Epidemiological basis of tuberculosis eradication. 5. Frequency of pulmonary calcifications after human and bovine infection.

In a study population comprising young adults from Denmark it was found that the tuberculosis morbidity was much lower among persons infected from bovine than from human sources. In an attempt to reveal the possible cause of this difference an analysis was made of the frequency of pulmonary calcifications in these two groups. The results of this study show that the frequency of calcifications is small, probably negligible, in the bovine-infected group as compared with that in the group infected from human sources. This observation suggests that the difference between the infections from bovine and human sources may lie in the dose-virulence of the infecting agent or in the route of infection.