DIPHTHERIA

Diphtheria is an acute infectious disease caused by Corynebac-terium diphtheriae.The microorganism produces an exotoxin which is responsible for the resulting pathologic process. The disease is characterized clinically by a sore throat and a membrane which may cover the tonsils, pharynx and larynx.

Epidemiologic factors.The highest seasonal incidence occurs during the autumn and winter months.

Diphtheria is acquired by contact with either a case or carrier, the microorganisms being disseminated by the acts of coughing, sneezing or talking.

Pathogenesis and Pathology.Virulent diphtheria bacilli lodge in the nasopharynx of a susceptible individual. Bacterial growth taking place in the secretions and epithelial debris, a toxin is elaborated and absorbed by the local mucous membrane. The toxic effect on the cells causes tissue necrosis. In addition to the necrosis, an inflammatory and exudative reaction is also induced by the toxin. The necrotic epithelial cells, leucocytes, red cells, ftorinous material, diphtheria bacilli, and other bacterial inhabitants of the nasopharynx — all these elements combine to form the typical "membrane". It sloughs off during the recovery period.

Clinical Manifestations.Diphtheria develops after a short incubation period of 2 to 4 days.

For clinical purposes it is convenient to classify the disease in accordance with the anatomic location of the membrane. The following types of diphtheria may occur: (1) tonsillar (faucial), (2) laryngeal or laryngotracheal, (3) nasal and 4) nonrespiratory types including skin wounds, conjunctival and genital lesions.

Diagnosis.An early diagnosis of diphtheria is essential because delay of administration of antitoxin may impose a serious risk on the patient. The diagnosis of diphtheria must be made clinically.

The bacteriologic confirmation by means of culture is of the greatest importance. The method of accelerated bacteriological diagnosis when the material secured with the aid of a specially prepared moist tampon is placed in a thermostat for 4—6 hours should be more widely employed. A tellurium test has been recently employed as a method of rapid diphtheria diagnosis.

Treatment.It is necessary to isolate the patient at once. Diphtheria antitoxin must be given promptly and in adequate dosage. In severe toxic forms of diphtheria it is advisable in addition to the serum to administer intravenously a hypertonic glucose solution, give the patients vitamins in the form of nicotinic acid and ascorbic acid for a period of 2—3 weeks, some. authors recommending administration of atrychnine from the 1-st days of the disease. Bed rest is very important. Other supportive measures include maintenance of hydration, a high caloric liquid or soft diet rich in vitamins, aspirin or codeine for sore throat and malaise. The patient must gargle his throat several times a day with a 2% boric acid solution. The patient's room must be aired.

Patients with laryngeal diphtheria require special treatment. In very advanced cases with severe symptoms of growing asphyxia, if there is increasing restlessness, irritability and anxiety, associated with progressive respiratory distress, a tracheotomy is indicated for the relief of obstruction. It should be performed before the child becomes cyanotic and exhausted.

Prognosis and Complications,in spite of the low fatality rate sudden death may be caused by a variety of unpredictable events, such as (1) the sudden complete obstruction of the airway by a detached piece of membrane, (2) the development of myocarditis and heart failure, and (3) the late occurrence of the respiratory paralysis due to phrenic nerve involvement. Patients surviving following myocarditis and neuritis, the recovery is a rule.

Immunity.For determining immune status the Shick test is useful. Active immunity may be induced by either an attack of diphtheria or more commonly to-day by inoculations of diphtheria \ toxoid. Immunity following an attack of diphtheria may be either j, permanent or temporary; recurrent attacks of the disease are not \ unusual. The widespread and routine immunization of infants and

children having had a profound effect on the immune status of the population at large, the incidence of diphtheria among inoculated children is lower, and the disease runs a milder course.