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Diphtheria is an upper respiratory tract illness characterized by sore throat, low-grade fever, and an adherent membrane of the tonsil(s), pharynx, and/or nose. A milder form of diphtheria can be limited to the skin. It is caused by Corynebacterium diphtheriae, an aerobic Gram-positive bacterium.
Diphtheria is a highly contagious disease spread by direct physical contact or breathing the secretions of those infected. Diphtheria was once quite common, but has now largely been eradicated in developed nations (in the United States for instance, there have been fewer than 5 cases a year reported since 1980, as the DPT (Diphtheria-Tetanus-Pertussis) vaccine is given to all school children). Boosters of the vaccine are recommended for adults because the benefits of the vaccine decrease with age; they are particularly recommended for those travelling to areas where the disease has not been eradicated yet.
Signs and symptoms
The respiratory form has an incubation time of 1-4 days. Symptoms include fatigue, fever, a mild sore throat and problems swallowing. Children infected have symptoms that include nausea, vomiting, chills, and a high fever, although some do not show symptoms until the infection has progressed further.
- Isolation of Corynebacterium diphtheriae from a clinical specimen, or
- Histopathologic diagnosis of diphtheria
- Probable: a clinically compatible case that is not laboratory confirmed and is not epidemiologically linked to a laboratory-confirmed case
- Confirmed: a clinically compatible case that is either laboratory confirmed or epidemiologically linked to a laboratory-confirmed case
Empirical treatment should generally be started in a patient in whom suspicion of diptheria is high.
The disease may remain manageable, but in more severe cases lymph nodes in the neck may swell, and breathing and swallowing will be more difficult. People in this stage should seek immediate medical attention, as obstruction in the throat may require a tracheotomy. In addition, an increase in heart rate may cause cardiac arrest. Diphtheria can also cause paralysis in the eye, neck, throat, or respiratory muscles. Patients with severe cases will be put in ICUs (Intensive Care Units) at hospitals and be given a diphtheria anti-toxin and bactericidal drugs such as penicillin and erythromycin. Bed rest is important and physical activity should be limited, especially in cases where there is inflammation of the heart muscles. Recovery is generally slow.
Diphtheria remains a serious disease, with 5-10% percent fatality and up to 20% in children younger than 5 or adults older than 40. Outbreaks, though very rare, still can occur worldwide, even in developed nations. After the breakup of the old Soviet Union in the late 1980s, vaccination rates fell so low that there was an explosion of diphtheria cases. In 1991 there were 2,000 cases of diphtheria in Russia and its newer independent states. By 1998 there were as many as 200,000 cases, with 5,000 deaths, according to Red Cross estimates. This was so great an increase that it was cited in the Guinness Book of World Records as "most resurgent disease".
Such statistics show that constant vigilance must be maintained even on largely eradicated diseases, especially since many of these diseases show growing resistance to drugs that have been used to fight them for decades.
From the CDC guidelines:
- Cutaneous diphtheria should not be reported. Respiratory disease caused by nontoxigenic C. diphtheriae should be reported as diphtheria.
All diphtheria isolates, regardless of association with disease, should be sent to the Diphtheria Laboratory, National Center for Infectious Diseases, CDC.
Diphtheria (dif-thir-ee-uh or often dip-thir-ee-uh) takes its name from the Greek word for "leather", dipthera, and was named in 1855 by French physician Armand Trousseau (1801-1867). This coinage alludes to the leathery, sheath-like membrane that grows on the tonsils, throat and in the nose.
Diphtheria was once one of the most dreaded diseases, with frequent large-scale outbreaks. From 1735-1740, a diptheria epidemic in the New England colonies was said to have killed as much as 80% of the children under 10 years of age in some towns. In 1920s there were an estimated 100,000 to 200,000 cases a year of diphtheria in the United States, with 13,000 to 15,000 deaths. Children represented the large majority of cases and fatalities.
One of the first early effective treatments was discovered in the 1880s by U.S. physician Joseph O'Dwyer (1841-1898). O'Dwyer developed tubes that could be inserted into the throat to prevent victims from suffocating from the membrane sheath that grew and obstructed the airways. In the 1890s, the German physician Emil von Behring developed an anti-toxin that, although it did not kill the bacteria, neutralized the toxic poisons that the bacteria released into the body. For this (and his serum therapy for diphtheria), he won the first Nobel Prize in Medicine. (Americans William H. Park and Anna Wessels Williams also developed a diptheria antitoxin in the 1890s.) Effective vaccines were not developed until the discovery and development of sulfa drugs following World War II.
- The first version of this article was adapted from the CDC document "Diphtheria - 1995 Case Definition" at http://www.cdc.gov/epo/dphsi/casedef/diphtheria_current.htm. As a work of an agency of the U.S. Government without any other copyright notice it should be available as a public domain resource.
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