Prevalence of nonspecific tuberculin sensitivity in certain parts of India.

A survey was carried out in certain parts of India to determine the prevalence of nonspecific tuberculin sensitivity. In the temperate zone, villages situated 1 200 m or more above mean sea level showed a markedly lower prevalence than villages in the plains did. In the tropical zone, the prevalence of nonspecific sensitivity was high. The prevalence of infection due to Mycobacterium tuberculosis was much lower than that of nonspecific sensitivity and the rates did not vary greatly in the areas surveyed.