CardiovascularWhat Is Diphtheria? What Causes Diphtheria?
Diphtheria is a bacterial infection in the upper respiratory tract. Typically it is characterized by sore throat, swollen neck glands, high temperature and breathing difficulties. Through means of successful immunization diphtheria is now very rare in the United States and Europe. However it"s still common in countries where immunization programs are not an integral part of standard public health care. It is a potentially fatal disease with an estimated 5-10% fatality rate. In children under 5 and adults over 40 the fatality rate may sometimes reach 20%.
In the 4th century B.C. Hippocrates described the disease. There are records of descriptions of diphtheria type diseases in ancient Egypt and Syria. A major epidemic swept through much of Europe during the 17th century; during this period it was referred to as the strangling angel of children because it caused the death of many children by suffocation.
Princess Alice, the second daughter of Queen Victoria (Great Britain), died of diphtheria after nursing her children who were infected. Princess Alice"s daughter, Princess May, also died of the same disease.
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In the 1920s between 100,000 and 200,000 people became infected with diphtheria each year in the USA, causing up to 15,000 deaths annually. Most of the infections and fatalities were among children. A serious outbreak in Nome, Alaska, in 1925 resulted in the Serum run to Nome to deliver diphtheria antitoxin. It is now celebrated by the Great Race of Mercy. 20 mushers, along with approximately 150 sled dogs travelled 674 miles across Alaska in five and a half days. This feat saved the people of Nome from an emerging and potentially devastating epidemic.
Between the years 2000 and 2007 there were only 5 reported cases of diphtheria in the whole of the USA. The DPT (diphtheria/pertissis/tetanus) vaccine is currently recommended for all children of school age. When cases are detected in developed nations it tends to be big news because it is so rare. When somebody dies it becomes an even bigger news item and authorities respond rapidly, reminding people to re-check their vaccination histories, as happened in London in 2008.
Vaccination rates in the USA tend to be lower than those in much of Western Europe. Approximately 77% of American children aged between 19 and 35 months in 2006, and 94% of UK children by the time they reached the age of 2 were vaccinated against diphtheria.
Diphtheria outbreaks are very uncommon today, but they still occur, and can even strike in relatively developed nations if vaccination programs are not maintained. During the late 1980s vaccination rates in the former Soviet Union areas dropped dramatically. This led to a serious outbreak which infected approximately 2,000 people in 1991, and according to Red Cross estimates reached 200,000 cases and 5,000 deaths by 1998. The Guinness Book of Records cites this specific outbreak as "the most resurgent disease" (a disease that was apparently eradicated, but then came back).
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According to the World Health Organization (WHO) there were 4,190 reported cases of diphtheria worldwide in 2007. WHO estimates that 5,000 people died of the disease in 2002. It is very difficult to get accurate worldwide figures because global data has to rely on reported cases and estimated deaths - in many parts of the world, especially in very poor and remote areas, the number of real and reported cases may vary substantially. An interesting article that was published in The Lancet, a medical journal, found that many official country reports and WHO/UNICEF estimates vary considerably from what is actually really happening.
What Causes Diphtheria
Diphtheria is caused by a pathogenic (disease causing) bacterium Corynebacterium diphtheriae (C. diphtheriae). This bacterium multiplies rapidly spreading through the upper respiratory tract where it causes inflammation. In more serious cases C. diphtheriae produces a toxin which can enter the blood stream to involve the heart, brain and nerves.
It is a contagious disease that can be contracted by:
*Inhaling the aerosolized secretions of an infected person - air-borne droplets expelled from the body. Sneezing and coughing are the most frequent ways the infection is spread.
*Direct contact with the secretions from the nose and throat of an infected person.
*Direct contact with a skin ulcer of an infected person.
*Possibly, but very rarely, through contaminated personal or household items.
Risk Factors
Diphtheria is more apparent in:
*Crowded, unsanitary environments.
*People who don"t have immunity against the disease (vaccination.)
*Undernourished individuals.
*Epidemic areas.
What are The Symptoms of Diphtheria?
Diphtheria has an incubation period of 2-5 days (symptoms will show 2-5 days after the bacteria infect a person), and in some cases up to 10 days. Onset is slow, after which the disease develops rapidly.
Signs and symptoms are :
*Sore throat.
*Difficulty breathing.
*Swollen neck glands.
*Nasal discharge.
*Pain when swallowing.
*Weakness.
*High temperature (fever).
*Gray membrane covering the throat.
*Pallor (skin is pale).
*Listlessness.
*Fast heart rate.
*Hypotension (low blood pressure).
*Bull neck - in about 10% of cases the neck will become very bloated; this is informally referred to as bull neck. There is a higher risk of death when this occurs.
Children will more commonly have nausea, vomiting, chills and a high fever. However, some children will show no symptoms until the infection is more advanced.
How is diphtheria diagnosed?
Diphtheria is suspected when individuals show the distinctive signs and symptoms, such as the grey membrane covering the throat and a sore throat.
The diagnosis of diphtheria is confirmed by taking a sample of tissue (swab) from the inside of the throat. An examination of the swab under a microscope will detect the presence of C. diphtheriae.
Doctors who suspect diphtheria do not usually wait for the lab results to come back before starting treatment. The risk of complications is too high. Treatment will usually begin immediately.
How is diphtheria treated?
In North America, Europe, and many other countries the patient will be hospitalized in an isolation ward to prevent the infection spreading. Infected patients will only be allowed to leave when tests show they are completely free of infection.
Diphtheria is treated with two types of medication.
*Antibiotics that kill bacteria and clear up the infection. A course will last 14 days. Antibiotic treatment is usually with penicillins or macrolides.
*Antitoxins that neutralize the diphtheria toxin. A course will last 3 days.
Additionally if the patient experiences trouble breathing doctors will surgically remove part of the gray membrane covering the throat.
Doctors may also to decide to place the patient on a ventilator. Another measure may include intubation - a breathing tube is inserted into the patient.
Close contacts - anybody who had been in close contact with the infected patient will need to be tested for infection. This will include household members, family, close friends, and sexual partners. The doctor will test them for signs and symptoms of the disease, and take throat swabs (for seven days). If necessary, they will be prescribed antibiotics and administered a booster vaccine. Experts say that the risk of infection for work colleagues and classmates is very low.
Prevention of diphtheria
The best way to prevent becoming infected is to keep up-to-date with your shots (vaccinations). It is advisable to take a booster jab when travelling to areas where diphtheria is endemic.
What are the complications of diphtheria?
*Respiratory failure
A combination of factors can lead to respiratory failure.
*The membrane that forms at the back of the throat can cause breathing difficulties.
*Tiny particles of the membrane can end up in the lungs, resulting in extensive inflammation of the lungs.
*The bacterium produces a toxin that can damage the lungs
Respiratory failure means the loss of much or all of normal lung function. The risk is higher if the patient receives no treatment, the disease had progressed before treatment started, or if the patient has a weakened immune system.
*Myocarditis (inflammation of the heart muscles)
C. diphtheriae produces a toxin that can cause inflammation of the heart muscle. Myocarditis often results in an irregular heartbeat, which in turn raises the risk of a blood clot or stroke. Myocarditis can lead to heart failure - when the heart cannot pump blood around the body properly.
*Pneumonia
If the patient has swallowing difficulties he/she is more likely to swallow food or drink "down the wrong way" - into the lungs instead of into the digestive system. The food or drink that gets into the lung can become infected, which may result in pneumonia (aspiration pneumonia).
*Kidney failure
This can be either a consequence of heart failure, which is a possible complication of diphtheria, or as a direct result of the toxin produced by the C. diphtheriae bacterium.
*Paralysis
Diphtheria can cause paralysis in the neck, throat, respiratory muscle, and the eye.
Written by Joseph Nordqvist
Edited by Christian Nordqvist
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today