K D Dale1, M Globan2, E L Tay3, J M Trauer4, P G Trevan1, J T Denholm5. 1. Victorian Tuberculosis Program, Parkville. 2. Mycobacterium Reference Laboratory, Victorian Infectious Diseases Reference Laboratory, Melbourne. 3. Department of Health and Human Services, Melbourne. 4. Victorian Tuberculosis Program, Parkville, School of Public Health and Preventive Medicine, Monash University, Clayton. 5. Victorian Tuberculosis Program, Parkville, Department of Microbiology and Immunology, The University of Melbourne, Melbourne, Victoria, Australia.
Abstract
SETTING: Victoria, Australia, is an industrialised setting with low tuberculosis (TB) incidence and universal health care. Individually tailored adherence support for self-administered daily anti-tuberculosis treatment is provided. Directly observed treatment (DOT) is very rarely used. OBJECTIVE: To review the rate of recurrent TB in Victoria between 2002 and 2014. DESIGN: This was a retrospective cohort study. All recurrent episodes of TB were reviewed and 24-locus MIRU-VNTR (mycobacterial interspersed repetitive units-variable number of tandem repeats) molecular typing was used where possible to determine the likelihood of relapse or reinfection. RESULTS: Of 4766 notifications, 32 (0.7%) were recurrent episodes. Of 20 episodes that occurred in patients who had previously completed treatment, 11 were culture-positive (0.4% of 3012 culture-positive episodes): 9 were likely relapses (distinguishable at no more than one of 24 loci) and two were likely reinfections, giving a TB relapse rate among culture-positive episodes of 52.5/100 000 person-years (mean time to study end per patient of 5.7 years). The median time until relapse was 18 months (interquartile range 12-30). CONCLUSIONS: The low rate of relapse in our setting demonstrates that individually tailored adherence support for self-administered anti-tuberculosis treatment can achieve excellent treatment outcomes.
SETTING: Victoria, Australia, is an industrialised setting with low tuberculosis (TB) incidence and universal health care. Individually tailored adherence support for self-administered daily anti-tuberculosis treatment is provided. Directly observed treatment (DOT) is very rarely used. OBJECTIVE: To review the rate of recurrent TB in Victoria between 2002 and 2014. DESIGN: This was a retrospective cohort study. All recurrent episodes of TB were reviewed and 24-locus MIRU-VNTR (mycobacterial interspersed repetitive units-variable number of tandem repeats) molecular typing was used where possible to determine the likelihood of relapse or reinfection. RESULTS: Of 4766 notifications, 32 (0.7%) were recurrent episodes. Of 20 episodes that occurred in patients who had previously completed treatment, 11 were culture-positive (0.4% of 3012 culture-positive episodes): 9 were likely relapses (distinguishable at no more than one of 24 loci) and two were likely reinfections, giving a TB relapse rate among culture-positive episodes of 52.5/100 000 person-years (mean time to study end per patient of 5.7 years). The median time until relapse was 18 months (interquartile range 12-30). CONCLUSIONS: The low rate of relapse in our setting demonstrates that individually tailored adherence support for self-administered anti-tuberculosis treatment can achieve excellent treatment outcomes.