NSW Tuberculosis Surveillance Report 2024: Laboratory

​​​​​​​​​​​​​​​​On this page

  1. Method of diagnosis of tuberculosis cases in NSW, 2024
  2. Drug susceptibility of culture confirmed cases in NSW, 2024
  3. Culture positive tuberculosis cases in NSW linked by whole genome sequencing
  4. Outcome of epidemiological investigation into links to other cases in a whole genome sequenced cluster in NSW, 2024
  5. Type of epidemiological link for cases in a whole genome sequenced cluster with a confirmed or possible link to another case in NSW, 2024

M​ethod of diagnosis of tuberculosis cases in NSW, 2024

Most TB cases are diagnosed through laboratory findings, with 67% of cases having a positive TB culture and 12% of cases having a positive PCR (without a positive culture).

Drug​​​ susceptibility of culture confirmed cases in NSW, 2024

The majority of culture positive TB cases (91%) in NSW are fully sensitive to first line TB treatment. A small number of cases have either multi-drug resistance (MDR) (<1%) or pre-extensively drug resistance (Pre-XDR) (<1%).

Drug susceptibilityNumber of casesPercentage
Fully Sensitive to first line TB drugs316
91%
Monoresistance: Isoniazid16
5%
Monoresistance: Rifampicin3
<1%
Monoresistance: Ethambutol3
<1%
Monoresistance: Pyrazinamide0
0%
Resistant to 2 or more first line TB drugs (but not MDR)0
0%
MDR1​ (excluding pre-XDR and XDR)
3
<1%
Pre-XDR2​1<1%
XDR3​00%

Whole g​​enome sequencing (WGS) cluster analysis, NSW, 2024

Culture posi​tive cases found to be linked to another NSW case by WGS are classified as being in a cluster. Linked cases are within 12 single nucleotide polymorphisms (SNPs) of another case in the same cluster.


42 (12%)
Culture positive cases linked by WGS


37
WGS clusters
where new case was added

Outcom​​e of epidemiological investigation into links to other cases in a WGS cluster in NSW, 2024

The first case in the cluster is the index case. Epidemiological investigations found a confirmed or possible link for 81% of cases in WGS clusters in 2024. A confirmed link is when there is direct contact between two cases while the first case was infectious in both place and time. A possible link is when there are similarities in place and time but a direct link is not identified when the first case was infectious.

Epidemiological linkNumber of casesPercentage
Index case3
7%
​Confirmed link
22
52%​
Possible link
12
29%
No evidence of any links
2
5%
No plausible transmission within Australia43
7%

Ty​pe of epidemiological link for cases in a WGS cluster with a confirmed or possible link to another case in NSW, 2024

The most common type of link, when known, to another case in the cluster was household, family and close friend links (50% of cases), followed by community linked (35%). Community links can include sports, places of worship, other community groups or residence in the same geographical area​.


Type of link when possible/confirmedNumber of casesPercentage
Household, family, close friend17
50%
Community12
35%
Workplace
3
9%
​Educational facility
1​3%​
​Other
1​3%​

Notes

  1. MDR (multi-drug resistance): Resistance to at least isoniazid and rifampicin.
  2. Pre-XDR (pre-extensivel​y drug resistance): Resistance to at least isoniazid, rifampicin and also any fluroquinolone.
  3. XDR (extensively drug resistance): Resistance to at least isoniazid, rifampicin and any fluroquinolone and at least one additional Group A drug (levofloxacin, moxifloxacin, bedaquiline or linezolid).
  4. Case was not resident in Australia while earlier cases in the cluster were infectious.
  5. Data for this report was extracted from Notifiable Conditions Records for Epidemiology and Surveillance, NSW Ministry of Health on 11 June 2025. Additional data on whole genomic sequencing was extracted from TB WGS Epi REDCap Project Database.
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Current as at: Wednesday 13 August 2025
Contact page owner: Communicable Diseases