Mycobacterial infection in Mexican AIDS patients

To describe the characteristics of mycobacterial infection in Mexico, we reviewed records from patients who were seen at the AIDS Clinic of the National Institute of Nutrition in Mexico City from 1983 to 1992. Of 460 AIDS patients, 118 (25.6%) were found to have mycobacterial infections by positive Ziehl-Neelsen stain, culture, or both. Cultures were completed for 66 of the 118 stain-positive specimens. Mycobacterium tuberculosis was the most common species found (n = 13), followed by M. avium complex (n = 12); 21 infections were identified a nonspecific mycobacteria other than tuberculosis (MOTT) and 20 infections were from species other than tuberculosis. Susceptibility testing was performed in only two tuberculosis cases, with one strain showing multidrug resistance. We conclude that mycobacterial infection is common among our AIDS population, and MOTT may be at least as common as M. tuberculosis. Previous reports of the rarity of MOTT could be related to the lack of adequate diagnostic methods in developing countries.