Extensively drug resistant tuberculosis in a high income country: A report of four unrelated cases

Multi drug resistance of Mycobacterium tuberculosis (M. tuberculosis) remains a major threat to public health, reinforced by recent reports about the clinical course of patients infected with extensively drug resistant (XDR) strains in South Africa. There is little information about the clinical course of XDR tuberculosis patients in industrialised countries. We evaluated all isolates of M. tuberculosis, in which drug susceptibility testing was...