RESUMO
INTRODUCTION: Therapeutic measures have been successful in increasing survival rates and quality of life of HIV/AIDS-infected people. However, some people fail to respond to antiretroviral therapy (HAART) because of viral resistance-associated mutations. OBJECTIVE: To identify virus genotype and the presence of mutations that alter the susceptibility to HAART, and factors associated with the occurrence of these mutations. METHOD: A cross-sectional study was conducted on adults living with HIV attending a specialized outpatient clinic in southern Santa Catarina, Brazil. The participants were interviewed and had blood samples collected for analysis. Those with detectable viral load were genotyped. RESULTS: Out of the 629 patients recruited, 127 subjects were included due to having a detectable viral load. The most common mutations were M184V and K103N. HIV-1 subtype C was the most prevalent strain. Resistance to HAART was associated with modification in the treatment regimen (p <0.001). CONCLUSION: This study concluded that the circulating subtype virus was subtype C and that the mutations K103N and M184V were the most prevalent strains in southern Santa Catarina, Brazil.