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Strep or Sore Throat Slideshow Pictures Take the MRSA Quiz! Infectious Mononucleosis Slideshow Pictures

Medical Author:

Steven Doerr, MD

Steven Doerr, MD

Steven Doerr, MD, is a U.S. board-certified Emergency Medicine Physician. Dr. Doerr received his undergraduate degree in Spanish from the University of Colorado at Boulder. He graduated with his Medical Degree from the University Of Colorado Health Sciences Center in Denver, Colorado in 1998 and completed his residency training in Emergency Medicine from Denver Health Medical Center in Denver, Colorado in 2002, where he also served as Chief Resident.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

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.

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What is diphtheria?

Diphtheria is an infectious disease caused by the bacterium Corynebacterium diphtheriae. This disease primarily affects the mucous membranes of the respiratory tract (respiratory diphtheria), although it may also affect the skin (cutaneous diphtheria) and lining tissues in the ear, eye, and the genital areas.

What is the history of diphtheria?

Throughout history, diphtheria was a leading cause of death among children, and it was once referred to as the "strangling angel of children." Through the ages, several epidemics struck Europe, and even the American colonies were affected by an outbreak in the 18th century. Most recently, in the 1990s, large outbreaks of diphtheria occurred in Russia and in the former independent states of the Soviet Union.

The diphtheria bacterium was first identified in the 1880s. In the 1890s, the antitoxin against diphtheria was developed, with the first vaccine being developed in the 1920s. With the development and administration of the diphtheria vaccine, the incidence of diphtheria has decreased significantly. Though it is still endemic in many parts of the world, respiratory diphtheria has now became a rare disease in the United States (with up to five cases per year). Furthermore, whereas diphtheria primarily affected younger children in the prevaccination era, an increasing proportion of cases today occur in unvaccinated or inadequately immunized adolescents and adults.

What causes diphtheria?

Diphtheria is caused by toxin-producing strains of the gram-positive bacillus Corynebacterium diphtheriae. There are four biotypes of the bacterium (gravis, mitis, intermedius, and belfanti), and each differs in the severity of disease it produces. Nontoxigenic strains are usually responsible for less severe cutaneous diphtheria.

The signs and symptoms of respiratory diphtheria are caused by the bacterium's ability to cause a localized inflammatory reaction of the cells lining the upper respiratory tract. In certain cases, the disease can become more severe and widespread, and it can involve other organs of the body as well.