Diphtheria is an acute bacterial disease caused by Corynebacterium Diphtheriae. It is highly contagious and spreads in overcrowded areas. The disease is transmitted through respiratory secretions or droplets in the air. The bacteria may enter the body through the nose or mouth. They may also enter through a break in the skin and may colonise wound surfaces.
What are the symptoms?
The bacteria multiply in the throat or on the wound. They may form a membrane in the throat and over the tonsils. Other common symptoms include breathing difficulty, a husky voice, enlarged lymph glands in the neck (Bull neck), nasal drainage, low-grade fever and an increased heart rate.
Diphtheria may often have symptoms due to the toxins produced by the causative bacteria resulting in Diphtheritic myocarditis (toxic damage to the heart muscles) and neuritis (toxic damage to the peripheral nerves).
How is the condition diagnosed?
The appearance of the membrane in the throat is usually quite distinctive. A swab sample taken from the back of the throat is checked for the bacteria causing the disease. The bacteria are isolated and grown to see if they are producing the toxin.
What is the treatment?
The goal of treatment is to neutralize the effect of the toxins, eliminate further toxin production, control the local infection and prevent transmission. Penicillin is usually effective in treating diphtheria before it releases toxins into the blood. However one must neutralise the Diphtheria toxin circulating in the blood stream. This is done by giving an antitoxin in combination with the antibiotic. Rarely, a tracheostomy (a breathing tube inserted into the wind pipe by an operation) may be needed if the patient has severe breathing difficulties. A cardiac pacemaker may have to be given to the patient if there is severe slowing of the heart rate.
How can it be prevented?
Immunization is the best preventive measure. Immunization against diphtheria, whooping cough and tetanus is given by a combined vaccine - the DPT (triple) vaccine. Three doses are given at 2, 4 and 6 months of age. A booster dose is given at 1-1/2 and 5 and 8-10 years of age.