Dr K Luden Legionella type bacteria in domestic

Dr. K. Luden Legionella type bacteria in domestic distribution systems (house installations) Dr. Katrin Luden Warschau Nov. 2008 1

Dr. K. Luden Legionella type bacteria Ø are fresh water bacteria (~ 50 species, all of them potentially pathogenic to humans) Ø grow best in warm water e. g. in warm drinking water supply, pools (filter), air condition-systems or cooling towers Ø hardly grow <20°C and die at >60°C Ø infections are transmitted by inhalation of aerosols rarely by aspiration (90 % of infections caused by L. pneumophila) Ø cause Pontiac-fever and legionaires disease

Dr. K. Luden Infections caused by Legionella Pontiac-fever acute self-limiting influenza-like infection without pneumonia Incubation time: 2 -3 days Cases ~800. 000 – 1. 5 billion / year (estimate of RKI) Legionaires disease Pneumonia (fever, chills, cough) sometimes fatal Incubation time: 2 -10 days Cases: ~ 6. 000 - 20. 000 / year (estimate of RKI) Fatal cases: ~ 1. 000 - 3. 000 / year (estimate of RKI)

Dr. K. Luden Drinking water directive 98/83/EC Legionella not mentioned but General obligations (Article 4): Water shall be clean if it: is free from micro-organisms which in numbers or concentrations, constitute a potential danger to human health Article 5 (3) Quality standards “A Member State shall set values for additional parameters not included in Annex I where the protection of human health within its national territory or part of it so requires. The values set should, as a minimum, satisfy the requirements of Article 4(1)(a). ”

Dr. K. Luden German Drinking water directive (DWD) § 18 Monitoring by public health authorities (1) Public health authorities supervise the water supply . . . from domestic distribution systems from which water is made available for the public, in particular in schools, kindergartens, hospitals, restaurants and other communal facilities, regarding the compliance to the requirements of the regulation by appropriate examinations.

Dr. K. Luden German Drinking water directive (DWD) Legionella mentioned twice: § 20 order of the public health authorities can order analysis of additional parameters considering the circumstances of the individiual case. . . e. g. Legionella. . . And Audit monitoring (Annex) Audit monitoring includes the investigation on Legionella in central drinking water warming systems as part of domestic distribution systems that supply water to the public.

Dr. K. Luden Rationale Due to the considerable potential danger to human health connected to Legionella in warm water domestic distribution systems water from those systems has to be monitored for Legionella in facilities supplying water to the public. BUT

Dr. K. Luden Questions Ø What is the aim of the monitoring? Detection of systemic contamination or acute risk assessment? Ø What parametric values are to be used for assessment of results? Ø Sampling: where, how many samples, how, when?

Dr. K. Luden Aim of monitoring Recommendations by NLGA (2006) and FEA (2007): detection of systemic contamination The purpose in Lower Saxony is to gather information on systemic contamination with comparable results due to harmonized sampling techniques and sample identification using a coding system. The laboratory method for detection of Legionella was covered as well because ISO 11731 was not translated into a DIN.

Dr. K. Luden Technical Standards DIN 1988 (1988): technical standard for drinking water installations VDI*-Guide 6023 (2006): hygiene-conscious planning, construction, operation and maintenance of drinking water heating systems DVGW** W 551 (2004): Drinking water heating and distribution system, technical measures for limiting growth of legionella; planning, establishment, operation and redevelopment of drinking water installations DVGW** W 553 (1998): Dimensioning of central warm water circulation systems * VDI: Society of German Engineers **DVGW: German Technical and Scientific Association for Gas and Water

Dr. K. Luden Recommendation of the Federal Environmental Agency (FEA) Categories of facilities that have to be monitored 1) Hospitals and nursing facilities (geriatric homes, nursing homes, baby-nursery) 2) Facilities for ambulant surgery, dialysis, rehabilitation. . . 3) Schools, Kindergarten 4) Hotels, youth hostels 5) Other training facilities, homes, holiday camps etc. 6) Sports facilities 7) Community accommodations

Dr. K. Luden Recommendation of the Federal Environmental Agency (FEA) In addition to W 551: Ø In Facilities of category 1 and 2 (Hospitals, nursing facilities) no orientating investigation but always extensive investigation Ø Additional sampling in units with high risk (e. g. intensive care units) Ø Facilities with many division ranks (Teilstränge) sampling has to be conducted in units were showers are used

Dr. K. Luden Parametric values No recommendation by authorities because: Ø Little or no data on the correlation between Legionella concentration in water and infection rates Ø Legionella are not normally distributed in water (biofilms, amoeba) ? Should a domestic warm water distribution system that is up to date not be free of Legionella? Detecting 500 CFU/100 ml one day can result in 5. 000 or 500. 000 the other day.

Dr. K. Luden W 551 Assessment of the results of a routine monitoring (orientating 1 x a year) Legionella Level of CFU/100 ml contamination measures Further investigation > 10. 000 extremely high Direct clearance Instantaneous measures (disinfection, prohibition of use) remediation necessary > 1. 000 High Follow up 1 week after disinfection or remediation Remediation depends Immediately on outcome of further investigation 100 Middle None Within 4 weeks < 100 Low/no None After 1 year

Dr. K. Luden Lower Saxony Technical survey and inspection of the distribution system always first (checklist provided with the recommendation) Negative results of Legionella samples are no proof of a technically correct system Sampling point Water body to be checked during monitoring 1 2 i 1 2 i Verteiler 1) L 1 Austritt Trinkwassererwärmer Zulauf 3) L 3 Rücklauf Zirkulationsleitung 2) LS 1 -LSi Steigstrang

Dr. K. Luden Sampling Specifications: L 1 sampling at maximum temperature, document sampling temperature LS run off exactly 1 liter of water, take sample, document sampling temperature, flush to maximum temperature, document temperature L 3 flush shortly to sample circulating water, document temperature Follow instructions of ISO 19458 purpose b.

Dr. K. Luden Sampling - ISO 19458 Detection of systemic contamination: purpose b Purpose Quality a In the main b As it reaches the tap c As consumed Remove attached Disinfect devices and inserts Yes flush Yes Yes Noa (miminal) No No No a flush shortly only to overcome influence of disinfection of the tap

Dr. K. Luden Sampling - ISO 19458 Risk assessment or case related investigation: purpose C Purpose Quality a In the main b As it reaches the tap c As consumed Remove attached Disinfect devices and inserts Yes flush Yes Yes Noa (miminal) No No No a flush shortly only to overcome influence of disinfection of the tap

Dr. K. Luden Detection method - ISO 11731 Water sample Direct plating Membrane filtration 0. 5 ml GVPC 20 ml GVPC 100 ml GVPC Incubation at 36 ± 2°C for 7 -10 days Subculture confirmation optional

Dr. K. Luden Detection method - ISO 11731 Range of measurement: 1) Plating of 2 x 0. 5 ml → < 100 to 40. 000 CFU/100 ml with a maximum of 200 colonies per plate in accordance with ISO 8199 2) Membrane filtration of 20 ml → < 5 to 500 CFU/100 ml with a maximum of 100 CFU/filter Total of < 5 to 40. 000 CFU/100 ml

Dr. K. Luden Results 2005 Legionella Samples Assessment by W 551 [n] total 2637 < 5 1873 No / low contamination 5 764 Low contamination > 10 644 Low contamination > 100 > 1. 000 > 100. 000 409 149 42 1 Middle mid term remediation High cont. short term remediation Extremely high cont. imediate action

Dr. K. Luden Consequences Ø Facilities with samples that show extremely high contamination with Legionella might be asked to take action immediately. Ø Operators of house installations with medium contamination are asked to provide a mid term remediation plan. Ø Advice is offered and sometimes facilities are closed e. g. showers at a public swimming pool as a safety measure to public health. Ø NO concrete action is ordered by the public health services. The responsibility for providing safe water lies with the operator of the house installation.

Dr. K. Luden Concluding remarks Ø Sampling and evaluation of Legionella detection in house installations has been harmonized in Lower Saxony. Ø Consulting of Public health services and operators of house installations contaminated by Legionella has become easier. Ø Sampling techniques fit the purpose of the monitoring. Ø If the recommended protocol is used and all temperatures are documented a first step towards finding the cause of the problem often is taken. Ø Although technical standards have been existing for more than 20 years facilities prevail that are not at the state of the art.