2. ARPHS agrees that there should be clear guidelines and risk management plans for Legionella control in these settings.

Transcription

1 Auckland Regional Public Health Service Cornwall Complex Floor 2, Building 15 Greenlane Clinical Centre Private Bag Symonds Street Auckland 1150 New Zealand Telephone: Facsimile: July 2015 Submission on the Guidelines for Legionella Control; in the operation and maintenance of drinking water distribution systems in health and aged care facilities. 1. Thank you for the opportunity for the Auckland Regional Public Health Service (ARPHS) to provide advice and input into the Guidelines for Legionella Control: in the operation and maintenance of drinking water distribution systems in health and aged care facilities. 2. ARPHS agrees that there should be clear guidelines and risk management plans for Legionella control in these settings. 3. We are supportive of the intent of the document, to provide health and aged care facility managers with a step-wise guide on how to manage Legionella risk within their facilities. 4. We have recommended a number of amendments to the document. This information is outlined in detail in Appendix 1. For ease of reference, the page number and relevant section of the document have been listed, with the corresponding comments listed below in bullet point format. Please note our comments are drawn from our knowledge and experience in dealing with Legionella risks in the New Zealand context. 5. The following submission represents the views of the Auckland Regional Public Health Service and does not necessarily reflect the views of the three District Health Boards it serves. information on ARPHS. 6. The primary contact point for this submission is: Andrew Phillipps Policy Analyst Environmental Health Auckland Regional Public Health Service Private Bag Please refer to Appendix 2 for more

2 Symonds Street Auckland ext Once again, thank you for this opportunity to submit on this issue. We would be happy to supply further information. Yours sincerely Jane McEntee General Manager Auckland Regional Public Health Simon Baker Medical Officer of Health Auckland Regional Public Health

3 Appendix 1 ARPHS feedback and recommendations Page 3 Under subheading Why Legionella is a particular concern We recommend changing the sentence which states healthy individuals are not prone to Legionella infection to healthy individuals may be prone to infection, though most will not develop an illness, or develop Pontiac Fever rather than Legionnaires disease. Page 7 - Water system risk vs. health risk We recognise the document states that the guidelines only apply to water systems in health and aged care facilities. Nonetheless, we consider the formulation of this document provides a good opportunity to inform facility managers of other possible Legionella sources within the facility e.g. the risk from L. longbeachae, and other Legionella species commonly found in soil, which can be associated with gardens, and pot plants, which are often present in hospitals and aged-care facilities. Page Plumbing system Suggest including ring mains as a form of water storage, equivalent to a hot water tank. Page 11 Pipework that allows heat transfer State that the ambient air temperature may well be >20 degrees Celsius, particularly in the summer months, and this will affect cold water pipes that should ideally be <20 degrees Celsius. Page 12 Age or condition of pipes Include consideration of the possible bactericidal benefits of copper pipes as opposed to other materials, and cross-relate this to copper/silver ionisation systems. Page 14 Respiratory therapy equipment Include the statement unless sterile diluent is used after the sentence about respiratory therapy equipment.

4 Page 16 Plumbing (design) controls State that the recommended hot water storage temperature in New Zealand is 60 degrees Celsius, which is not the expected delivery temperature of the water at the outlet. Also, we suggest specifying an appropriate maximum distance for outlets from Thermostatic Mixing Valves (TMV) in order to avoid replication of Legionella bacteria downstream. Page 17 Plumbing (commissioning) controls Add the desired contact time and concentration level of chlorine when conducting pre-commissioning chlorination. Add in some text on draining and isolating the pipework, to prevent dead legs, when de-commissioning portions of plumbing systems. Define the test microbial counts, and if this is also related to the heterotrophic plate count (HPC) for micro-organisms. Consider if the proposed control level of >10cfu/ml for positive Legionella cultures is appropriate, as this is the same as 10,000 cfu/l - which is a high risk, and is more like derived from the cooling tower standards of AS/NZS We suggest that the ISO11731 standard is the recognised method for detecting Legionella bacteria in potable water systems. The AS/NZS 3896 standard is a method for determining the levels of Legionella bacteria in wet cooling tower water systems. The AS/NZS 3896 standard (or equivalent) is not suitable for detecting low levels of Legionella bacteria in potable water systems, primarily because the lower limit of detection is 10,000 cfu/l. Page 17 - Plumbing (operational infrastructure) controls It has been suggested that 2 mg/l (2ppm) of chlorine is a level at which hospital water systems could be disinfected for Legionella control. Whatever chlorine level is determined to be appropriate, we would wish to see references to justify the recommendation. Page 19 Table 1 (Overview of systematic treatments) Specify the following in Table 1: - Heat Disinfection to include ring mains under the heading description. - Chlorine-based biocides to include adequate mixing and contact period under the heading weaknesses. - Chlorine-based biocides The concentration and contact time is not mentioned for chlorine-based biocides. If the standard used for

5 drinking water is considered 0.2 mg/l, then Legionella bacteria will be inhibited from replication, but not eliminated. The 2 mg/l mentioned above would make water unpalatable. We therefore query whether the guidelines are suggesting augmenting the chlorine levels for the hot/warm water systems only, in which case, chlorine is known to be dissipated by heat. - Copper-silver ionisation to include residual effect under the heading strengths. - Copper-silver ionisation to include under the heading weaknesses : 1. temptation to lower the heated water temperature; 2. dependent upon overseas equipment suppliers. Page Regular maintenance Regarding the sentence, Typical maintenance regimes are based on system analysis and risk assessment. They include: - Add (for the first two bullet points) the word vessels after the wording water storages. - The cleaning system components (fifth bullet point) does not specify how often or frequently the cleaning should occur. - Add rotational changing, sterilisation and replacement of shower hoses as a new bullet point. Page 22 Monitoring Under the sentence, The locations and frequency of water sampling should be based on factors, amend the first bullet point by adding the word visitors. For example, hot water systems and their components might cause residents, patients, visitors, or workers to Page 23 Operational monitoring Page 23 lists details of what should be included in the risk management plan when considering operational monitoring. In regard to the last bullet point - corrective action to be taken if the parameter is not within the specified operational limit - there is no mention of who determines/defines the specified operational limit.

6 Page 24 Table 3: Examples of risks, monitoring and controls for Legionella management in a health or aged care facility The desired chlorine residual is 0.2 mg/l in the Drinking Water Standards for New Zealand, and not <0.5 mg/l. We note <0.5 mg/l has been referenced twice in this table. Regarding the risk of stagnation of water in the plumbing system, the critical limit is listed as outlet unused for more than 7 days. This is inconsistent with what is stated earlier in the document at the top of page 21, which states outlets used less frequently should be flushed for 5 minutes every 5 days to avoid stagnation. Water temperature to be <50 o C what is the justification for stating <50 degrees Celsius? We aim for 55 degrees Celsius in Auckland as custom and practice following advice from the Institute of Environmental Science and Research (ESR). Page 25 Verification monitoring The document states that analytical results of samples taken as part of verification monitoring are often obtained more than 24 hours after the sample is taken. In our experience, Legionella test results are more likely to take two weeks to obtain. Details of verification monitoring documented in a facility s risk management plan should include the method of testing by the accredited laboratory that performed the analysis. Therefore, amend the fourth bullet point to read, the accredited laboratory that performs the analysis, and the method of testing. The last paragraph on page 25 notes that analysis for culturable Legionella is generally reported in terms of the numbers of colonies. We consider the volume should be included when detecting relative numbers of Legionella colonies i.e. x numbers per unit volume. Page 26 Table 4: Microbiological testing options Culture methods under the heading strengths it states that the AS 3896 and AS 4276 in Australia are the currently approved testing methods. We seek confirmation as to whether this is the same approved testing method used by ESR. Please refer to comments above about appropriate testing method. Immuno-agglutination (serotyping) under the heading description, it is unclear whether this technology tests Legionella colonies against antibodies specific for L. pneumophila serogroups only.

7 Immuno-agglutination (serotyping) under the heading weaknesses, consider adding the following bullet point, needs a clinical sample of choice. Page 27 verification monitoring At the top of page 27 the steps for a typical verification monitoring program are outlined. Steps 2 and 3 both refer to collecting a >250-mL sample. However, ARPHS protocol (in line with ESR advice) is to use a 1 L sample. Figure 2 should be amended to include L. species i.e. all types of Legionella rather than specifically stating Legionella (pneumophila and total) under cold outlet. Amend the second paragraph to include the word sample before the wording steps 1 and 2. Page Number of samples and frequency of sampling Mention is made of a 1 hour Legionella test under which could revolutionise monitoring if sufficiently sensitive i.e. detection limit 100cfu/L. We welcome the development and use of such field-testing technologies if it allows for more rapid intervention. Further explanation of these technologies would be beneficial. Page 29 Table 5: Examples of risks, monitoring and controls for Legionella management in a health or aged care facility The first monitoring test in Table 5 provides a general indication of system quality. We consider the guideline document should explain how the results from this test are to be interpreted, and in particular, how the results relate to the proposed sensitivity (critical limit) established for the Legionella verification test. We believe the insertion of an explanatory note within the table may benefit users. Also, in light of our comment regarding the sensitivity of the Legionella verification test, we seek confirmation that a heterotrophic plate count >500 cfu/ml is an appropriate threshold. The critical limit/verification for the second identified risk is too high, since >10 cfu/ml is equivalent to 10,000 cfu of Legionella bacteria per litre. We propose 100 cfu/l. In reference to the last bullet point, under the heading Example control measures, hyperchlorination as a sanitation option is unrealistic for a live system.

8 Page 30 Responding to detections or cases Refer to our previous comment above about how heterotrophic plate counts >500 cfu/ml may be too high for the critical limit. The first sentence of paragraph 2 states, Where Legionella is detected within the facility drinking water system It is unclear whether this statement is referring only to the cold water system, or includes the hot water system. Again, with reference to paragraph 2 where it states, the entire potable water network, the document should clarify whether potable water network means the cold and hot water systems, or just the cold water system. We suggest rewording the recommendation at the end of paragraph 3 to make it clear that the disinfection is applied to both hot and cold water systems, or state otherwise. Pages 30/ Corrective measures The pasteurisation method outlined in the document may be unrealistic in practice. We note the comment that many facilities do not have sufficient hot water storage capacity for efficient pasteurisation, and therefore the option to employ this method is limited. Regarding the hyperchlorination corrective measure, we note the following: mg/l of chlorine may well damage metal plumbing fixtures, hence thermal purging is easier and recommended. - This method is only effective with a small facility or a facility that can be evacuated. It is labour intensive and unrealistic for a live facility. - A chemical clean of the system using a highly alkaline detergent solution before hyperchlorination is again unrealistic for a live system. Cleaning of fittings replacement with cleaned units on a rotational basis is more feasible and cost effective. Page Response to suspected case of Legionnaires disease Amend the first sentence to read, Where a hospital- or aged care facilityacquired Legionnaires disease case is suspected or confirmed The reference to potable water network in the first sentence under heading 4.2 needs to be defined i.e. hot and cold system, or the cold water system only. We disagree with the following statement:

9 Once samples have been collected and the extent of contamination has been confirmed, you should disinfect the affected parts of the potable water network. Where a Legionnaires disease case is suspected or confirmed, we consider a more precautionary approach should be adopted, and corrective actions should be undertaken immediately, as more cases could occur while the Legionella cultures are being incubated. Page What to do if the problem persists It is ARPHS expectation that public health units (PHUs) investigate Legionella cases and support hospital colleagues around nosocomial cases. However, Infection Control is responsible for ongoing hospital Legionella control precautions. On page 32 under the heading what to do if the problem persists, the document states that aged care facilities can contact their local health department for advice on measures to address the risks. We seek clarification on this matter - is it intended that hospitals and aged-care facilities approach PHUs for Legionella control advice? If so, will the Ministry be conducting training for public health unit staff, and providing additional resourcing for this extra work? We are uncertain of the term prolonged dry washing we assume this to mean flannel washing, or a bed bath? To avoid confusion we suggest adding the definition to the abbreviations and definitions section of the document.

10 Appendix 2 - Auckland Regional Public Health Service Auckland Regional Public Health Service (ARPHS) provides public health services for the three district health boards (DHBs) in the Auckland region (Auckland, Counties Manukau and Waitemata District Health Boards). ARPHS has a statutory obligation under the New Zealand Public Health and Disability Act 2000 to improve, promote and protect the health of people and communities in the Auckland region. The Medical Officer of Health has an enforcement and regulatory role under the Health Act 1956 and other legislative designations to protect the health of the community. ARPHS primary role is to improve population health. It actively seeks to influence any initiatives or proposals that may affect population health in the Auckland region to maximise their positive impact and minimise possible negative effects on population health. The Auckland region faces a number of public health challenges through changing demographics, increasingly diverse communities, increasing incidence of lifestylerelated health conditions such as obesity and type 2 diabetes, infrastructure requirements, the balancing of transport needs, and the reconciliation of urban design and urban intensification issues.