[Mycobacterial infections in HIV-infected patients in Cali, Colombia]

Abstract

The prevalence of mycobacterial infections was determined in a sample of 155 individuals infected with human immunodeficiency virus (HIV) who were treated in the Social Security Institute (SSI) of Cali, Colombia. A tuberculin test (2 TU PPD RT23) was used, and the presence of mycobacteria was checked through direct microscopy and culturing blood, urine, feces, and gastric aspirate. When clinically indicated, samples of cerebrospinal fluid, bone marrow, and sputum were also examined and cultivated. The absence of reactivity to tuberculin was significantly more frequent in the patients than in the controls (91.3%, compared to 57.4%; chi 2 = 33, P = 0). The prevalence of tuberculosis was 6.5%, in comparison with 0.04% among a group of HIV-negative ISS members (exact binomial 95% confidence interval: 0.0313% to 0.1154%). Nontuberculous mycobacteria (NTM), present in 43 patients, were significantly more frequent than Mycobacterium tuberculosis (27.7%, versus 6.5%; chi 2 = 24.78, P = 0.000,001), but they caused illness only in some cases. The most common species were those of the M. avium-intracellulare complex. M. avium-intracellulare and M. fortuitum had a total prevalence of 7.1% and were the most-prevalent NTM that caused disease in these patients (4.5%); they were also responsible for three cases of disseminated infection. Clinical disease caused by M. tuberculosis or NTM and complete tuberculin anergy were associated with stage-IV HIV infection and with CD4 lymphocyte counts < or = 400/microL. However, the lack of immunocellular response, shown by limited tuberculin reactivity, was found beginning with the asymptomatic HIV carrier stage. The progressive deterioration of the immune system of HIV-positive patients is the determining factor in the high morbidity and mortality with mycobacteria infections and requires prompt chemoprophylaxis or treatment.