Background: We have studied the incidence of tuberculosis++ disease, HIV infection and their association during a period of 6 years using samples analysed in a third level hospital laboratory.
Material and method: 21,242 samples for mycobacteria and 63,425 for HIV antibodies were analysed between 1993 and 1998. The protocol used for mycobacteria consisted of Lowenstein-Jensen, hemoculture, biochemical tests for identification and DNA probe. The diagnosis of HIV was performed using screening with mix EIA HIV 1 + 2, confirmed with Western-blot. Spearman coefficient correlation was used for study of tendency.
Results: 1,613 samples (7.5%) positive for mycobacteria from 566 patients (98 females and 428 males) aging between 31 and 40 years (46.9%) were detected. The highest incidence for tuberculosis was observed in 1995 (49.2 x 10(5) and was followed by a decreasing linear tendency. Mycobacterium tuberculosis (96%) and M. bovis (2.7%) were most frequent agents. 2,295 samples (3.6%) showed anti-HIV (406 females and 1,889 males). 54.1% of the infected patients belonged to the age interval 21 to 40 years. The highest incidence was observed in 1994 and was followed by a significant decrease (p < 0.05). The percentage of patients co-infected with tuberculosis-HIV was 39.7% with a maximum in 1995 followed by a linear decrease.
Conclusions: The incidence of both infections and co-infection was very high in the first triennium and was followed by a progressive decrease. The decrease of HIV preceded tuberculosis. The result suggest a possible epidemiological correlation between both infections.