I didn't have time in class to tell you the story behind the discovery of XDR-TB. Only discovered in 2006 it was was first reported as a cluster of 53 patients in a rural hospital in South Africa - 52 of whom died. The strain of TB they had did not respond to any of the drugs then available in South Africa for first- or second-line treatment of TB. In addition it killed patients very quickly, something TB does not usually do. This was the epidemic for which the acronym XDR-TB was first coined. Over the next few months there were 314 cases reported, with 215 deaths. The story of the discovery of the resistance in these cases and the interaction between HIV and TB is told in this fascinating article.
Nesri Padayatchi, deputy director of the Centre for the AIDS Programme of Research in South Africa, tells of 35 patients treated with a second-line drug that causes intense nausea. Eight of them, she says, "tried it and said, 'I would rather die.'"
Doctors whose patients face resistant TB can't turn to "third-line" drugs: none exists.
There's a link below to some recent cases of XDR-TB in Botswana.