An Analysis of Tuberculous Infection From Birth to Old Age; Its Relationship to Clinical Tuberculosis and Deaths from Tuberculosis

1) Infection with tuberculosis is relatively rare in children at the present time in this community.

2) Reaction to tuberculin after childhood increases precipitously, reaching its maximum at approximately the age of 50. After 50 years of age it declines, probably due to the fact that the skin of older people is not as sensitive.

3) This study shows that in this community the tuberculin reaction is slightly more prevalent in the male up to the age of 30; after this age the male is much more often infected.

4) This increased infectivity of the male does not seem to be due to environment, but probably represents a sex characteristic.

5) After the age of 30, not only is the infected male more prone to exhibit clinical tuberculosis than the female, but the disease is still more likely to be fatal.

6) Infection in the age group 0-14, more than at any other time, results in clinical disease and death. Such consequences are less often noted in the 15-29 year group, and least after 30 years.

7) Since infection, clinical disease, and death from tuberculosis are all seen chiefly after childhood, the conclusion seems warranted that most cases of adult tuberculosis in this community result from infection beyond the age of childhood.

8) The reason that there is more clinical tuberculosis and death from tuberculosis in older ages may well be due to the fact that in the latter part of life there is more primary infection.