Tb rev3
- 1. Dave Martin Tuberculosis (TB) Wednesday, July 14, 2011 What is Tuberculosis? TB is a bacterial infection caused by the bacteria Mycobacterium Tuberculosis or Tubercle Bacillus. It attacks the lining of the lungs causing lesions which in tune cause bleeding coughing spells. Beginning with infections in the upper part of the lower lobe or the lower part of the upper lobe it spreads through the blood stream to other organs. Secondary TB lesions can develop in peripheral lymph nodes, kidneys, brain or bone. In fact, all parts of the body can be affected by TB, however the heart, pancreas, thyroid and skeletal muscles are rarely affected. 90% of people who are infected with TB are infected with Latent TB. That is, the infecting bacteria remain dormant in the body, inactive; no symptoms are evident and the carrier is not contagious. The carrier is however at risk of developing Active TB. Active TB will develop in patients with a weakened immune system causing symptoms and the carrier will become contagious. 10% of people with Latent TB develop active cases of the disease. Active TB is most common in people with HIV. Recent immigrants from countries where TB is widespread and those who live in inner cities are more likely to be carriers of TB. Tuberculosis continues to be a major health problem worldwide. In 2008, the World Health Organization estimated that one third of the global population was infected with TB bacteria. How do you get it? By inhaling minute particles, of infected sputum from the air, one can obtain the tuberculosis disease. The bacteria get into the air when someone who has a tuberculosis lung infection: coughs, sneezes, shouts, or spits (which is common in some cultures). When people suffering from active pulmonary TB, cough, sneeze, speak, sing, or spit, they expel infectious aerosol
- 2. Dave Martin droplets 0.5 to 5 µm in diameter. A single sneeze can release up to 40,000 droplets. Since the infectious dose of tuberculosis is very low, and inhaling fewer than ten bacteria may cause an infection, each one of these droplets may transmit the disease. There is a form of atypical tuberculosis, which transmitted by drinking unpasteurized milk. Related bacteria, called Mycobacterium bovis, cause this form of TB. Previously, this type of bacteria was a major cause of TB in children, but it rarely causes TB now since most milk is pasteurized (undergoes a heating process that kills the bacteria). How do you treat it? The standard "short" course treatment for TB is isoniazid (an antibiotic that kills the bacteria that causes TB), rifampicin (also known as rifampin in the United States), pyrazinamide, and ethambutol for two months, followed by isoniazid and rifampicin alone for another four months. At six months (although there is still a relapse rate of 2 to 3%), the patient is considered cured. History: TB was commonly known as Consumption in the 18th and 19th centuries, due to its wasting away of victims. It was first isolated in 1882 by a German physician named Robert Koch, who received the Nobel Prize for this discovery. Other names include 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. 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.
- 3. Dave Martin 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). Suzanne Austin Alchon wrote that, skeletal remains from prehistoric North America indicate that the disease was so common that virtually every member of these late prehistoric communities had primary exposure to tuberculosis. The oldest known human remains showing signs of tuberculosis infection are over 9,000 years old. During this period, 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. Folklore: Before the Industrial Revolution, tuberculosis was sometimes regarded as vampirism. When one member of a family died from it, the other members that were infected would lose their health slowly. Folklore held 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
- 4. Dave Martin 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. TB was romanticized in the nineteenth century. Many people believed TB produced feelings of euphoria referred to as Spes phthisica ("hope of the consumptive"). It was believed that TB sufferers who were artists had bursts of creativity as the disease progressed. It was also believed that TB sufferers acquired a final burst of energy just before they died that made women more beautiful and men more creative. Epidemiology: Roughly a third of the world's population has been infected with M. tuberculosis, and new infections occur at a rate of one per second. However, not all infections with M. tuberculosis cause TB disease and many infections are asymptomatic. In 2007, an estimated 13.7 million people had active TB disease, with 9.3 million new cases and 1.8 million deaths; the annual incidence rate varied from 363 per 100,000 in Africa to 32 per 100,000 in the Americas. Tuberculosis is the world's greatest infectious killer of women of reproductive age and the leading cause of death among people with HIV/AIDS. The rise in HIV infections and the neglect of TB control programs have enabled a resurgence of tuberculosis. The emergence of drug-resistant strains has also contributed to this new epidemic with, from 2000 to 2004, 20% of TB cases being resistant to standard treatments and 2% resistant to second-line drugs. The rate at which new TB cases occur varies widely, even in neighboring countries, apparently because of differences in health care systems. In 2007, the country with the highest estimated incidence rate of TB was Swaziland, with 1200 cases per 100,000 people. India had the largest total incidence, with an estimated 2.0 million new cases. In developed countries, tuberculosis is less common and is mainly an urban disease. In the United Kingdom, the national average was 15 per 100,000 in 2007, and the highest incidence rates in Western Europe were 30 per 100,000 in Portugal and Spain. These rates compared with 98 per 100,000 in China and 48 per 100,000 in Brazil. In the United States, the overall
- 5. Dave Martin tuberculosis case rate was 4 per 100,000 persons in 2007. In Canada tuberculosis is still endemic in some rural areas. Demographics: In the United States, the incidence of TB began to decline around 1900 because of improved living conditions. TB cases have increased since 1985, most likely due to the increase in HIV infection. Mycobacterium Tuberculosis (M. Tuberculosis) continues to kill millions of people yearly worldwide. In 1995, 3 million people died from TB worldwide. More than 90% of TB cases occur in developing nations that have poor hygiene and health-care resources and high numbers of people infected with HIV. 8.8 million new cases of TB are developing each year. 1.6 million people died of this disease in 2005. Each person with untreated active TB will infect on average 10-15 people each year. A new infection occurs every second. In 2009, the TB rate in the United States was 3.8 cases per 100,000 population, a slight decrease from the prior year. California, Florida, New York, and Texas accounted for the majority of all new TB cases (50.3%) primarily due to the unchecked illegal immigration from Mexico.
- 6. Dave Martin Bibliography Pulmonary tuberculosis www.ncbi.nlm.nih.gov Tuberculosis - Wikipedia en.wikipedia.org/wiki/Tuberculosis Tuberculosis (TB) Symptoms, Cause, Transmission, Diagnosis and Treatment www.medicinenet.com/tuberculosis/article.htm CDC - Tuberculosis (TB) www.cdc.gov/tb/ Tuberculosis: MedlinePlus www.nlm.nih.gov/medlineplus/tuberculosis.html http://en.wikipedia.org/wiki/Tuberculosis - cite_note-Hershkovitz_2008-122 Wikipedia: Tuberculosis Treatment Wikipedia: Tuberculosis E Medicine Health Insel, Paul M., and Walton T. Roth. Core Consepts in Health. 11th ed. San Francisco: The McGraw- Hill Companies, 2010. 324-25. Print. http://infectiousdiseases.about.com/od/respiratoryinfections/a/active_tb.htm