The present study investigated the prevalence of HIV-1 multiple
infections in a population composed by 47 patients under
HAART failure and enrolled at the National DST/
AIDS, Program, Ministry of Health, Brazil.Detection of multiple
infections was done using a previously published RFLP assay for the
HIV-1 protease gene, which is able of distinguishing between
infections caused by a single or multiple HIV-1 subtypes. Samples with multiple
infections were cloned, and sequence data submitted to phylogenetic analysis. We were able to identify 17 HIV-1 multiple
infections out of 47 samples. Multiple
infections were mostly composed by a mixture of recombinant viruses (94%), with only one case in which
protease gene pure subtypes B and F were recovered. This is the first study that reports the prevalence of multiple
infections and intersubtype recombinants in a population undergoing
HAART in Brazil. Based on the data there was a steep increase of multiple
infections after the introduction of the combined antiretroviral
therapy in Brazil. Cases of multiple
infections may be associated with HIV-1 genetic diversity through recombination allowing for the generation of viruses showing a combination of resistance mutations.