Tuberculosis in Australia, 1989–1992: Bacteriologlcally confirmed cases and drug resistance

Abstract

Objective: To collate statistics, including drug susceptibility, of patients with bacteriologically confirmed tuberculosis in Australia during 1989–1992. Design: Collaborative project among the five Australian mycobacterial reference laboratories. Study population: 2509 Australian residents with bacteriologically confirmed tuberculosis. Outcome measures: Patient and specimen data, and drug susceptibility results recorded for isolates of Mycobacterium tuberculosis and Mycobacterium bovis. Results: The annual incidence during 1989–1992 was about 3.6 per 100000. The male‐to‐female ratio was 1.4:1 and about half the patients were under 50. Older men had high rates of disease. Lymphatic disease was significantly more common in females; the converse was true for pulmonary and pleural disease. Resistance to at least one of the common antituberculosis drugs was detected in 14.4% of isolates, and usually involved streptomycin (7.6%) and isoniazid (8.4%). Fewer than 1% of isolates were resistant to isoniazid and rifampicin in combination. Conclusions: By international standards, Australia remains a “low‐incidence” country for tuberculosis, with a static annual incidence. Multiple drug resistance is uncommon and most patients should respond to the standard four‐drug regimen. Nevertheless, because clinical data confirm that the pool of infected persons is being supplemented through immigration, and that certain population subgroups have high rates of disease, it is essential that Australia maintain effective control programs.

Bacteriological and Molecular Analysis of Rifampin-Resistant Mycobacterium tuberculosis Strains Isolated in Australia

“…In Australia, the incidence of TB is low by international standards. Since 1989, the annual incidence of laboratory-confirmed cases has remained between 3 and 4 cases per 100,000 population (2)(3)(4)(5), and the rate of drug resistance is less than 18%. The majority of the drug-resistant infections involved either streptomycin or isoniazid alone or in combination with other antibiotics excluding rifampin.…”

Management of tuberculosis in children

“…M. tuberculosis isolates resistant to a single drug are more common than multidrug resistant isolates, and must be considered when starting an anti‐tuberculosis treatment course 36,37 . If this situation is suspected, four drugs should be started pending susceptibility results.…”

Health care workers and tuberculosis

“…In Australia in 1995, only five (0.7%) strains resistant to both isoniazid and rifampicin were reported, but in 1996 this number increased to 15 (2%). 43 This, along with increases in both immigration and HIV infection in Australia and neighbouring countries, may cause the potential for Australia to experience a similar resurgence in T B as occurred in the United States.…”