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In 2006, the Australian Mycobacterium Reference Laboratory Network identified 905 bacteriologically confirmed cases of disease caused by members of the Mycobacterium tuberculosis complex. The annual reporting rate was 4.4 cases per 100,000 population. Of the 905 isolates, 903 were Mycobacterium tuberculosis and two were Mycobacterium bovis. Fourteen children aged under 10 years (male n = 5, female n = 9) had bacteriologically confirmed tuberculosis. A total of 100 (11.1%) isolates of M. tuberculosis were resistant to at least one first-line anti-tuberculosis agent. Resistance to at least H and R (defined as multi-drug resistant--MDR) was detected in 22 (2.4%) M. tuberculosis isolates. Of the 22 MDR-TB isolates, 17 were from the respiratory tract (sputum n = 11 bronchoscopy n = 5, nasogastric aspirate n = 1), three from lymph node, one from a sacral mass, and one sterile site fluid. Smear-positive specimens from the MDR-TB cases were found in sputum (n = 6), lymph node (n = 2), and one each of bronchoscopy and nasogastric aspirate specimens. The country of birth was known for all 100 cases with a drug-resistant isolate; 10 of whom were born in Australia. The 90 overseas-born cases with drug-resistant disease were from 27 countries. Two Australian-born cases had MDR-TB; one had worked extensively in the Philippines; the other was a contact of a known MDR-TB case. No cases of extensively drug-resistant TB (XDR-TB) were identified in 2006. However, an on-going review of laboratory data identified one case of XDR-TB in 2004.

The Australian Mycobacterium Reference Laboratory Network (AMRLN) collects and analyses laboratory data on new cases of disease caused by the Mycobacterium tuberculosis complex. In 2005, a total of 810 cases were identified by bacteriology; an annual reporting rate of 4.0 cases per 100,000 population. Isolates were identified as M. tuberculosis (n = 806), Mycobacterium africanum (n = 2) and Mycobacterium bovis (n = 2). Fifteen children aged under 10 years had bacteriologically-confirmed tuberculosis. Results of in vitro drug susceptibility testing were available for all 810 isolates for isoniazid (H), rifampicin (R), ethambutol (E), and pyrazinamide (Z). A total of 74 (9.1%) 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 12 (1.5%) isolates; nine were from the respiratory tract (sputum n = 8, bronchoscopy n = 1). Of the 74 M. tuberculosis isolates resistant to at least one of the standard drugs, 67 (90.5%) were from new cases, 6 from previously treated cases, and no information was available on the remaining case. Eight were Australian-born, 65 were overseas-born, and the country of birth of one was unknown. Of the 65 overseas-born persons with drug resistant disease, 41 (63.1%) were from 4 countries; Vietnam (n = 16), Papua New Guinea (n = 10), the Philippines (n = 9), and India (n = 6). A retrospective review of AMRLN data on isolates collected between 2000 and 2005 found that none of 70 MDR-TB isolates met the new definition for extensively drug resistant TB (XDR-TB, i.e. MDR-TB with additional resistance to quinolones and second-line injectable agents).

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).

The Australian Mycobacterium Reference Laboratory Network collected and analysed laboratory data on new cases of disease caused by Mycobacterium tuberculosis complex in the year 2003. A total of 784 cases were identified by bacteriology, representing an annual reporting rate of 3.9 cases of laboratory confirmed tuberculosis per 100,000 population. The most commonly encountered culture-positive specimens were sputum (n = 351), lymph node (n = 176) and from bronchoscopy (n = 97). Smears containing acid fast bacilli were present in sputum (53.0%), bronchoscopy (32.0%) and lymph node (23.3%). Five children (female n = 3, male n = 2) under 10 years of age had bacteriologically confirmed tuberculosis. Eighty isolates of M. tuberculosis and one of Mycobacterium africanum (10.3%) were resistant to at least one of the standard anti-tuberculosis agents. Mono-resistance to isoniazid, ethambutol, rifampicin, and pyrazinamide was detected in 45, three, two, and one isolates respectively. Multidrug-resistance (MDRTB) defined as resistance to both isoniazid and rifampcin was observed in seven (0.9%) isolates. Of the seven MDRTB isolates, six were from the respiratory tract and four were from smear positive specimens. Of the 81 patients with drug resistant isolates, 78 (96.3%) were classified as having initial resistance; two had acquired resistance and no information was available for one isolate; five were Australian-born; and 76 (93.8%) had migrated from a total of 30 countries.

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.

The Australian Mycobacterium Reference Laboratory Network collected and analysed laboratory data on new cases of disease caused by Mycobacterium tuberculosis complex in the year 2001. A total of 771 cases were identified, representing an annual reporting rate of 4.0 cases of laboratory-confirmed tuberculosis per 100,000 population. The predominant specimen type was sputum, (n=369) and a further 111 were collected at bronchoscopy. Smears were positive for 214 of 369 (58.0%) sputum and 42 of 111 (37.8%) bronchoscopy specimens respectively. Seven children (male n=5, female n=2) under 10 years of age had bacteriologically confirmed tuberculosis. A total of 69 isolates (8.9%), comprising 67 M. tuberculosis, one M. africanum, and one M. bovis, were resistant to at least one of the anti-tuberculosis agents. Excluding the M. bovis isolate, 61 of 64 (93.5%) were classified as having initial resistance, three had acquired resistance, and no data were available on the presence or absence of previous treatment for four patients. Resistance to at least isoniazid and/or rifampicin was noted for 67 isolates (8.7%), with resistance to both isoniazid and rifampicin (i.e. defined as multidrug-resistant disease) observed in 12 (1.6%) isolates. All of the multidrug-resistant isolates were M. tuberculosis, 10 were from the respiratory tract. The country of birth was known for 63 of 68 (92.6%) patients with a drug-resistant strain of M. tuberculosis or M. africanum; five were Australian-born and 58 (92.1%) had migrated from a total of 22 countries. One hundred and seven respiratory specimens had a nucleic acid amplification testing performed; 89 of 90 (98.9%) smear positives were nucleic acid amplification testing positive, whilst only 13 of 17 (76.5%) smear negative specimens were nucleic acid amplification testing positive. The 2001 laboratory data reveals a stable incidence rate and level of drug resistance in isolates from Australian patients with tuberculosis.

The Australian Mycobacterium Reference Laboratory Network collected and analysed laboratory data on new diagnoses of disease caused by Mycobacterium tuberculosis complex in the year 2000. A total of 765 cases were identified, representing an annual reporting rate of 4.0 cases of laboratory-confirmed tuberculosis (TB) per 100,000 population. Pulmonary disease was diagnosed in 64.9 per cent of cases with a male:female ratio of 1.5:1. Smears were positive for 209/365 (57.3%) of sputum isolates and 39/117 (33.3%) bronchoscopy isolates. Sputum from males was more likely to be smear-positive (63.3%) than from females (47.5%). Isolates from lymph node accounted for 136 (17.7%) of all cases; only 28.7 per cent were smear-positive. Eighty-four (11.0%) isolates, comprising 82 M. tuberculosis and 2 M. bovis strains, demonstrated in vitro resistance to at least one of the standard anti-TB medications. Resistance to at least isoniazid and rifampicin (defined as multidrug-resistant TB) was observed for only 8 (1.0%) strains, a rate similar to previous years. Almost all (96.3%) of patients with drug resistant strains were classified as having initial resistance. The country of birth was known for 76 (92.7%) of 82 patients with a drug resistant strain of M. tuberculosis; 6 were Australian-born and 70 (92.1%) had migrated from a total of 17 countries. Of these 70 migrants with drug-resistant disease, 68.6 per cent had migrated from one of the following countries: Vietnam (n=15), China (n=11), Philippines (n=11), India (n=6), and Indonesia (n=5).