Legionella Risk Management

Transcription

1 1 Legionella Risk Management Legionella Biology Hazards Guidelines HACCP

2 Dangers to my people deaths from recognized causes Bacterial agents in food 3,000 per year FDA costs $2.4 billion per year Fires in ,640 Workplace in ,547 Businesses spend $35 billion annually to comply with federal workplace safety standards Legionnaires Disease OSHA Technical Manual: Approximately 1,000 cases are reported annually to the CDC, but it is estimated that over 25,000 cases of the illness occur each year and cause more than 4,000 deaths. Cases reported annually increased 217%, from 1,110 in 2000 to 3,522 in 2009.

3 Dangers to my organization Bad publicity with damage to company and brand image Accidents and incidents with associated injuries and deaths Litigation Legal costs Employee dissatisfaction and demotivation The Risks: Public Health Risk Public Image and Business Risk Regulatory Risk Legal Risk

4 Legionella bacteria in Hospital water systems Hospitals are ideal locations for transmission of LD Large numbers of at risk people Plumbing system usually old & complex Water temperatures often reduced to prevent scalding Usually limited budget for monitoring water and biocide Rx Fields et al Clin Microbiol Rev, July 2002 There are no big buildings without legionella. There are only big buildings that have not been examined properly Vladimir Drasar Seek and ye shall find.

5 5 What is Legionellosis? It is the condition of being infected by Legionella Inhaled as an aerosol or water mist (typically <5-10 micrometers) Drinking contaminated water does NOT cause legionellosis But aspirating contaminated water or ice chips has caused disease It is not contagious Pontiac Fever (Humidifier Fever) An acute, febrile, self-limiting illness lasting up to five days Characterized by fever, fatigue, muscle pain Illness is caused by several Legionella spp. Legionnaires Disease (LD, legionellosis) A severe respiratory pneumonia treatable with antibiotics Characterized by malaise, anorexia, myalgia, headache, cough, fever 90% of cases are caused by L. pneumophilia SG1 Other species have been linked Legionella in water Transmission Inhalation, aspiration Susceptible host - micdadei, longbeachae, dumoffii, bozmanii

6 6 Who is at risk? Risk Factors years Elderly Existing respiratory disease years Smokers Immunocompromised CDC: Summary of Notifiable Diseases United States 87% of all reported cases were age >40 years Men are twice as likely as women to be afflicted Children under 15 years rarely are afflicted Emerging evidence of pediatric legionellosis (Neonates)

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9 How? 9 water mists Using showers Aspirating water Water features Using spas Washing Cooling Towers

10 Legionellosis - Public Health Significance 10 Estimated to cause 18,000 hospitalizations in the US each year 1 Likely incidence is much higher due to under reporting, under diagnosis CDC estimated that only 10% are diagnosed among hospital patients 95% of people infected develop Pontiac fever and may not seek care The incident rate may be at least 5X higher Fatality rates can approach 25% or higher Steady increase in US hospitalizations each year 2 4,000 deaths in the US each year 3 Most cases of disease are sporadic (>90%) HEALTHCARE 23% HOTELS 21% OTHER 56% (1) US Centers for Disease Control and Prevention (2) US CDC Reportable Cases of Notifiable Diseases (3) US Occupational Health and Safety Administration

11 11 Legionellosis can cause long-term debilitating health effects Healthy Chest X-rays of a normal healthy individual (left) and a legionellosis patient on admission, day 4, postinfection 1-yr and 7-yrs. Long-term effects can be seen in the post-infection radiographic images. A follow-up study of 122 survivors of an outbreak in the Netherland s found 75% showed fatigue 66% showed neurologic symptoms 15% exhibited post-traumatic stress Lettinga et. al. (2001) Legionnaires Disease at a Dutch Flower Show: Prognostic Factors and Impact of Therapy. Emerg Infect Dis December; 8(12): Admission Day 4 1 Year 7 Years Bartlett, C.L.R., Macrae, A.D., Macfarlane, J.T. (1986) Clinical aspects and diagnosis of Legionella, In: Legionella Infections, Chapter 3, pg 43, Fig. 3.1 (a to d). Edward Arnold Publishers, London, UK (ISBN ).

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13 13 Legionella spp. Fewer than half have been linked to disease There are 15 serogroups (SG) of L. pneumophilia Over 90% of community acquired cases in the US and Europe have been caused by Legionella pneumophilia SG1 Disease has also been linked to micdadei (2.8%) longbeachae (2.2%) dumoffii (1.5%) bozemannii (1.3%) Just remember Not all Legionella species cause disease L.adelaidensis L.anisa L.birminghamensis L.bozemanii * L.brunensis L.cherrii L.cincinnatiensis L.dumoffii * L.erythra L.fairfieldensis L.feeleii * L.geestiana L.glasguensis L.gormanii * L.gratiana L.hackeliae L.israelensis L.jamestowniensis L.jordanis * L.lansingensis L.londiniensis L.longbeachae * L.lytica L.maceachernii L.micdadei * L.moravica L.nautarum L.oakridgensis L.parisiensis * L.pneumophila * L.quateirensis L.quinlivanii L.rubrilucens L.sainthelensi L.santicrucis L.shakespearei L.spiritensis L.steigerwalti L.taurinensis L.tucsonensis L.wadsworthii L.waltersii L.worsleiensis Linked to Pontiac Fever in humidifiers and misters. Common blue-white species (autofluorescenece) * Species known to be associated with human infection

14 14 Legionella Natural habitat Lakes Ponds Soils Legionella is a rod-shaped bacteria Legionella can enter and proliferate in water systems from the air or through our city distribution systems. Grows at ph 5.1 to F (20-50 C) Rivers

15 15 Biofilm & Sediment Water systems become fouled with sediment and biofilm over time. These biofilms and sediments can support organisms which may be introduced into the system from breaks and leaks. Legionella are known to be present in all segments of community water supplies including treatment facilities. 1 Center for Biofilm Engineering, MSU, Bozeman, MT Organisms do not live in the water system individually, but together form an ecosystem, which is called biofilm. Bacteria within a biofilm may be up to 3000X more resistant to chlorine and up to 100X more resistant to monochloramine than bulk water bacteria. 2 (1) EPA-822-R-99-1, November Legionella: Human Health Criteria Document (p. III-13). (2) M W LeChevallier, C D Cawthon and R G Lee. (1988) Inactivation of biofilm bacteria. Appl. Environ. Microbiol. October 1988 vol. 54 no

16 What Goes On In Biofilm? 16

17 OTHER ORGANISMS Coliforms such as E. coli Pseudomonas Mycobacteria avium complex General Bacteria in Water Can be 500 cfu/ml Aerobic, slime formers Heterotrophic bacteria Anaerobic Giardia Cysts Cryptosporidium Acintobacter Campylobacter Salmonella Ameoba Amoebae

18 Building Water Systems 18 Water distribution is complex Water main breaks happen Large complex systems are more prone to Legionella growth than smaller systems Facility owners are responsible for water safety once the water enters the facility Secondary disinfection coupled with managing stagnant water conditions and water temperature is one of the most effective approaches for reducing risk

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20 20 Conditions that increase risk of causing harm Stagnation Function/Use Protozoa Defects Biofilms Deposits ph Wind Water Aerosol Sprays Release Pathogen Bugs Grow Proliferation Water Flow Temperature Biocides Risk of Causing Harm Susceptible People Breathe Population Smokers Gender Construction projects Pressure shocks Vacancies Dead-legs Water main breaks Immunocompromised Age

21 21 Utility Water - Design Intent Temperature vs. Proliferation Risk 212 / 100 Steam Humidification 176 / 80 Hot Water Boilers Disinfection Range F (70-80 C) Temperature, F / C 140 / / 40 Cooling Towers Slowly Die F (50-70 C) 131 F (55 C); die within 5-6 hours 140 F (60 C); die within 32 minutes 151 F (66 C); die within 2 minutes Growth Range F (20-50 C) F (35-46 C) optimum 68 / / 0 Spray Humidifiers HVAC Condensate Proliferation Risk Dormant <68 F (<20 C)

22 22 Cooling Towers Fans Piping Drift Eliminator Water Sprays Fill Pack Drift Eliminator Use the best technology Water Basin Water Sump

23 23 Do I have issues with deposits or scale?

24 Do I operate within design? 24

25 Do I operate systems near people or entry points? 25

26 26 Doesn t my cooling water treatment program address this? No, not necessarily. Water treatment alone will not address risk. Risk reduction requires expanding practical knowledge for operational performance goals to also reduce health-related risk due to legionellae. FROM Operational Performance TO INCLUDE Reduction of public healthrelated risk associated with legionellae Focused on System Efficiency Scale & Corrosion Control Biofouling Control The Microbial World Fouling Water Treatment Model Focused on Risk Management Plan Legionella Control & Monitoring Clean & Disinfect

27 27 Domestic Services - Design Intent Temperature vs. Proliferation Risk 212 / / 80 Disinfection Range F (70-80 C) Temperature, F / C 140 / / 40 Hot Water Storage Hot Water Services Spas & Bathing Showers Slowly Die F (50-70 C) 131 F (55 C); die within 5-6 hours 140 F (60 C); die within 32 minutes 151 F (66 C); die within 2 minutes Growth Range F (20-50 C) F (35-46 C) optimum 68 / / 0 Cold Water Services Cold Water Storage Mains Cold Water Proliferation Risk Do Not Grow Well F (20-25 C) Dormant <68 F (<20 C)

28 Domestic Water Services 28 Water Storage Heat Exchangers Point-of-use

29 Domestic Water Service Hazards 29

30 30 Stagnation & Temperature Problems 38 C (100 F) 52 C (125 F)

31 Standards & Guidelines 31 Local Guidelines Allegheny County, PA Maryland New York Texas Virginia

32 What is HACCP? 32 Hazard Analysis Critical Control Points Systematic approach Intent is to apply control measures Food safety for astronauts Reduce significant hazards to an acceptable level Chemical Biological Physical

33 7 HACCP Principles Conduct Hazard Analysis 33 Document Determine CCP Verification Plan Establish Limits Corrective Action Plan Monitoring Schedule

34 Three Essential Functions 34 Identify Inventory/Flow Diagrams/Hazard Assess Potential Hazard CP/CCP Set Goals Procedures Goals Frequency Standards Contingencies Process for Verification Process Validate Plan Adjustments Document

35 (1) Form a HACCP Team 35 The team who will oversee the plan and make key decisions Appoint a team leader who will oversee the plan and ensure it is followed HEALTHCARE Hosp., LTC, etc. Team Members Facilities director Administrator Infection control Health & Safety Environmental Services Medical director Engineering Quality INSTITUTIONAL Edu., Hotels, Casinos, etc. Team Members Facilities director Health & Safety Housekeeping Maintenance & Engineering Finance General Manager INDUSTRIAL F&B, Pharma, Mfg., etc. Team Members Plant manager Health & Safety Maintenance & Engineering Quality Finance

36 36 (2) Water system inventory & flow diagrams Domestic services (potable) Water heaters Water storage Points of Use (POU) - Sinks, showers, etc. Cooling towers Pools & Spas Decorative fountains Water filters Cross-connections Fire protection Swamp coolers Drinking water fountains & coolers Other water using devices Verify inventory and flow diagrams with a facility walk-through Irrigation Plumbing & distribution Ice machines Notes Photos Water Temp Chlorine

37 Utility Water Systems Domestic Services 37

38 (3) Hazard analysis 38 Biological Physical Chemical Proliferation Aerosolization Temperature Primary disxn Secondary disxn

39 (4) Define Critical Control Points 39 Hazard Analysis Use the process flow diagrams and walk through information Proliferation Aerosolization What is the potential hazard for each process? Control Points A hazard potential where aerosol risk, bacterial risk, or both may be significant is a CP. Control points are notable potential hazard points that require monitoring and implementation of risk reduction strategies to reduce risk. Critical Control Points A hazard potential that presents a significant risk is considered a CCP and is assigned a number. Significant risk Hazard control is being applied Hazard control could be applied Essential to eliminate a hazard or reduce it to an acceptable level.

40 Critical Control Points Team Decision 40 Critical Control Point Control Limit Control Monitoring Method Frequency of Monitoring Contingency

41 Example Hazard Analysis (Utility Water Systems) 41 (1) Process Unit Operation (E) Air Handling Units Heating, Ventilation, Cooling (F) Chilled Water Loop & Chillers Chilled water supply for AHU chill coils (G) Condensing Water Loop & Cooling Towers Condensing water cooling loop for chillers (H) Side Stream Device Side stream filter device. Applies to CT#1 only Aerosol Risk (2) Hazard Potential (3) CP Bacterial Risk (4) CCP (5) Risk Reduction Strategy LOW LOW Aerosol exposure risk is low Bacterial proliferation is low if chill coil face velocities do for condensate pans that not exceed design, and if drain properly, and where no air filters of proper wet humidification is used. efficiency for the application is installed and maintained properly. LOW Closed point in the system. HIGH Aerosol risk is high for cooling towers, which by design produce aerosols. LOW Closed point in the system. MODERATE Bacterial proliferation risk is moderate when temperatures rise above 77 F or during stagnant periods. HIGH Bacterial proliferation potential is high due to high potential for contaminants from the air and due to optimal operating water temperatures and ph that supports bacterial growth. HIGH Bacterial proliferation risk is high in filter devices. YES NO YES NO YES YES YES NO Maintain use of high efficiency air filters is necessary for the end use application. Maintain clean coils and condensate pans. Perform required maintenance and water treatment for optimum performance. CCP1 * Maintain an effective biocide program to ensure biological control. * Clean and disinfect systems according to best practice protocols during start up, shutdown, commissioning, after idle periods and as needed during operation. Maintain mechanical (e.g. drift eliminators) and operational elements of the system through regular inspection and review to ensure limited aerosol release within design. Maintain a water treatment program for scale and corrosion control Perform required maintenance (e.g., back-flushing) for optimum performance and to limit microbial growth.

42 42 (5) Define Monitoring & Control Limits for the CP and CCP s CONTROL MEASURES Control measures are evidence based industry best practices that have proven to be effective for reducing risk associated with Legionella. MONITORING TASKS Monitoring is necessary to verify the control measures work. MONITORING FREQUENCY Set a reasonable frequency for monitoring tasks. Reference industry guidelines. CRITICAL LIMITS Set critical control limits for each monitoring task. Establish goals to control within. CONTINGIENCY PLANS Define corrective action when critical limits are not met.

43 Example Verification Plan (Utility Water Systems) 43 In southern climates where systems operate year-round, off-line C&D may be necessary twice a year. OSHA Tech. Manual. (OTM) - Sec. III: Chapter VII: Legionnaires Disease. Cooling towers should be cleaned and disinfected at least twice a year. Normally this maintenance will be performed before initial start-up at the beginning of the cooling season and after shut-down in the fall. Systems with heavy biofouling or high levels of Legionella may require additional cleaning. Any system that has been out of service for an extended period should be cleaned and disinfected. New systems require cleaning and disinfecting because construction material residue can contribute to Legionella growth.

44 (6) Documentation, Verification, Validation 44 Documentation Defined requirements in the HACCP Plan Methods may include: Building automation system Preventive maintenance work orders Housekeeping work orders Vendor reports Paper or electronic logs TEAM MEETING MINUTES Verification Designate a responsible person to ensure that control measures, monitoring, and corrective action are being carried out. The responsible person must directly review the documentation and verify implementation. Validation The effectiveness of the HACCP plan must be validated. Is the plan being followed? Is the plan working as intended? Is there any new scientific evidence to validate selection of the CCP or control limits?

45 Validation Methods 45 Option A Cite studies that demonstrate reduced prevalence of Legionella as a result of implementing similar control measures. This method is passive as it does not provide direct evidence of control based on testing specific to the system. Option B Monitor cases of facility-acquired legionellosis. This method is essential for hospitals and LTC facilities. This method is not feasible for most other facilities such as hotels, casinos, institutional facilities, manufacturing, etc. Option C Test the water systems routinely for Legionella and evaluate effectiveness of the control measures based on criteria defined in the HACCP plan. This method provides direct evidence of control and can help facilities justify changing the CCP, the control limits, or the frequency of testing.

46 46 ASSESS ACT ANALYZE ADJUST Assess and develop a plan Act and implement the plan Hold team meetings to analyze, verify and validate Adjust the plan based on Verification and validation results New scientific findings New standards or guidelines

47 47 Legionella Risk Reduction Strategies Action Steps Utility Water Systems Domestic Services Other At Risk Water Systems

48 HACCP Plan Requirements: Cooling Tower 48 Strategy Purpose Reference System Operation Inspection & Maintenance Design & Siting Scale & Corrosion Control Biocide Control Clean & Disinfect (C&D) Legionella Monitoring Goal is to operate in a manner that keeps the system treated and limits stagnant conditions. Startup/Shutdown; Intermittent operation; New system startup Goal is to maintain mechanical design intent to limit aerosol release, to maintain balanced water flows and to eliminate dead zones. Be aware of design features (sumps, drift eliminators, location of tower) that can increase risk if not properly managed. A comprehensive scale and corrosion program is necessary to limit scale and corrosion formation to within specified critical limits. A comprehensive biocide program applied to within critical limits is necessary to maintain microbial control. Biocides must be applied in a manner that demonstrates control. Goal is to prevent accumulation of slimes and sludge which can allow microbial proliferation and increase Legionella risk. Twice annual C&D; Off-line and On-line Recommended to verify control of the hazard. * Typically recommended for investigative or post remedial verification purposes. Aerobic Bacteria Monitoring Monitoring is essential to verify biocide program is sufficient to control microbial growth. CTI ASHRAE 12, 188P CTI ASHRAE 12, 188P CTI OSHA ASHRAE 12, 188P CTI OSHA ASHRAE 12, 188P CTI ASHRAE 12, 188P CTI OSHA ASHRAE 12, 188P CTI OSHA ASHRAE 12 CTI OSHA*

49 HACCP Plan Requirements: Domestic Water Services 49 Strategy Purpose Reference New Construction/ Renovation New Systems, Startup/Shutdown Goal is to be aware of design features (cross connections, need for piping insulation, dead-legs, low flow zones, water hammer arrestors, etc.) or stagnant conditions that can increase risk if not properly managed. Goal is to define practice to manage the water system to limit stagnation, implement practices to flush systems after lengthy shutdown or interruption of water service, and requirements for clean and disinfection before commissioning new systems. ASHRAE 12, 188P OSHA ASHRAE 12, 188P System Maintenance Water Temperature Water Disinfection Emergency Disinfection Goal is to define practice (Clean and disinfect, flushing, repair, etc.) for system maintenance of hot and cold water tanks, ice machines, water filters, shower heads and hoses, faucets, etc. Water temperature recommendations for legionellae control are: Maintain water heater outlet temperatures at or above 140 F (60 C); Maintain the hot water temperature at coldest point in the water heater, the storage tank, or the distribution system at or above 124 F (51 C); Maintain the cold water temperature in any part of system at or below 77 F (25 C). Where water disinfection or treatment is performed, a defined program must be followed to assure it meets EPA requirements for potable water applications. Goal is to define practice to be followed if there are suspected legionellosis health problems associated with the use of potable water in a building system. ASHRAE 12, 188P ASHRAE 12, 188P OSHA ASHRAE 12, 188P OSHA ASHRAE 12, 188P OSHA Legionella Monitoring Recommended to verify control of the hazard. * Typically recommended for investigative or post remedial verification purposes. ASHRAE 12 OSHA*

50 50 What can I do to reduce risk? Be proactive and raise awareness Understand the biology Understand the systems and how water is used Understand best practices HACCP is a process not a book that sits on a shelf Team approach Assign a responsible person to keep the project on track Start with a simple water system inventory

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52 52 Questions and Discussion