In the textbook The Power of Plagues (copyright 2017), Irwin Sherman describes tuberculosis (Mycobacterium tuberculosis) as most likely having originated in cows. A similar bovine parasite, Mycobacterium bovis is also capable of being transmitted to humans, though it is not transmitted through the air and does not thrive in oxygen-rich environments as pulmonary tuberculosis does. Ancient Egyptian mummies have been found infected with tuberculosis in the vertebrae of the spine, suggesting that the disease spread from M. bovis in cattle after domestication and then developed in pulmonary form. In mummies dated after 4000 B.C.E. pulmonary tuberculosis had been discovered, and the disease is believed to have spread by nomadic Indo-European tribes to the Middle East, Greece, and India through. Despite being endemic in much of the known world (including most of Europe during the Middle Ages), tuberculosis was not suspected to be infectious until 1772 with the observations of Benjamin Marten.

With the emergence and development of large cities and towns by 1780, a new wave of tuberculosis hit England, followed through the years by many cities across Eastern Europe and North America. The closer proximity of people and their dairy cows to the community center meant more transmission of tuberculosis between people, as well as between cows and across the two species. During the nineteenth century there was a large influx of immigrants (including refugees of the potato blight, as discussed in the previous artifact) to the US, and tightly packed tenement housing facilitated the spread of the disease. Lack of ventilation in the tenements, especially during cold winter months when windows remained shut, meant very little fresh air and high likelihood for previously healthy individuals to contract the disease. Aside from being housed close together, poor immigrants were often malnourished, weakening immune systems’ ability to fight off the bacteria.

In 1882, physician Robert Koch was able to identify M. tuberculosis despite its colorless cells and difficulty to stain (the waxy cell walls were later discovered to retain dye with the help of an acid wash and the cells are Gram positive). In 1890 the extract used in the modern PPD test for tuberculosis was developed. During the twentieth century the disease was romanticized in books and movies, such as the 1936 movie Camille. As discussed in class, the pale and wasted look of the sick was considered beautiful and even associated with increased creativity and artistic work.

Due to its ability to be spread through simple inhalation, tuberculosis infections often go unnoticed or dismissed as a simple cold. According to the textbook (p. 337), in 85-90% of cases the infection goes no further than division of the bacilli throughout the body and formation of visible tubercles in the lung, calcified by the immune response and therefore making the disease latent (ie not actively harming the infected person or infecting other people). The danger of this is that the infection can be later reactivated (some 5-10% of cases becoming active at a later date). Penicillin was completely ineffective against tuberculosis, and strains of TB quickly became resistant to the newly-discovered streptomycin. Other drugs such as para-aminosalicylic acid (PAS) and isoniazid were developed, followed by others to form the veritable cocktail of drugs used today to treat tuberculosis while minimizing resistance.

Improved sanitation measures such as cleaner cities, elimination of tubercular cows, better nutrition, and higher standards of living also led to a decline in TB by the 1940s. Unfortunately, with the rise of HIV and subsequent weakened immune systems, incidences of TB have risen in slums and other poverty-stricken areas, particularly in India, Indonesia, and China. Multidrug and extremely drug resistant cases of TB have emerged, and according to a recent Healthline News article (“Why Tuberculosis Has Been So Difficult to Eradicate”) TB prevention is made more difficult by the fact that existing vaccines don’t work well in adults and render the current test for latent TB ineffective. To eliminate the so-called People’s Plague, especially now that the world is faced with HIV that weakens so many immune systems, it is important that research continue to develop more effective medicines and vaccines, while public health and sanitation in poverty-stricken countries be improved to minimize the spread.

HR: References as listed in text, class discussion, Microsoft Word for spelling/grammar check