TUBERCULOSIS IN AUSTRALIA, 1989-1992 - BACTERIOLOGICALLY CONFIRMED CASES AND DRUG-RESISTANCE

Objective: To collate statistics, including drug susceptibility, of pa tients with bacteriologically confirmed tuberculosis in Australia duri ng 1989-1992. Design: Collaborative project among the five Australian mycobacterial reference laboratories. Study population: 2509 Australia n residents with bacteriologically confirmed tuberculosis. Outcome mea sures: Patient and specimen data, and drug susceptibility results reco rded for isolates of Mycobacterium tuberculosis and Mycobacterium bovi s. Results: The annual incidence during 1989-1992 was about 3.6 per 10 0 000. 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 pu lmonary 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 is olates were resistant to isoniazid and rifampicin in combination. Conc lusions: By international standards, Australia remains a ''low-inciden ce'' country for tuberculosis, with a static annual incidence. Multipl e drug resistance is uncommon and most patients should respond to the standard four-drug regimen. Nevertheless, because clinical data confir m that the pool of infected persons is being supplemented through immi gration, and that certain population subgroups have high rates of dise ase, it is essential that Australia maintain effective control program s.