Tuberculosis in Australia: bacteriologically confirmed cases and drug resistance, 2002: a report of the Australian Mycobacterium Reference Laboratory Network

Commun Dis Intell Q Rep. 2003;27(4):459-65.

Abstract

The Australian Mycobacterium Reference Laboratory Network collected and analysed laboratory data on new cases of disease caused by Mycobacterium tuberculosis complex in the year 2002. A total of 712 cases were identified by bacteriology, representing an annual reporting rate of 3.6 cases of laboratory-confirmed tuberculosis per 100,000 population. The most commonly encountered culture-positive specimens were sputum (n=325), lymph node (n=142) and bronchoscopy (n=100). Smears containing acid fast bacilli were present in sputum (53.2%), bronchoscopy (37.9%) and lymph node (21.2%). Eight children (male n=3, female n=5) under 10 years of age had bacteriologically-confirmed tuberculosis. A total of 55 isolates (7.7%) of M. tuberculosis were resistant to at least one of the standard anti-tuberculosis agents. Resistance to at least isoniazid and/or rifampicin was noted for 53 isolates (7.4%), with multidrug-resistance (MDRTB) observed in 12 (1.9%) isolates. Of the 12 MDRTB isolates, eight were from the respiratory tract and five were from smear positive specimens. Of the patients with drug resistant M. tuberculosis isolates, 51/55 (92.7%) were classified as having initial resistance, none had acquired resistance during treatment in Australia. The country of birth was known for 54 of 55 such patients; four were Australian-born, and 50 (90.9%) had migrated from a total of 17 countries. Nucleic acid amplification testing (NAAT) was performed on 139 (19.5%) of the 712 culture-positive specimens. Of smear positive respiratory specimens, 74/80 (92.5%) were NAAT positive. For smear negative respiratory specimens, 12/17 (70.6%) reported a NAAT positive result. Importantly, false-negative NAAT results were obtained from 1/16 and 5/64 of smear positive bronchoscopy and sputum specimens respectively.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antitubercular Agents / pharmacology*
  • Antitubercular Agents / therapeutic use
  • Australia / epidemiology
  • Bronchoscopy / methods
  • Child
  • Child, Preschool
  • Drug Resistance, Multiple, Bacterial*
  • False Negative Reactions
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Isoniazid / pharmacology
  • Isoniazid / therapeutic use
  • Male
  • Middle Aged
  • Mycobacterium tuberculosis / drug effects*
  • Predictive Value of Tests
  • Rifampin / pharmacology
  • Rifampin / therapeutic use
  • Sputum / microbiology
  • Tuberculosis / diagnosis*
  • Tuberculosis / drug therapy
  • Tuberculosis / epidemiology*
  • Tuberculosis / microbiology

Substances

  • Antitubercular Agents
  • Isoniazid
  • Rifampin