[Atypical Mycobacterias in Mexico. Incidence and epidemiology in a general hospital].

All the cultures for mycobacteriae taken from 1967 to 1973 at the Hospital General del Centro Médico Nacional del Instituto Mexicano del Seguro Social were reviewed. From 802 positive cultures, 361 (44.2 per cent) were atypical mycobacteriae. 89 per cent of them were scotochromogen, 10.3 per cent of rapid growth, one non-chromogen, and none were photochromogen. These data are in contrast with those observed in other countries. Isolation sources varied also from other reports, in this series the most common isolation were from urine specimens, sputum, feces and bone marrow. A possible explanation for that in this hospital there are very few pulmonary patients. The percentage of atypical mycobacteriae was greatest in the last two years. In bacterioscopic examination atypical micobacteriae were detected less frequently than M. tuberculosis.