Legionella. What is it and how do we treat it?

1. Legionella. What is it and how do we treat it?

2. Legionella – What is it? • Type of bacteria found in bodies of water • At least 39 species have been identified • More than 60 serogroups have been identified • Some serogroups have several subtypes

3. Legionella Pneumophila • Most common species of all • 15 serogroups • Serogroup 1 has at least 50 subtypes • Causes 85 to 90 percent of all cases

4. What is Legionaires’ Disease? • A multisystem illness with a deadly type of pneumonia • Named by the press to identify the unknown bacterium

5. Legionaires’ Disease • First identified – Bellevue-Stratford Hotel – Philadelphia, July of 1976 • Illness struck 221 people • 72 who did not attend the convention • 34 died

6. Did you know? • 2.4 million cases of pneumonia each year in the U.S. • 10,000 to 100,000 are cases of Legionaires’ disease • Only 1,000 to 3,000 are reported to CDC

7. Legionaires’ Disease • Cases go undetected due to lack of testing • Other cases missed because test procedures are not sensitive enough • Deaths from undetected cases classified as pneumonia with an unknown cause

8. Legionaires’ Disease • Most cases occur one or two cases at a time and not an outbreak • Sporadic cases generally not reported to the public • Overall opinion is that the problem is not that great

9. Legionaires’ Disease • Considered an environmental disease – water to people. Not communicable. • Transmission occurs when airborne water droplets containing Legionella are inhaled

10. The Risk of Infection is Based on Two Key Factors • The number of bacteria reaching the body • The resistance of the individual

11. Legionella – Where does it come from? • Poorly treated water • Poorly designed plumbing systems • Poorly treated plumbing systems

12. Primary Sources of Legionellae Bacteria • Domestic Hot Water Systems • Cooling Towers • Evaporative Condensers • Respiratory Care Equipment • Showers

13. Primary Sources of Legionellae Bacteria • Faucets • Whirlpool Baths • Humidifiers • Fountains • Grocery Store Produce Mister

14. Legionella – Where does it live? • Bacterial amplifiers • Biofilm within plumbing systems

15. Thermo- meter Heated Water Safety Relief Valve Temperature signal is “fed back” through capillary tube Temperature Reg Valve Liquid or Gas Filled Bulb P Storage Tank Steam Supply Recirculatin Pump V.B. F&T Trap Make Up Water Condensate Return Recirculated Water Storage Tank Feed-Back System

16. Legionellae and Temperature • Below 68°F legionellae can survive but are dormant • Legionellae growth range (68°F – 122°F) • Ideal growth range (95°F – 115°F) • Above 122°F legionellae can survive but do not multiply • At 131°F legionellae die within 5 to 6 hours • At 140°F legionellae die within 32 minutes • At 151°F legionellae die within 2 minutes • Disinfection range (158°F - 176°F)

17. Preventive Measures • Maintain mechanical and plumbing systems for the control of Legionella • If you are high risk for Legionella consider more costly measures to fix your systems and reduce the risks • Document all preventive measures to show you took responsible action

18. Environmental Samplings • CDC does not recommend regular water sampling • Negative results may create a false sense of security and positive results a false alarm • Sampling results, though sometime inconclusive, provide lifesaving information

19. Samplings – Yes or No? • Weigh value of information provided against the cost • Weigh the risk of misleading sampling against the risk of not sampling • Consider risk management • DO NOT use as a substitute for preventive measures

20. Methods of System Treatment • Superheat and Flush (thermal) • Feed-Forward Instantaneous Water Heaters (thermal) • Hyperchlorination (biocide) • Ultra Violet Rays (biocide) • Ozone (biocide) • Chlorine Dioxide (biocide) • Copper/Silver Ionization (biocide)

21. Superheat & Flush Positives • Inexpensive • Proven effective irrespective of water quality • Non aggressive to pipe work and fittings • Non toxic/consumable • No professionally qualified personnel required to administer treatment

22. Superheat & Flush Negatives • Potential scald risk • Non-effective unless sterilization temperature is achieved (biofilm) • Dead-legs may not permit adequate flushing

23. Temperature in F° 111.2 116.6 118.4 122.0 131.0 140.0 149.0 158.0 Time for 1st degree burn 5 hours 35 minutes 10 minutes 1 minute 5 seconds 2 seconds 1 second ------ Temperature/Time Burn Chart

24. What types of Water Heaters are on the market today? • Feed-Back Units: Operate on a differential of water TEMPERATURE • Feed-Forward Units: Operate on a differential of water PRESSURE

25. Thermo- meter Heated Water Safety Relief Valve Temperature signal is “fed back” through capillary tube Temperature Reg Valve Liquid or Gas Filled Bulb P Storage Tank Steam Supply Recirculatin Pump V.B. F&T Trap Make Up Water Condensate Return Recirculated Water Storage Tank Feed-Back System

26. Blended Water Out @ P2 Mixing Chamber “Over-heated” Water from tube bundle Valve #3 P1 P2 Valve #2 Supply Water In @ P1 Valve #1 Tube Bundle Feed-Forward Instantaneous Water HeaterControl Valve Schematic

27. Feed-Forward Instantaneous Water Heater Positives • Sterilizes water in the heat exchanger as a function of making hot water

28. Blended Water Out @ P2 Mixing Chamber “Over-heated” Water from tube bundle Valve #3 P1 P2 Valve #2 Supply Water In @ P1 Valve #1 Tube Bundle Feed-Forward Instantaneous Water HeaterControl Valve Schematic

29. Feed-Forward Instantaneous Water Heater Positives • Sterilizes water in the heat exchanger as a function of making hot water • Non aggressive to pipe work and fittings • Non toxic/consumable • No scald risk

30. Feed-Forward Instantaneous Water Heater Negatives • Water which bypasses the heat exchanger is not sanitized • Does not kill bacteria in the system biofilm

31. Hyperchlorination Positives • Inexpensive • Effectively kills bacteria in the water

32. Hyperchlorination Negatives • Hazardous material which requires trained operators in order to handle • The chemical is a carcinogen • Aggressive to pipe work and fittings • Does not kill bacteria in the biofilm

33. Ultra Violet Positives • Harmless and non-toxic • Effectively kills bacteria in the water

34. Ultra Violet Negatives • Expensive • Only effective at point of treatment • High maintenance cost – lamps wear out and are fragile and need replacement • Micro organisms can become resistant and repair UV damage • Does not kill the bacteria in the biofilm

35. Ozone Positives • Effectively kills bacteria in the water

36. Ozone Negatives • Difficult to maintain effective levels of ozone in the system – decomposes into water • High ozone levels may damage pipe • Not tested in facilities – its use would be pioneering • Does not kill the bacteria in the biofilm

37. Chlorine Dioxide Positives • Effectively kills bacteria in the water • Early indications show potential of killing bacteria in the biofilm as well as removal of biofilm

38. Chlorine Dioxide Negatives • Expensive • Concentration levels required often exceed health standards – health & safety issues • Aggressive to copper piping • Needs special storage – hazardous material • Chemical (Potassium, Chlorate and Hydrochloric Acid) is unstable – may explode • Professionally qualified personnel required

39. Copper/Silver Ionization Positives • Use of sacrificial anodes produce ions that kill Legionellae bacterial in the water • Ions also kill bacteria in the biofilm

40. Copper/Silver Ionization Negatives • Expensive • Constant monitoring of ion levels • Sacrificial anodes need regular replacement • Ion levels can become toxic if they accumulate • Professionally qualified personnel required

41. Questions?