RT Book, Section A1 Raviglione, Mario C. A2 Kasper, Dennis L. A2 Fauci, Anthony S. SR Print(0) ID 1141409526 T1 TUBERCULOSIS T2 Harrison's Infectious Diseases, 3e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9781259835971 LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1141409526 RD 2024/10/09 AB Tuberculosis (TB), which is caused by bacteria of the Mycobacterium tuberculosis complex, is one of the oldest diseases known to affect humans and a major cause of death worldwide. Recent population genomic studies suggest that M. tuberculosis may have emerged ~70,000 years ago in Africa and subsequently disseminated along with anatomically modern humans, expanding globally during the Neolithic Age as human density started to increase. ­Progenitors of M. tuberculosis are likely to have affected prehominids. This disease most often affects the lungs, although other organs are involved in up to one-third of cases. If properly treated, TB caused by drug-­susceptible strains is curable in the vast majority of cases. If untreated, the disease may be fatal within 5 years in 50–65% of cases. Transmission usually takes place through the airborne spread of droplet nuclei produced by patients with infectious pulmonary TB.