Wednesday, February 4, 2009

History

HISTORY OF TUBERCULOSIS



Tubercular decay has been found in the spines of Egyptian mummies. Pictured: Egyptian mummy in the British Museum

Consumption, phthisis, scrofula, Pott's disease, and the White Plague are all terms used to refer to
tuberculosis throughout history. The term “phthisis”, consumption, appears first in Greek literature.





Around 460 BCE, Hippocrates identified phthisis as the most widespread disease of the times, and noted that it was almost always fatal. Tuberculosis (TB) is caused by Mycobacterium tuberculosis which has been present in the human population since antiquity - fragments of the spinal column from Egyptian mummies from 2400 BCE show definite signs of tuberculosis.
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 attributed it to 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.
TB was romanticized in the nineteenth century. Many people believed TB produced feelings of euphoria referred to as "Spes phthisica" or "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 which made women more beautiful and men more creative. In the early 20th century, some believed TB to be caused by
masturbation.

Study and treatment
The study of tuberculosis 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 recognize 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 1859 in Görbersdorf, Germany (today Sokołowsko, Poland) by Hermann Brehmer.
In regard to this claim, The Times for 15 January 1859, page 5, column 5, carries an advertisement seeking funds for the Bournemouth Sanatorium for Consumption, referring to the balance sheet for the past year, and offering an annual report to prospective donors, implying that this sanatorium was in existence at least in 1858.







Dr. Robert Koch discovered the tuberculosis bacilli.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.

































Albert Calmette Camille Guerin(from left-right)


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, but it was not until after World War II that BCG received widespread acceptance in the USA, Great Britain, and Germany.
Tuberculosis, or "consumption" as it was commonly known, caused the most widespread public concern in the 19th and early 20th centuries as an
endemic disease of the urban poor. 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
the fresh air and labor in the sanatoria, even under the best conditions, 50% of those who entered were dead within five years (1916).


The promotion of Christmas Seals began in Denmark during 1904 as a way to raise money for tuberculosis programs. It expanded to the United States and Canada in 1907 – 1908 to help the National Tuberculosis Association (later called the American Lung Association).
In the United States, concern about the spread of tuberculosis played a role in the movement to prohibit public spitting except into
spittoons. In Europe, deaths from TB fell from 500 out of 100,000 in 1850 to 50 out of 100,000 by 1950. Improvements in public health were reducing tuberculosis even before the arrival of antibiotics, although the disease remained a significant threat to public health, such that when the Medical Research Council was formed in Britain in 1913 its initial focus was tuberculosis research.
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 technique — collapsing an infected lung to "rest" it and allow lesions to heal — a technique that was of little benefit and was largely 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, and is therefore thought to increase the effectiveness of the chemotherapy.




How does it spread or how is it acquired?
When infectious people cough, sneeze, talk or spit, they propel TB germs, known as bacilli, into the air. A person needs only to inhale a small number of these to be infected. The body's immune (defense) system, however, can fight off the infection and stop the bacteria from spreading. The immune system does so ultimately by forming scar tissue around the TB bacteria and isolating it from the rest of the body. Tuberculosis that occurs after initial exposure to the bacteria is often referred to as primary TB. If the body is able to form scar tissue (fibrosis) around the TB bacteria, then the infection is contained in an inactive state. Such an individual typically has no symptoms and cannot spread TB to other people. The scar tissue and lymph nodes may eventually harden, like stone, due to the process of calcification of the
scars (deposition of calcium from the bloodstream in the scar tissue). These scars often appear on x-rays and imaging studies like round marbles and are referred to as a granuloma.
A person does not acquire TB by just merely touching the clothes or shaking the hands of someone who is infected. Tuberculosis spread (transmitted) primarily from person to person by breathing infected air during close contact.
What are the symptoms of tuberculosis?
generalized tiredness or weakness,
weight loss,
fever,
night sweats
chest pain,
coughing up of sputum (material from the lungs) and/or blood
shortness of breath.
How is tuberculosis diagnosed?
· Chest x-rays – which may show scarring (fibrosis) or hardening (calcification) in the lungs, suggesting that the TB is contained and inactive
· Analysis of sputum (sputum exam) - Examination of the sputum on a slide (smear) under the microscope can show the presence of the tuberculosis-like bacteria
· Skin tests – includes the Tine test and the
Mantoux test, also known as the PPD (purified protein derivative) test. In each of these tests, a small amount of purified extract from dead tuberculosis bacteria is injected under the skin. If a person is not infected with TB, then no reaction will occur at the site of the injection (a negative skin test). If a person is infected with tuberculosis, however, a raised and reddened area will occur around the site of the test injection. This reaction, a positive skin test, occurs about 48 to 72 hours after the injection

What is DOTS?
In the United States, this was known as Directly Observed Therapy, or DOT. But in 1994, WHO TB Programme Advocacy Officer Kraig Klaudt, modified the DOT acronym to include another key element of the strategy-the Short-course chemotherapy from SCC- gave meaning to "DOTS." Thus "DOTS" was born and Stop TB-Use DOTS became a clarion call for TB control programmes around the world.

How is tuberculosis treated?
A person with a positive skin test, a normal
chest x-ray, and no symptoms most likely has only a few TB germs in an inactive state and is not contagious. Nevertheless, treatment with an antibiotic may be recommended for this person to prevent the TB from turning into an active infection. The antibiotic used for this purpose is called isoniazid (INH). If taken for six to 12 months, it will prevent the TB from becoming active in the future. In fact, if a person with a positive skin test does not take INH, there is a 5%-10% lifelong risk that the TB will become active.
Active TB is treated with a combination of medications along with Isoniazid,
Rifampicin (Rifadin), Ethambutol (Myambutol), and Pyrazinamide are the drugs commonly used to treat active TB. Four drugs are often taken for the first two months of therapy to help kill any potentially resistant strains of bacteria. Then the number is usually reduced to two drugs for the remainder of the treatment based on drug sensitivity testing that is usually available by this time in the course. Streptomycin, a drug that is given by injection, may be used as well, particularly when the disease is extensive and/or the patients do not take their oral medications reliably (termed "poor compliance"). Treatment usually lasts for many months and sometimes for years. Successful treatment of TB is dependent largely on the compliance of the patient. Indeed, the failure of a patient to take the medications is the most important cause of failure to cure the TB infection. In some locations, the health department demands direct monitoring of patient compliance with therapy. Thus the 5 combination of the drugs that treat tuberculosis can be easily remembered by the following acronym R.I.P.E.S which pertains to Rifampicin, Isoniazid, Pyrazinamide, Ethambutol and Streptomycin.
Surgery on the lungs may also be indicated to help cure TB when medication has failed, but in this day and age, surgery for TB is unusual. Treatment with appropriate antibiotics will usually cure the TB. Without treatment, however, tuberculosis can be a lethal infection. Therefore, early diagnosis is important. Those individuals who have been exposed to a person with TB, or suspect that they have been, should be examined by a doctor for signs of TB and screened with a TB skin test.


What are the five major components of DOTS?
Political commitment and resources:TB control is a public health responsibility and top-down support is crucial. This component must be the strongest link in the chain.
Microscopy: Accurate diagnosis using sputum smear microscopy among symptomatic patients is the first step in early detection of active TB infection. It sets the DOTS cure cycle in motion and protects others from infection;
Treatment:Standardized 6-8 month regimens for all patients with active TB, with directly observed treatment for at least the first two months. The success of this phase is contingent upon a sound, functional health sector infrastructure and trained personnel;
Medicines: Regular, uninterrupted supplies of the 4-6 most effective anti- TB drugs is essential. Full compliance with the drug regimen means nine out of ten patients can be cured;
Monitoring: A standardized recording and reporting system allows assessment of each patient's treatment and progress. Rigorous overall record keeping also acts as early warning for emerging disease trends (e.g. MDR-TB).





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