Tuberculosis is a chronic or acute infection caused by bacteria called Mycrobacterium tuberculosis. Tuberculosis mainly affects the lungs but can also attack kidneys, bones, lymph nodes and brain.  When localized to the lungs, tuberculosis can run an acute course, causing extensive destruction in a few months so-called galloping consumption.  It can also wax and wane with periods of remission mistaken in some cases for chronic bronchitis with spitting up of blood.  Tuberculosis can affect organs other than the lungs, including the intestine and larynx, sometimes the lymph nodes in the neck are affected, producing a swelling called scrofula.  Modern strains of Mycobacterium tuberculosis appear to have originated from a common ancestor about 20,000-15,000 years ago.  By Laennec’s era, tuberculosis had surged across Europe in an epidemic tsunami.  Death rates in London, Stockholm, and Hamburg approached 800-1000/100,000year at that time.