lung disease
Diabetics

19. Exposure Risk Factors Travel: overnight stay outside of home
Exposure to aerosols of potable water
Recent plumbing repairs or maintenance work
CDC categories:
Travel-associated
Healthcare-associated
Community-acquired

20. Legionella in the Environment
Commonly present in potable water
Man-made freshwater environments
Live in symbiosis with amoebae in the biofilm that lines water-containing pipes and tanks
Thrives in stagnant warm water ~25-42C (77-108F)

21. Legionella Reservoirs
Showers
Cooling towers
Whirlpools
Misters
Hot tubs/ whirlpool baths
Cooling towers
Hot water tanks
Humidifiers
Decorative fountains
Survives in cold temperatures, including in ice
Large plumbing system: dead legs/areas of stagnation

22. LADPH Surveillance Review
48 single cases
32 definite
16 possible
67 nosocomial
48 definite
19 possible
893 confirmed cases
19 cases: 8 outbreaks
16 definite
3 possible
D. Terashita, 2015

23. LADPH Surveillance Review
8% of all LAC legionellosis healthcare associated
28% of healthcare-associated cases are outbreak related
50% of subsequent healthcare-associated cases >2 months after index case
75% of environmental cultures + for Legionella
When patient and environmental serotypes matched, cases clustered tightly in time
When patient and environmental serotypes did not match or environmental cultures were negative, subsequent cases occur much later
D. Terashita, 2015

24. Transmission in Healthcare-Associated Legionellosis:
Hospital outbreaks attributed to inhalation from:
Showers
Faucets
Respiratory therapy equipment
Room-air humidifiers
Cooling towers
Medical center outbreak associated with decorative fountain in the lobby
Hospital outbreaks attributed to ingestion or aspiration of potable water and ice

25. CDC Case Definitions for Healthcare–Associated Legionellosis
Definite healthcare-associated:
Lab-confirmed and patient hospitalized (or residing in a healthcare facility) continuously for ≥10 days prior to symptom onset
Possible healthcare-associated:
Lab-confirmed and patient hospitalized (or residing in a healthcare facility) for a portion of the 2-9 days before onset of symptoms

26. Healthcare Associated Outbreak
CDC defines as:
≥2 healthcare‐associated case of same serotype
1 transplant associated case
Proposed CDC Best Practice in 2015:
Environmental investigation should be initiated after one DEFINITE healthcare-associated case

27. After One Suspect or Confirmed HA Legionella Case, CDPH Recommends:
Provide Guidance to facility
Review medical/microbiology records of past 6 months
Initiate active surveillance for at least 2 months
OCHCA recommends 3 months

28. Potential Immediate Control Measures - 2
Restrict patient showering
Restrict drinking from potable water sources (bottled water)
No ice from the ice machine
Turn off decorative water features and whirlpools and/or spas until cultures available/remediation completed
Ensure use of sterile water in water-based devices that produce aerosols (e.g., respiratory therapy equipment, and humidifiers)
Install point-of use filters for faucets and shower-heads if anticipate delay in assessment/remediation

29. Point of Use Filtration
May be a useful approach in a strategic set of faucets
Not practical solution for an entire hospital
Must be changed frequently

30. Legionella Testing Sites Per CDC Recommendations
Examples include, but not limited to:
Showers
Water faucets
Cooling towers
Hot-water tanks
Carpet cleaner water tank

31. Routine Testing of Water in Healthcare Facilities?
In 1992 study of 84 hospitals in Quebec:
At least one sample was positive from 67% of facilities
In a study of 11 healthcare facilities in Italy:
87% of water samples positive for Legionella species
No increase in cases noted
BUT
Multiple studies have found that culture positive results from water sources in HCFs match facility cases
Legionellosis is chronically underrecognized
Alary MA, JID, 1992
Legnani, JID, 1992

32. Recommendations for Routine Testing of Hospital Water Supplies for Legionella
CDC recommends culturing hospital water supplies for Legionella only in response to the identification of nosocomial infection
Hospitals performing organ transplantation are recommended to routinely test water for Legionella
Certain state and local health departments recommend a more proactive approach, with culture of the water system and active surveillance for cases if Legionella isolated
VA hospital system recommends routine quarterly testing of facilities
Allegheny local public health recommends environmental response if 30% or more environmental samples are positive
Several other nations, including the Netherlands, Germany, France, Denmark, and Taiwan, now mandate routine environmental surveillance for Legionella in hospitals

33. CDC Recommendations for Water Maintenance
A. Maintain hot water temperature at the return at the highest temperature allowable by state regulations or codes, preferably > 124ºF (> 51ºC), and maintain cold water temperature at <68ºF (<20ºC)
B. If the hot water temperature can be maintained at > 124ºF (> 51ºC), explore engineering options (e.g., installing preset thermostatic valves in point-of-use fixtures) to help minimize the risk of scalding
C. When state regulations or codes do not allow hot water temperatures above the range of 105ºF--120ºF (40.6ºC--49ºC) for hospitals or 95ºF--110ºF (35ºC--43.3ºC) for nursing care facilities or when buildings cannot be retrofitted for thermostatic mixing valves, follow either of these alternative preventive measures to minimize the growth of Legionella spp. in water systems: 1. Periodically increase the hot water temperature to > 150ºF (> 66ºC) at the point of use (153) 2. Alternatively, chlorinate the water and then flush it through the system ( )

34. Conclusions
Legionella healthcare-associated disease is a significant cause of morbidity and mortality
Legionellosis is underrecognized
Routine environmental testing for Legionella is of uncertain benefit
Aggressive response to HA outbreaks is paramount

35. In other news….

36. Ebola Two cases reported in week leading to August 2:
One in Sierra Leone
One in Guinea
OCHCA continues to follow travelers from all three impacted countries

37. MERS-CoV in the Republic of Korea
186 total cases associated with that country’s outbreak
Last confirmed case had illness onset of July 4
MERS-CoV should be considered in those with lower respiratory tract disease and:
Traveler from Korea and healthcare facility exposure
Travel from the Arabian peninsula

38. Orange County with First Confirmed West Nile Case of Season Last Week