Diphtheria, << dihf THIHR ee uh or dihp THIHR ee uh, >> is a severe, contagious infection of the upper respiratory system or the skin. It can involve serious—or even fatal—complications. During the late 1800’s, diphtheria epidemics swept the United States and Europe. At that time, most victims were under 10 years of age. Today, diphtheria affects children and adults about equally. Widespread immunization with diphtheria vaccines has reduced the number of cases of diphtheria. The vaccines first came into use about 1920.
Cause, symptoms, and complications.
Diphtheria is caused by a bacterium called Corynebacterium diphtheriae. This organism commonly infects the membranes of the upper breathing passages. It particularly attacks the tonsils and the pharynx (back of the mouth and the upper throat). The bacteria produce a toxin (poison). The toxin enters the blood and is carried throughout the body. Infected individuals spread the bacteria by coughing or sneezing. People called carriers may harbor the bacteria without showing any symptoms of the disease. Although carriers show no symptoms, they can spread the illness to other people.
Symptoms appear about two to five days after infection. They include a sore throat, fever, and swelling of the lymph nodes in the neck. A thick, grayish membrane forms on the surface of the tonsils and pharynx. The membrane may even extend up into the nose or down into the trachea (windpipe) and lungs. The membrane may interfere with breathing or swallowing. In severe cases, it can completely block the breathing passages. The membrane can cause death if not treated.
Diphtheria toxin can affect the heart, kidneys, and nervous system. One severe effect is heart muscle inflammation, called acute myocarditis. Myocarditis may result in permanent heart damage. In some cases, the toxin so weakens the heart that death occurs. Effects of nerve damage include temporary paralysis of muscles in the throat and eyes. Most seriously, the disease may paralyze the muscles used in breathing. Paralysis of the breathing muscles can be fatal.
Diphtheria bacteria also can infect breaks in the skin. Such infections are called wound diphtheria or cutaneous diphtheria. In most cases of wound diphtheria, a membrane does not form over the infected area. But toxins enter the bloodstream. They can produce the same complications as in the respiratory infection.
Treatment.
Physicians hospitalize diphtheria patients and give them diphtheria antitoxin. This substance neutralizes diphtheria toxin. If administered early enough, the antitoxin can minimize heart and nerve complications. If the membrane that forms in the throat blocks the breathing passages, a doctor may cut a temporary opening through the neck into the trachea. Heart failure is treated with medications. If the respiratory muscles become paralyzed, a machine called a respirator is used to maintain the patient’s breathing. Diphtheria patients also receive antibiotics. The antibiotics kill the diphtheria bacteria and help control secondary infections caused by other bacteria.
Prevention.
People can obtain immunity (protection) from diphtheria by using vaccines that contain diphtheria toxoid. This toxoid is a specially treated form of diphtheria toxin. It does not damage body tissues. Instead, it triggers the production of disease-fighting substances called antibodies. Antibodies formed in response to the toxoid will attack diphtheria toxin if it enters the bloodstream. Public health experts recommend that infants get a series of four diphtheria immunizations. A person should get a “booster” shot of diphtheria vaccine between the ages of 4 and 6, and about every 10 years thereafter. See Immunization .
