Diphtheria is an acute contagious bacterial disease that usually affects children. For many years it was one of the most serious contagious diseases occurring in epidemic form throughout the world but because of the widespread immunization, it is now rare in most developed countries. Diphtheria usually attacks the throat and nose and in more serious cases, it can attack the heart and nerves.

Cause: Diphtheria is caused by the bacterium Corynebacterium diphtheria. The bacterium produces an exotoxin (poisonous substance secreted by a microorganism) that is carried in the bloodstream. Although the bacteria may enter the body through the skin, genitals, eyes, or ears, the most common site of infection is the upper respiratory tract. Sometimes a person may be infected by the bacteria without developing any recognizable symptoms, and he may spread the disease without knowing it. People get diphtheria by breathing in diphtheria bacteria after an infected person has coughed or sneezed, they may also get it from close contact with discharges from an infected person's mouth, throat, or skin.

Symptoms: The onset of symptoms occurs usually after an incubation period that ranges from 2 to 4 days. The symptoms includes; Moderate fever (usually less than 102°F or 38°C), chills, feeling of discomfort, mild sore throat accompanied by a brassy cough. At this time, the mucous membrane lining the upper respiratory tract becomes coated with a layer made largely of dead cells and bacteria.

Antitoxin: When the body detects the presence of diphtheria exotoxin, the body produces a neutralizing substance known as diphtheria antitoxin. If the antitoxin is produced immediately and in large enough amounts, it will enable the patient to recover from the disease. The antitoxin also provides immunity to the disease for at least several months and usually longer.

Complications: If diphtheria is not treated right away the exotoxin can sometimes impairs the functioning of the heart muscles and cause heart failure or paralyze the breathing muscles. The membrane that forms over the tonsils can also move deeper into the throat and block the airway. These complications usually arise 2 to 4 weeks after the onset of the disease.

Treatment:

• The only effective treatment of diphtheria is the prompt administration of antitoxin to neutralize any exotoxin still circulating in the bloodstream. The administration of antibiotics, such as penicillin and streptomycin, has not proved to be of any value in treating diphtheria.
• General supportive measures, such as bed rest and increasing the patients' intake of fluids are helpful in making the patient comfortable.
• Guava tea is excellent in dissolving dried mucus and killing bacteria in the respiratory tract.

Prevention: The only method of preventing diphtheria is to immunize susceptible people. The substance used in immunizing an individual is diphtheria toxoid (toxoid is a weaker form of toxin that is used in vaccine to protect people and animals from contracting the actual disease). The immunity that results from administering diphtheria toxoid lasts for at least several months and usually longer. It is common practice to administer the toxoid to children before the age of 1. At present the diphtheria vaccine is usually given in a combination shot with tetanus and pertussis vaccines, known as DTP vaccine. A child should have received four DTP shots by 18 months of age, with a booster shot at age 4 years to 6 years. After that, diphtheria and tetanus boosters should be given every 10 years to provide continued protection.

Because a person may have had diphtheria without knowing it, the only way to determine if he has had the disease is to test his immunity to it. The most widely used test for determining a person's state of immunity to diphtheria is the Schick test. In this test, a small amount of diphtheria exotoxin is introduced into the skin. If the area becomes reddish over a period of 3 to 4 days, the person is susceptible to diphtheria. If no reaction occurs, the level of antitoxin in the person's blood is high enough to protect against the disease.