“…How long, if at all, do patients with MDR tuberculosis require isolation or separation in hospital, and do they actually require hospitalisation for transmission-control purposes? On the basis of household contact studies, Rouillon and colleagues 465 in 1976 first proposed 2 weeks of effective treatment as the minimum duration necessary to render tuberculosis patients non-infectious. The authors emphasise that most patients are not smear-negative or culture-negative after 2 weeks (converting, on average, at about 2 months), concluding that smear and culture predicted patient infectiousness before the onset of effective therapy, but not once started.…”