Tuberculosis in Australia: bacteriologically confirmed cases and drug resistance, 2004: a report of the Australian Mycobacterium Reference Laboratory Network

The Australian Mycobacterium Reference Laboratory Network collected and analysed laboratory data on new cases of disease caused by Mycobacterium tuberculosis complex in the year 2004. A total of 787 cases were identified by bacteriology, representing an annual reporting rate of 3.9 cases per 100,000 population. Almost all isolates were identified as M. tuberculosis (n = 785), the remaining isolates being one each of Mycobacterium africanum and Mycobacterium canettii. Seven children under 10 years of age (female n = 5, male n = 2) had bacteriologically confirmed tuberculosis (gastric aspirate n = 4, lymph node n = 1, pleural n = 1, thigh wound n = 1). Results of in vitro drug susceptibility testing were available for all 787 isolates for isoniazid (H), rifampicin (R), ethambutol (E), and pyrazinamide (Z). A total of 71 (9.0%) isolates of M. tuberculosis were resistant to at least one of these anti-tuberculosis agents. Resistance to at least both H and R (defined as multidrug resistance) was detected in 12 (1.5%) isolates; 10 were from the respiratory tract (sputum n = 7, bronchoscopy n = 3). The country of birth was known for 68/71 (95.8%) cases with a drug resistant strain; eight were Australian, 60 were overseas born, and three were unknown. Of the 60 migrants with drug resistant disease, 37 (61.7%) were from three countries; Viet Nam (n = 20), China (n = 9) and India (n = 8).