In the August Ministry, a classification of immunization practices was cited which stated that the "must-be-done" group included immunization against smallpox and diphtheria. A discussion concerning the necessity of obtaining protection against smallpox was included. This month we shall direct our attention to the prevention of diphtheria.
1. The Must-Be-Done Group—Diphtheria
Diphtheria is primarily a disease of young children. Approximately ninety-five per cent of cases diagnosed as diphtheria occur in children less than six years of age. "Two thirds or more of the urban cases are in children under ten years of age, and two thirds or more of the urban deaths occur in children under five years of age."'
If the damaging results of the disease are to be eradicated, health educators must direct their attention to informing parents of infants and preschool children of the importance of securing such protection for their children. How old should the child be before he is immunized against diphtheria ? A newborn child of a mother who has developed an immunity to the disease will have received through the placental circulation enough antibodies to protect him for a few weeks or months. Breast feeding may assist somewhat in this protection. By the ninth month of life this passive congenital immunity has been lost in a high percentage of infants.
"All children should be immunized against diphtheria. The following procedure is recommended:
At six to nine months of age either two doses of diphtheria toxoid, alum precipitated, or three doses of fluid diphtheria toxoid, at one-month intervals. This same procedure should be applied to all children at or below six years of age if immunization has been neglected in infancy. Children given an immunizing treatment during infancy should receive a single reinforcing dose on entrance to school."
Parents should seek to discover whether the child has been protected by the immunizing treatment by having a Schick test administered approximately three months after the immunizing treatment. The Schick test is the injection, intradermally, of the diluted toxin into the flexor surface of the forearm. By noting the reaction to the test, a physician may determine whether there is diphtheria antitoxin in the blood, and thus tell whether the individual is susceptible or immune to diphtheria.
It has been pointed out that diphtheria is primarily a disease of the preschool child and the elementary-school child in the lower grades. The reason for this is that an adult tends to develop an immunity to the disease, as he frequently "has received many small doses of diphtheria bacilli, no one of which was sufficient to cause the disease. The tissues of this person, however, have reacted to the stimulus of these doses, or rather to that of the toxin which they produced, by producing chemical antidotes known as antibodies (because they are "anti," or against, the toxin) which stand ready to combat any new dosage which the patient may receive."3
Because of the extreme susceptibility of preschool children, they are usually given the immunizing treatment without a Schick test's having been previously administered. On the other hand, among children of school age who have not been immunized, a certain portion have naturally become immune. For this reason, these children are usually given a Schick test to determine their immunity and their need of the preventive treatment.
Teachers, nurses, physicians, and other adults likely to be frequently exposed should be given a Schick test periodically and actively immunized if the Schick test is positive. No life should be lost today from diphtheria, and furthermore no child should suffer from the disease. Science has provided the preventive measures which make this possible. Some cities have carried on such an extensive preventive program that in as long a period as five years no deaths from diphtheria have occurred.
If as high as sixty per cent of the children are immunized, the disease will disappear in epidemic proportions. Even if one hundred per cent of the children were immunized, we would need to continue to immunize children of each succeeding generation. The reason for this is that a small per cent of the population are known to be carriers of the diphtheria bacillus ; namely, healthy individuals harboring virulent forms of the germ in the mouth, throat, and nose. Such persons do not develop symptoms of diphtheria on account of their natural immunity or resistance to the diphtheria germ, but they can transmit the organism to others. When exposure occurs, if it is known in time, the disease may still be prevented, or the severity of it abated, by the administration of a suitable dose of antitoxin.
It is extremely important that when the disease is contracted, antitoxin be given as early as possible. Each hour the administration of antitoxin is delayed, the dangers from the disease and the possibility of death increase. "This, of course, is a passive immunization, and since the material injected is horse serum and really foreign to the human body, it is rapidly eliminated, so that the immunity lasts for only a short time. The prophylactic use of antitoxin in this way is now rarely necessary?' The protection is probably entirely lost by the end of the third week. Following such an experience, parents should seek to have their children immunized if they have not developed an immunity. An attack of the disease does not necessarily ensure immunity against it.
Milk can be infected by carriers of the diphtheria bacillus. Milk is a good culture medium for the disease organism, and may cause wide dissemination of the disease. Diphtheria carriers, or persons in contact with an individual ill from the disease, should be barred from handling food. Pasteurization of all milk ensures the destruction of any diphtheria bacilli which may have been conveyed into it.
Since every means necessary for the prevention of the disease is available, every preschool and elementary-school child should be protected against diphtheria. Economically this protection is within the reach of all. An eminent physician has said that if a death due to diphtheria occurs, it is murder chargeable to someone's neglect. This is a strong statement ; but how else can we view the matter when not only the death, but the disease itself, could have been prevented if proper protection had been secured at the appropriate time?
Diphtheria cases and deaths are more frequent in the fall and winter months than in other seasons of the year. Parents should seek to protect their children against this disease now. (Concluded in December)
1 Committee of the American Public Health Association, "The Control of Communicable Diseases," p. ii. Public Health Reports, Reprint No. 1697, Washington, D. C.: United States Government Printing Office, 1940.
2 1d., p.12
3 Stimson, A. M., "The Communicable Diseases," p. 21, Miscellaneous Publication Number 30, Washington, D. C.: United States Printing Office, 1939. 4Surdon, Kenneth L., "A Textbook of Microbiology," p. 410. New York City : Macmillan, 1939.