Genomic sequencing identifies tuberculosis cluster in inner-city Sydney boarding house, Australia, 2022

Authors

  • Eunice Stiboy South Eastern Sydney Public Health Unit, New South Wales Health, Sydney, New South Wales, Australia; National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australian Capital Territory, Australia
  • Standish Rigava St Vincent's Health Network Sydney, Sydney, New South Wales, Australia
  • Anthea Katelaris South Eastern Sydney Public Health Unit, New South Wales Health, Sydney, New South Wales, Australia
  • Vicky Sheppeard South Eastern Sydney Public Health Unit, New South Wales Health, Sydney, New South Wales, Australia; School of Public Health, University of Sydney, Sydney, New South Wales, Australia
  • Anna Glynn-Robinson National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australian Capital Territory, Australia
  • Yasmeen Al-Hindawi St Vincent's Health Network Sydney, Sydney, New South Wales, Australia
  • Hazel Goldberg Consultant in Respiratory and Tuberculosis Medicine, Prince of Wales Hospital, Sydney, New South Wales, Australia; Sydney Eye Hospital and Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
  • Kerrie Shaw South Eastern Sydney Local Health District, New South Wales Health, Sydney, New South Wales, Australia
  • Vitali Sintchenko New South Wales Mycobacterium Reference Laboratory, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead, New South Wales, Australia; Sydney Infectious Diseases Institute and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
  • Elena Martinez New South Wales Mycobacterium Reference Laboratory, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead, New South Wales, Australia
  • Taryn Crighton New South Wales Mycobacterium Reference Laboratory, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead, New South Wales, Australia
  • Ellen Donnan New South Wales Tuberculosis Program, Communicable Diseases Branch, Health Protection New South Wales, Sydney, New South Wales, Australia
  • Anthony Byrne St Vincent's Health Network Sydney, Sydney, New South Wales, Australia; University of New South Wales, Sydney, New South Wales, Australia

DOI:

https://doi.org/10.5365/wpsar.2025.16.4.1153

Keywords:

Mycobacterium tuberculosis, outbreak, whole genome sequencing, community transmission, low incidence country

Abstract

Objective: In 2022, the New South Wales TB Program was notified of genomically clustered Mycobacterium tuberculosis isolates from two smear-positive tuberculosis (TB) patients diagnosed 3 months apart. Secondary investigations found they resided in the same Sydney boarding house. The objective of this study was to investigate this cluster and conduct active case finding among contacts.

Methods: We conducted a site visit to understand transmission risk, reviewed patient histories, performed a risk assessment and conducted on-site TB contact screening, including interferon-gamma release assay testing. Long-term residents were also screened via chest X-ray. Past residents were referred to local TB services.

Results: Four residents with TB disease were identified, three of whom were genomically linked to the cluster. The exposure period in the boarding house was determined to be from January 2021 to September 2022. All residents and staff were considered contacts requiring screening. Of the 91 contacts identified, 37 (41%) completed screening, including 20 (22%) who attended the on-site clinic. Among those screened, one resident with TB disease (patient 4) and three residents and one staff member with TB infection were identified.

Discussion: This cluster highlights the role of genomic sequencing in detecting TB transmission. The first three patients were infectious for prolonged periods before diagnosis, likely facilitating transmission in communal areas. In multidwelling buildings with TB exposures, contact screening of all residents may be required when prolonged exposures are found. Strategies to increase screening completion should be further explored.

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Published

03-12-2025

How to Cite

1.
Stiboy E, Rigava S, Katelaris A, Sheppeard V, Glynn-Robinson A, Al-Hindawi Y, Goldberg H, Shaw K, Sintchenko V, Martinez E, Crighton T, Donnan E, Byrne A. Genomic sequencing identifies tuberculosis cluster in inner-city Sydney boarding house, Australia, 2022. Western Pac Surveill Response J [Internet]. 2025 Dec. 3 [cited 2025 Dec. 25];16(4). Available from: https://ojs.wpro.who.int/ojs/index.php/wpsar/article/view/1153

Issue

Vol. 16 No. 4 (2025): October – December

Section

Original Research

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