1. An Outbreak of Legionnaires’ Disease in NHS Greater Glasgow and Clyde and NHS Lanarkshire 2011 Dr Sonya Scott StR Public Health NHS GGC sonyascott@nhs.net

2. What I’ll Cover  Legionellosis  Timeline of Events  The Investigation  Lessons Learned and Recommendations

3. Legionellosis Legionellae bacteria 3 main requirements for growth and spread. Transmission by inhalation 2-10 day incubation 2 clinical presentations LD – 12% case fatality

4. Event Timeline (1) 7 April – possible nosocomial case notified to GGC. 16 April – a second case of community acquired LD notified to GGC. 26 April – third case of community acquired LD notified post-mortem to GGC.

5. Event Timeline (2) 5 May –Two further cases of community acquired LD notified to GGC. –PAG convened –HSE and EH begin process of inspecting ECS –Awareness raising partners, clinicians, public. 6-11 May –Two further cases notified to NHS GGC, one post- mortem and one to NHS LN –PAG becomes OCT

6. Event Timeline (3) 12-19 May –Two further cases, one post-mortem, notified NHS GGC and one to NHS LN –HPA asked to undertake temporal and spatial analysis of case data. –Inspection of all ECS complete 20 May - 30 June –Final case notified to NHS GGC –No epidemiological or microbiological link between cases found. No new cases as of 8 th July 2011 No common source identified.

7. The Investigation

8. Case Definitions Clinical/Radiological CAP + Greater Glasgow Association + Onset after 1 st March + Confirmed –+ isolate L.sp or seroconversion or urinary antigen or direct PCR full SBT. Probable –L.sp. Antigen sputum or lung or direct partial SBT or history shared setting with confirmed case Possible –Direct PCR L.sp. but no SBT or high single titre for L.sp.

9. Epidemiological Investigation Methods Three main parallel strands Standard Trawling questionnaires Geographical information system Modelling Work –Cluster analysis –Statistical calculation of release window –Kernel density analysis –Attack rate analysis

10. Results of Epidemiological Investigation (1) Eight cases GGC three LN 7 confirmed cases, 1 probable and 3 possible Median age 62y (range 34-84) 82% (9) male All hospitalised, with requiring ITU Smoking, Immunodeficiency common 36% case fatality.

11. Results of Epidemiological Investigation (2) Dates of onset 21 st March and 2 nd June Release window 14/3/11 – 28/4/11 2 clusters Commonality of movement centre Glasgow. No specific epidemiological link

12. Complexities of Epidemiological Picture Possibility of hospital acquired case Travel Histories Concomitant infections Occupational Histories False positive urinary antigen results!

13. The Human Microbiological Investigation 6 positive urinary antigen results 3 isolates –2 Knoxville, –1 France/Allentown 4 different SBTs Others –2 cases direct positive PCR no SBT –1 case direct positive PCR partial SBT –1 case Single high titre L.sp. Not assignable

14. The Environmental Investigation- Methods All domestic water systems sampled Occupational water systems sampled 57 ECS, across 23 companies inspected 23 ECS sampled –Sampling where clustering of movement or deficiencies

15. Results of Environmental Investigation Poor compliance with code of practice Significant failings – 4 companies All ECS samples negative for Legionella High bromine levels

16. Lessons and Recommendations (1) 1. There is a need to improve organisational compliance with code of practice for control of Legeionella risk R: HSE and COSLA to consider regular proactive inspection of regulated water systems to ensure compliance with ACOP. 2. It is difficult to determine the probability of common community source for a cluster of LD in the early stages of an investigation, without access to formal modelling techniques. R: There is a need to develop accessible technologies to assess cluster probability in an emerging situation.

17. Lessons and Recommendations (2) 3. Further guidance on the role of water sampling in the investigation of LD is required. R: To be considered in current revision of guidance by HPN, some interagency training may be required. 4. There is a need to review the role of diagnostic tests in the investigation of clusters and outbreaks of LD. R: To be considered in current revision of guidance by HPN.

18. Any Questions?