Subclinical infection with mycobacteria in southern Iran.

In 50 non-tuberculous adult patients hospitalized in the Pahlavi University Medical Center skin testing with 5 tuberculin units of purified protein derivative of mammalian Mycobacterium tuberculosis (PPD-M) and equivalent amounts of antigen from Mycobacterium kansasii (PPD-Y) and Mycobacterium Gause (PPD-G), as well as 0.1 ml mumps antigen was carried out. Thirty four per cent, 26 per cent and 12 per cent of the patients had induration greater than 10 mm in diameter to PPD-M, PPD-Y and PPD-G respectively. However, only 28 per cent, 8 per cent and 2 per cent had induration to the above antigens which was greater than 10 mm in diameter and in which the induration was greater than that produced by the other mycobacterial antigens tested. Thirty per cent of the patients had positive reactions to mumps antigen. The results indicate that subclinical infection with Mycobacterium tuberculosis is relatively common, that infection with atypical mycobacteria may occur and that the incidence of mumps skin reactivity is low in this part of the world.