Childhood Diseases

As recently as the early decades of the twentieth century, childhood was fraught with diseases that often entailed suffering and premature death. Many of those diseases were highly contagious; a child who contracted one of them was immediately isolated at home and a "quarantine" sign was posted conspicuously on the door to warn others. These once-perilous diseases included diphtheria, whooping cough (pertussis), and tetanus (lockjaw), which have been effectively controlled by vaccines; scarlet fever, another such disease, is now easily treated with antibiotics.

Diphtheria is caused by a toxin-producing bacterium, Corynebacterium diphtheriae, which infects the nervous tissue, kidneys, and other organs. The disease is spread by contact with the secretions of an infected person or objects that have the bacterium on them. Diphtheria develops rapidly after a short incubation period of one to four days. The bacterium usually lodges in the tonsils, where it multiplies and begins to produce a toxin. The toxic exudate, or secretion, is lethal to the cells around the infected area and can be carried to distant organs by the blood. Areas of infection and damage can be found in the kidneys, heart muscle, and respiratory tissues as well as in the brain. A membrane that is characteristic of the infection forms over the area affected by the toxin.

If left untreated, diphtheria can cause serious heart damage that can result in death, nerve damage resulting in a palsy, or kidney damage, which is usually reversible. A penicillin treatment and a diphtheria antitoxin are used to neutralize the bacterial secretions. One of the earliest vaccines now given to children is a combined vaccine for diphtheria, pertussis, and tetanus; as a result, diphtheria is rare now.

Pertussis, or whooping cough, is another highly infectious bacterial disease so named because of the characteristic high-pitched crowing sound of the breath between coughs. The etiologic agent is the bacteriumBordetella pertussis.

Pertussis is known throughout the world. It is transmitted in the saliva of coughing patients who have the bacterium, usually in the early stages of the disease. Patients are no longer infectious after eight weeks. The bacterium invades the nose, pharynx (back of the throat), trachea (windpipe), and bronchi. Symptoms appear after an incubation period of about one to two weeks. The earliest stage of the disease consists of sneezing, fatigue, loss of appetite, and a bothersome nighttime cough. This stage lasts for about two weeks, after which the coughs become rapid (paroxysmal) and are followed by the characteristic whoop, a few normal breaths, and another paroxysm of coughing. The coughing spells expel copious amounts of a thick mucus, which may cause gagging and vomiting. This stage of the disease can last up to four weeks, after which the patient begins a recovery; the coughing lessens and the mucus decreases.

Pertussis may be fatal in very young children; it is rarely serious in older children and adults. Fatalities in young children are usually caused by a subsequent bout of pneumonia. Infected individuals should be isolated, but do not necessarily need bed rest. Very young children should be hospitalized so that mucus may be suctioned from the throat area. A pertussis vaccine is available and is part of the early inoculation program in children. It is given with the vaccines for diphtheria and tetanus. Newer "acellular" pertussis vaccines cause fewer side effects than the old whole cell vaccines.