Drug resistance among chronic HIV-1-infected patients naïve for use of anti-retroviral therapy in Sao Paulo city.

Primary infection with drug-resistant HIV appears to be increasing in the regions where HAART is widely available, which may reduce efficacy of first-line antiretroviral therapy. To determine prevalence of antiretroviral drug-resistant mutations in newly diagnosed subjects in a clinical setting where HAART has been widely used since 1997. One hundred and thirty-six HIV-1-infected adult patients were diagnosed with HIV infection between January 2000 and December 2006 in the HIV out-clinic at the HC/FMUSP, Sao Paulo city.