Low rate of transmitted drug resistance may indicate low access to antiretroviral treatment in Maranhão State, northeast Brazil.

The Brazilian AIDS epidemic is characterized by significant geographic contrasts: a reduction in incidence and mortality in the epicenter (southeast) and an increase in the northeast. HIV-1-transmitted drug resistance (TDR) and genetic diversity were investigated among 106 antiretroviral (ARV)-naive patients from Maranhao State, northeast. The HIV-1 protease (PR) and reverse transcriptase (RT) regions were sequenced; subtypes were assigned by REGA/phylogenetic analysis. TDR to the nucleoside/nonnucleoside reverse transcriptase inhibitor (NRTI/NNRTI) and protease inhibitor (PI) was identified by the Calibrated Population Resistance tool (Stanford). The median age was 31 years (range 18-72), with 54.7% women, 78.3% heterosexual transmission, and 17.9% men who have sex with men (MSM). Around 30% had <350 CD4(+) T cells/mu l and 47.2% had plasma viral loads <= 10,000 copies/ml. The TDR rate was 3.8% (4/106; CI 95%, 1.2-8.9%) (three males, two of them MSM). Only single class mutations to NRTI (M184V; T215S) or NNRTI (K103S/N) were detected. Subtype B represented 81.1% (86/106), F1 1.9% (2/106), and C 2.8% (3/106); 14.2% were mosaics: 13 BF1 and 2 BC. Surveillance of TDR and HIV-1 genetic diversity is important to improve control strategies regionally.