Tuberculosis has been present in humans since antiquity. The earliest unambiguous detection of ''Mycobacterium tuberculosis'' is in the remains of bison dated 18,000 years before the present. Whether tuberculosis originated in cattle and then transferred to humans, or diverged from a common ancestor infecting a different species, is currently unclear. However, it is clear that ''M. tuberculosis'' is not directly descended from ''M. bovis'', which seems to have evolved relatively recently.
Skeletal remains from a Neolithic Settlement in the Eastern Mediterranean show prehistoric humans (7000 BC) had TB, and tubercular decay has been found in the spines of mummies from 3000–2400 BC. Phthisis is a Greek term for tuberculosis; around 460 BC, Hippocrates identified phthisis as the most widespread disease of the times involving coughing up blood and fever, which was almost always fatal. In South America, the earliest evidence of tuberculosis is associated with the Paracas-Caverna culture (circa 750 BC to circa 100 AD).
Other names
In the past, tuberculosis has been called consumption, because it seemed to consume people from within, with a bloody cough, fever, pallor, and long relentless wasting. Other names included ''phthisis'' (Greek for consumption) and ''phthisis pulmonalis''; scrofula (in adults), affecting the lymphatic system and resulting in swollen neck glands; ''tabes mesenterica'', TB of the abdomen and ''lupus vulgaris'', TB of the skin; wasting disease; white plague, because sufferers appear markedly pale; king's evil, because it was believed that a king's touch would heal scrofula; and Pott's disease, or gibbus of the spine and joints.
''Miliary tuberculosis''—now commonly known as disseminated TB—occurs when the infection invades the circulatory system, resulting in lesions which have the appearance of millet seeds on X-ray. TB is also called Koch's disease, after the scientist Robert Koch.
Folklore
Before the Industrial Revolution, tuberculosis may sometimes have been regarded as vampirism. When one member of a family died from it, the other members that were infected would lose their health slowly. People believed that this was caused by the original victim draining the life from the other family members. Furthermore, people who had TB exhibited symptoms similar to what people considered to be vampire traits. People with TB often have symptoms such as red, swollen eyes (which also creates a sensitivity to bright light), pale skin, extremely low body heat, a weak heart and coughing blood, suggesting the idea that the only way for the afflicted to replenish this loss of blood was by sucking blood. Another folk belief told that the affected individual was being forced, nightly, to attend fairy revels, so that the victim wasted away owing to lack of rest; this belief was most common when a strong connection was seen between the fairies and the dead. Similarly, but less commonly, it was attributed to the victims being "hagridden"—being transformed into horses by witches (hags) to travel to their nightly meetings, again resulting in a lack of rest. In the early 20th century, some believed TB to be caused by masturbation.
Study and treatment
The study of tuberculosis, sometimes known as phthisiatry, dates back to ''The Canon of Medicine'' written by Ibn Sina (Avicenna) in the 1020s. He was the first physician to identify pulmonary tuberculosis as a contagious disease, the first to recognise the association with diabetes, and the first to suggest that it could spread through contact with soil and water. He developed the method of quarantine in order to limit the spread of tuberculosis. In ancient times, treatments focused on sufferers' diets. Pliny the Elder described several methods in his ''Natural History'': "wolf's liver taken in thin wine, the lard of a sow that has been fed upon grass, or the flesh of a she-ass taken in broth".
Although it was established that the pulmonary form was associated with "tubercles" by Dr Richard Morton in 1689, due to the variety of its symptoms, TB was not identified as a single disease until the 1820s and was not named "tuberculosis" until 1839 by J. L. Schönlein. During the years 1838 – 1845, Dr. John Croghan, the owner of Mammoth Cave, brought a number of tuberculosis sufferers into the cave in the hope of curing the disease with the constant temperature and purity of the cave air; they died within a year. The first TB sanatorium opened in 1854 in Görbersdorf, Germany (today Sokołowsko, Poland) by Hermann Brehmer.
The bacillus causing tuberculosis, ''Mycobacterium tuberculosis'', was identified and described on 24 March 1882 by Robert Koch. He received the Nobel Prize in physiology or medicine in 1905 for this discovery. Koch did not believe that bovine (cattle) and human tuberculosis were similar, which delayed the recognition of infected milk as a source of infection. Later, this source was eliminated by the pasteurization process. Koch announced a glycerine extract of the tubercle bacilli as a remedy for tuberculosis in 1890, calling it "tuberculin". It was not effective, but was later adapted as a test for pre-symptomatic tuberculosis.
The first genuine success in immunizing against tuberculosis was developed from attenuated bovine-strain tuberculosis by Albert Calmette and Camille Guérin in 1906. It was called "BCG" (Bacillus of Calmette and Guérin). The BCG vaccine was first used on humans in 1921 in France, In 1815, one in four deaths in England was of consumption; by 1918 one in six deaths in France were still caused by TB. In the 20th century, tuberculosis killed an estimated 100 million people. After the establishment in the 1880s that the disease was contagious, TB was made a notifiable disease in Britain; there were campaigns to stop spitting in public places, and the infected poor were pressured to enter sanatoria that resembled prisons; the sanatoria for the middle and upper classes offered excellent care and constant medical attention.
It was not until 1946 with the development of the antibiotic streptomycin that effective treatment and cure became possible. Prior to the introduction of this drug, the only treatment besides sanatoria were surgical interventions, including the pneumothorax or plombage technique — collapsing an infected lung to "rest" it and allow lesions to heal — a technique that was of little benefit and was mostly discontinued by the 1950s. The emergence of multidrug-resistant TB has again introduced surgery as part of the treatment for these infections. Here, surgical removal of chest cavities will reduce the number of bacteria in the lungs, as well as increasing the exposure of the remaining bacteria to drugs in the bloodstream. It is therefore thought to increase the effectiveness of the chemotherapy.
Hopes that the disease could be completely eliminated have been dashed since the rise of drug-resistant strains in the 1980s. For example, tuberculosis cases in Britain, numbering around 117,000 in 1913, had fallen to around 5,000 in 1987, but cases rose again, reaching 6,300 in 2000 and 7,600 cases in 2005. Due to the elimination of public health facilities in New York and the emergence of HIV, there was a resurgence of TB in the late 1980s. The number of patients failing to complete their course of drugs is high. New York had to cope with more than 20,000 TB patients with multidrug-resistant strains (resistant to, at least, both Rifampin and Isoniazid).
The resurgence of tuberculosis resulted in the declaration of a global health emergency by the World Health Organization (WHO) in 1993. Every year, nearly half a million new cases of multidrug-resistant tuberculosis (MDR-TB) are estimated to occur worldwide.
Evolution
Tuberculosis has co-evolved with humans for many thousands of years, and perhaps for several million years. The oldest known human remains showing signs of tuberculosis infection are 9,000 years old. During this evolution, ''M. tuberculosis'' has lost numerous coding and non-coding regions in its genome, losses that can be used to distinguish between strains of the bacteria. The implication is that ''M. tuberculosis'' strains differ geographically, so their genetic differences can be used to track the origins and movement of each strain.
Further Reading
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