Facilitator notes: Legionnaires’ disease: Risk assessment, outbreak investigation and control Session 5, Activity 2: Analysis and Interpretation of Laboratory Investigations ECDC, 2012

Scenario A single case in an elderly 78 year old female who developed LD 5 weeks after admission with a cerebrovascular accident, to high dependency ward Ward S (Bay 5) in Hospital H. There has been five other cases reported to the surveillance team with potential links to Hospital H.

Background case summary Six cases had contacts with local hospitals within the incubation period. Two cases - Strong association with Hospital H No clinical sample. Both used assisted baths. L. pneumophila found in water samples during routine checks. One case - visited hospital H Other risk factors identified. Two cases - visited hospital Other risk factors. One case - visited a different hospital.

Background: Hospital water system Risk assessment - out of date. No schematic of the water system. There didn’t appear to be a regular scheme of descale, clean and disinfection of outlets, shower heads and flexible shower hoses. No regular regime of temperature monitoring. Deadlegs around the water system. Poor documentation of issues (e.g. poor flow of water) and no follow up of actions. Highlights: Need to audit usage of assisted baths. Introduce flushing of infrequently used outlets. Survey wards for infrequently used outlets – dealegs. Up to date schematic to identify deadlegs/blindends. Regular maintenance is required to remove scale and scum which can encourage bacterial /biofilm growth. Temperature monitoring to ensure there is temperature control throughout the system. Documentation is necessary to enable audit of the work that is required and follow up to ensure the remedial work is completed.

Legionella results from environmental samples 1 Ward Area Sampled Temp. Count cfu L-1 Result RS ward WHB Hot tap Sluice 1 58.7 Not Detected WHB Cold Tap Sluice 1 14.5 Arjo Bath tap 27 54000 L.pneumophila sg1 Benidorm ST42 Arjo Bath cleaning shower 160 Shower Bay 5 16000 WHB Hot tap Sluice 2 57.2 WHB Cold Tap Sluice 2 14 Shower ensuite side room >10000 Ken ward WHB Hot mixer post flush Sluice 61.8 WHB Cold tap post flush 18.3 KA1 WHB 32095 Hot tap post flush sluice 55.8 KA2 WHB 32095 cold tap post flush sluice 17.6 KD2 WHB sluice cold tap post flush 14.8 CM1 WHB sluice Hot tap post flush 31.4

Legionella results from environmental samples 2 Ward Area Sampled Temp. Count cfu L-1 Result CM2 WHB sluice cold tap post flush 15.8 Not Detected WHB sluice Hot tap post flush 37.3 CM3 15.1 ITU WHB S/mix cold post flush 14.6 560 L.pneumophila sg1 Benidorm ST42 Outpatients WHB Main reception ladies toilet Hot pre 38.8 600 RS ward Female toilet Bay 3 hot 37.7 Side room 3 cold 28 3100 L.pneumophila sg1 Benidorm Side room 3 hot 42 900 OPD Area A Visitors toilet cold 17 Visitors toilet hot 48.5 OPD ECG room 1 cold 18 hot 36.7 280 Area D Sluice cold 26.3 Sluice hot 50.4 These are the results from the initial environmental sampling immediately after cases who had strong association with Hospital H. The assisted bath is particularly colonised and the temperature of the water sample from the bath tap is ideal breeding ground for bacterial growth. Some of the hot tap temperature is not reaching the target minimum of 50. Need to ensure that there is a good flushing regime, whilst the HWS is being investigated to rectify the hot water temperature. Some of the cold water is gaining heat- Look for insulation of pipework, look for plumbing faults. Highlight the importance of monitoring (sampling & temp profile) of conventional separate hot and cold taps. Because this is a very select number of outlets not representing the whole hospital, sampling strategy is to undertake wider sampling. For areas where high Legionella positives have been reported, need to undertake a root cause analysis for that outlet. Showerhead, hoses, TMV-dismantle, descale, clean & disinfect. Replace flexible hoses with solid copper pipe. Resample.

Task 1: 10mins If you are the proper officer (chairing the outbreak investigation in the area), list what you would do. The hospital is still open to the public, what emergency control measures would you initiate within Hospital H? What would be your advice based on the environmental microbiology results?

What can you conclude from the findings during the walk around?

Case summary: Six cases had contacts with local hospitals within the incubation period. Two hospital-acquired no clinical sample both used assisted baths. L. pneumophila found in water samples during routine checks. One case visited hospital no clinical sample. other risk factors Two cases visited hospital distinct strains from hospital strains. One case visited a different hospital distinct strain.

Task 2: 5mins What conclusion can you make from this? Was the hospital the source of the Legionnaires’ disease cases? Why? (5mins)

Assisted (Freedom) baths

Facilitator notes: Acknowledgements The creation of this training material was commissioned in 2010 by ECDC to Health Protection Agency (UK) and the University of Chester (UK) with the direct involvement of Louise Brown, Janice Gidman, Emma Gilgunn-Jones, Ian Hall (on behalf of the ECDC Legionnaires Disease Outbreak Toolbox Development Group), Tim Harrison, Rob Johnston, Carol Joseph, Sandra Lai, John Lee, Falguni Naik, Nick Phin, Michelle Rivett, and Susanne Surman-Lee. The revision and update of this training material was commissioned in 2017 by ECDC to Transmissible (NL) with the direct involvement of Arnold Bosman and Kassiani Mellou.