Investigation of a legionellosis outbreak in Sydney CBD - a brief report

Adam Capon; Toni Cains; Jenny Draper; Vitali Sintchenko; Mark Ferson; Vicky Sheppeard

doi:10.1016/j.anzjph.2023.100018

Investigation of a legionellosis outbreak in Sydney CBD - a brief report

Aust N Z J Public Health. 2023 Apr;47(2):100018. doi: 10.1016/j.anzjph.2023.100018. Epub 2023 Mar 23.

Authors

Adam Capon¹, Toni Cains², Jenny Draper³, Vitali Sintchenko⁴, Mark Ferson⁵, Vicky Sheppeard⁶

Affiliations

¹ South Eastern Sydney Local Health District, Public Health Unit, New South Wales, Australia; School of Public Health, The University of Sydney, New South Wales, Australia. Electronic address: adam.capon@health.nsw.gov.au.
² South Eastern Sydney Local Health District, Public Health Unit, New South Wales, Australia.
³ Centre for Infectious Diseases and Microbiology Laboratory Services, NSW Health Pathology - Institute of Clinical Pathology and Medical Research, New South Wales, Australia.
⁴ Centre for Infectious Diseases and Microbiology Laboratory Services, NSW Health Pathology - Institute of Clinical Pathology and Medical Research, New South Wales, Australia; School of Medicine, The University of Sydney, New South Wales, Australia.
⁵ South Eastern Sydney Local Health District, Public Health Unit, New South Wales, Australia; School of Population Health, University of New South Wales, New South Wales, Australia.
⁶ South Eastern Sydney Local Health District, Public Health Unit, New South Wales, Australia; School of Public Health, The University of Sydney, New South Wales, Australia.

PMID: 36965315
DOI: 10.1016/j.anzjph.2023.100018

Abstract

Objective: To identify and control a source of Legionella in Sydney CBD.

Methods: Clinical, epidemiological, environmental and genomic techniques were employed to identify cases and the source of Legionella.

Results: Eleven legionellosis cases were linked to Sydney CBD with a median age of 69 years. All were hospitalised and had risk factors for Legionella infection. Eight of 11 cases identified as male. Genomic analysis linked three cases to a contaminated cooling water source in Sydney CBD, with a further case infected with a similar strain to that found in Sydney CBD. Another case, although epidemiologically linked to Sydney CBD, was infected with a genomically different strain to that found in Sydney CBD. Six other cases had no viable sample for genomic analysis.

Conclusion/implications for public health: An outbreak of legionellosis is a serious public health threat that requires rapid investigation and environmental control. We were able to identify a source in Sydney CBD through the application of clinical, epidemiological, environmental and genomic techniques. Genomic analysis is a powerful tool that can be used to confirm the source location but requires close collaboration between clinicians, public health units and microbiologists to recover viable sputum cultures from cases diagnosed with legionellosis.

Keywords: environmental; genomic; legionellosis; legionnaires disease; outbreak.

MeSH terms

Aged
Disease Outbreaks
Humans
Legionella*
Legionellosis* / diagnosis
Legionellosis* / epidemiology
Male
Risk Factors
Water Pollution