When Mantoux published the intradermal technique, he also presented the results of a tuberculin survey among children from Paris, examined with that technique.
Tuberculin reactivity increased rapidly with age. By the age of 5 years, half of the children were already infected with M. tuberculosis. By the age of 11 years, the prevalence of infection was above 80%. At that time, there was little chance to escape infection by the time a person entered adulthood.
