Intercontinental translocation of latent multidrug‐resistant tuberculosis to Australia demonstrated by whole genome sequencing

TO THE EDITOR: In 2016, there were an estimated 490 000 cases globally of multidrug‐resistant (MDR) tuberculosis exhibiting resistance to isoniazid and rifampicin.1 The first case of MDR tuberculosis diagnosed in Tasmania occurred in 2016 in a Vietnamese‐born person. Vietnam was the second highest reported country of birth for overseas‐born patients with tuberculosis notified in Australia in 2014.2 The patient had previously tested positive for tuberculosis infection in an interferon‐γ release assay test performed in Tasmania in early 2016, but at the time, the patient was asymptomatic and had a normal chest x‐ray and a negative sputum culture. After an episode of colitis, a colon tissue biopsy specimen isolated Mycobacterium tuberculosis. Whole genome sequence of the isolate (TASMDR1), identified high confidence mutations for isoniazid, rifampicin, ethambutol and pyrazinamide, in accordance with the culture‐based drug susceptibility testing, and, in addition, it identified a mutation associated with streptomycin resistance.3