The aim of this study is to describe molecular typing of M.tuberculosis (M.tb), introduced as a collaborative study between the New Zealand Tb Reference Laboratory, Green Lane Hospital, and the Virology/Immunology DNA Department, Auckland Hospital. Molecular typing has been developed to assist in outbreak recognition, to identify laboratory cross-contamination, and to assist in the
... [Show full abstract] differentiation of reactivation versus re-infection with M.tb. Our method uses the repetitive and random insertion of IS6110 as a basis for DNA fingerprinting. This is in accordance with the standard reference method used worldwide. We report the use of this technology to resolve possible laboratory cross contamination, the analysis of three putative outbreaks of M.tb, and the contribution it has made to epidemiology. Immediate Public Health benefits resulted, including the unexpected identification of geographically widespread contact cases. The results indicate that this is a reliable, reproducible method for typing M.tb isolates. We conclude that significant advances in the control of M.tb may be anticipated by collating the typing patterns of all M.tb isolates in New Zealand.