Anti-Toxic Immunity to Diphtheria among a Group of Indians in Nainital District, U. P., India, as Evidenced by the Schick Tests

Diphtheria as an epidemic disease is comparatively infrequent in tropical countries. There is evidence, however, that the disease is endemic in India and in other equatorial zones. From studies made in a number of countries, the epidemiology of the disease has become more easily understood than before. Certain features may, therefore, be now fitted into the epidemiological conception of this and other similar diseases. For example, it is known that diphtheria is more concentrated among children under four years of age in tropical than in temperate countries. Thus Doull (1928) gives the proportions of deaths in the 0-4 years age group to the total at all ages