XDRTB.org is an extraordinary effort to tell the story of extremely drug-resistant tuberculosis (XDR-TB) and TB through powerful photographs taken by James Nachtwey. XDR-TB, or extremely drug-resistant tuberculosis, is a new and deadly mutation of tuberculosis. Similar in creation to multidrug-resistant tuberculosis (MDR-TB) but more extreme in its manifestation, it arises when common tuberculosis goes untreated or standard TB drugs are misused. James’ photographs represent these varying strains. Learn more about TB, MDR-TB and XDR-TB, and learn how you can take action to stop this deadly disease.