Tuberculosis in Australia: bacteriologically confirmed cases and drug resistance, 2007. A report of the Australian Mycobacterium Reference Laboratory Network.

The Australian Mycobacterium Reference Laboratory Network collects and analyses laboratory data on new cases of disease caused by the Mycobacterium tuberculosis complex. In 2007, a total of 872 cases were identified by bacteriology; an annual reporting rate of 4.1 cases per 100,000 population. Isolates were identified as M. tuberculosis (n=867), M. africanum (n=4) and M. bovis (n=1). Fifteen children aged under 10 years had bacteriologically-confirmed tuberculosis. Results of in vitro drug susceptibility testing were available for 871 of 872 isolates for isoniazid (H), rifampicin (R), ethambutol (E), and pyrazinamide (Z). A total of 98 (11.3%) isolates of M. tuberculosis were resistant to at least one of these anti-tuberculosis agents. Resistance to at least H and R (defined as multi-drug resistance, MDR) was detected in 24 (2.8%) isolates, all from overseas-born patients; 17 were from the respiratory tract (sputum n=16, endotracheal aspirate n=1). Thirteen patients with MDR-TB were from the Papua New Guinea-Torres Strait Islands zone. Of the 98 M. tuberculosis isolates resistant to at least one of the standard drugs, 54 (55.1%) were from new cases, 9 (9.2%) from previously treated cases, and no information was available on the remaining 35 cases. Seven were Australian-born, 90 were overseas- born, and the country of birth of 1 was unknown. Of the 90 overseas-born persons with drug resistant disease, 66 (73.3%) were from 5 countries: India (n=16); Papua New Guinea (n=15); the Philippines (n=12); Vietnam (n=12); and China (n=11). No XDR-TB was detected in 2007.