Dr. Schiffman received his B.S. degree with High Honors in biology from Hobart College in 1976. He then moved to Chicago where he studied biochemistry at the University of Illinois, Chicago Circle. He attended Rush Medical College where he received his M.D. degree in 1982 and was elected to the Alpha Omega Alpha Medical Honor Society. He completed his Internal Medicine internship and residency at the University of California, Irvine.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
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), originally an antidepressant medication, 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 of Mycobacteria 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 hygiene and health-care resources and high numbers of people infected with
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
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.
In 2009, the TB rate in the United States was 3.8 cases per 100,000 population, a slight decrease from the prior year. Four states (California, Florida, New York, and Texas) accounted for the majority of all new TB cases (50.3%).
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.
In 1993, the WHO declared tuberculosis a global emergency.
All cases of TB are passed from person to person via droplets. When someone with TB infection coughs, sneezes, or talks, tiny droplets of saliva or mucus are expelled into the air, which can be inhaled by another person.
Once infectious particles reach the alveoli (small saclike structures in the air spaces in the lungs), another cell, called the macrophage, engulfs the TB bacteria.
Then the bacteria are transmitted to the lymphatic system and bloodstream and spread to other organs occurs.
The bacteria further multiply in organs that have high oxygen pressures, such as the upper lobes of the lungs, the kidneys, bone marrow, and meninges -- the membrane-like coverings of the brain and spinal cord.