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Tuberculosis

Tuberculosis Overview

Tuberculosis (TB) describes an infectious disease that has plagued humans since the Neolithic times. Two organisms cause tuberculosis -- Mycobacterium tuberculosis and Mycobacterium bovis.

Physicians in ancient Greece called this illness "phthisis" to reflect its wasting character. During the 17th and 18th centuries, TB caused up to 25% of all deaths in Europe. In more recent times, tuberculosis has been called "consumption."

Robert Koch isolated the tubercle bacillus in 1882 and established TB as an infectious disease.

In the 19th century, patients were isolated in sanatoria and given treatments such as injecting air into the chest cavity. Attempts were made to decrease lung size by surgery called thoracoplasty.

During the first half of the 20th century, no effective treatment was available.

Streptomycin, the first antibiotic to fight TB, was introduced in 1946, and isoniazid (Laniazid, Nydrazid) became available in 1952.

M. tuberculosis is a rod-shaped, slow-growing bacterium.

M. tuberculosis' cell wall has high acid content, which makes it hydrophobic, resistant to oral fluids.

The cell wall absorbs a certain dye used in the preparation of slides for examination under the microscope and maintains this red color despite attempts at decolorization, hence the name acid-fast bacilli.

M. tuberculosis continues to kill millions of people yearly worldwide. In 1995, 3 million people died from TB.

More than 90% of TB cases occur in developing nations that have poor resources and high numbers of people infected with HIV.

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.

Tuberculosis continues to be a major health problem worldwide. In 2008, the World Health Organization (WHO) estimated that one-third of the global population was infected with TB bacteria.

8.8 million new cases of TB developed.

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.

With the spread of AIDS, tuberculosis continues to lay waste to large populations. The emergence of drug-resistant organisms threatens to make this disease once again incurable.