My wife always tests positive with the Mantoux tuberculin skin test, the most common screening test for TB. She grew up in Kenya and was most likely exposed when she was young sufficiently to produce an antibody response without being infected. False positives in the Mantoux test are fairly common, leading to chest X-rays and sputum cultures being truly diagnostic. So I have had an unusually significant number of interactions with TB for a first world citizen.
TB has certainly been around since 9000 BC and probably became a human disease as a consequence of the domestication of cattle. Evidence has been found in Egyptian mummies from circa 3000 BC. TB has been a scourge of humanity for all this time. The death toll peaked in the 18th century when accounted for ~25% of all fatalities. The advent of the sanitarium movement followed by modern antibiotics with the discovery of streptomycin in 1946 made total eradication of TB seem like an obtainable goal. Then in the 1980’s the first drug resistant isolates were found, and we returned to the old days of an untreatable TB.
Since 1980 reported cases of tuberculosis have been rising steadily from 1,000,000/year to over 5,000,000/ year . Approximately 1/3 of the world’s population is infected, and 3.7% of new and 20% reinfections involve some form of drug resistance. Total drug resistant TB has been found in Italy, India and Iran. It is unclear how extensive this strain is. Only 9% of TB cases are drug tested worldwide, making the extent of the problem largely unknown.