The pattern of age-specific tuberculin hypersensitivity in two groups of South African schoolchildren

In epidemiological studies on tuberculosis we have observed a decrease in the prevalence of positive tuberculin reactions around the age of 13. This decrease was apparent in a variety of populations studied. Statistical analysis of the tuberculin testing data demonstrates the significance of the decrease in the proportion of positive reactors at age 13 and also of a reduction in size of reactions. The possibility of suppression of the delayed hypersensitivity reaction at about puberty is considered.