Introduction The WHO Global HIV drug resistance network (HIV-ResNet), was stablished to monitor the emergence and help to control the transmission of HIV-1 drug resistant strains. The TDR is progressively increasing over the last years in some Brazilian regions, mainly where the epidemic is concentrated. This study evaluated the trends in the prevalence of TDR mutations and dynamic of subtypes, among drug-naïve HIV-1 infected individuals from vulnerable group populations in the context of the WHO HIV-ResNet.
Methods We analysed a total of 536 HIV-1 sequences collected during 2005 to 2014, targeting drug naïve pregnant woman from four public antenatal care units and 159 recently diagnosed (<1 year) individuals identified in VCTs in all Rio de Janeiro state. The profiles of TDR mutations were evaluated using the updated WHO transmitted resistance mutation list and HIV-1 genetic diversity evaluated by phylogenetic analysis.
Results Overall, the prevalence of TDR was 12.5% (CI95%, 7.15% to 16.5%) being, 5.8% (CI95%, 2.5% to 9.15%) to the nucleoside reverse transcriptase inhibitors (NRTIs), 3% (CI95%, 0.1% to 4.85%) to non-nucleoside inhibitors (NNRTIs) and 3.7% (CI95%, 1.24% to 7.5%) to protease inhibitors (PIs). Both studied groups showed similar TDR prevalence for all drug classes. The timidine-associated mutations (TAMs) and M184V were the most prevalent TDR mutations found in RT gene, followed by K103N, T215 revertants and F77L. The M46I PI associated mutation was the more frequent, followed by V82A and L90M. HIV-1 subtype B was the most prevalent (80%), followed by F1 (7.5%), subtype C (4%) and BF recombinants (3.5%). In addition to non-B HIV-1 subtype A1, G, CRF02_AG, CRF31_BC, FC and DF recombinants, identified in 4% of genotyped samples. Significant difference was observed in the two groups, where subtype F (12%) was more prevalent in pregnant woman, while subtype C prevalent in new diagnosed subjects (5.9%).
Conclusion This work tried to study trends of HIV-1 TDR and the genetic diversity in Rio de Janeiro state, the second major HIV/AIDS epidemic in Brazil. The results demonstrated a sustained low prevalence of TDR to the PIs, recent accumulation of resistance associated to the NRTIs and reduction to NNRTIs over the years. The time trend of TDR observed, seem to reflect changes in antiretroviral therapy in Brazil over time. HIV-1 subtype B was the most prevalent in the study, but the increasing prevalence of subtype C and the identification of others non-B and recombinants infections, suggest the recent introduction and spreading of these viruses, respectively south Brazil and African countries in Rio de Janeiro.
Support: Oswaldo Cruz Foundation-IOC/FIOCRUZ, Brazilian Ministry of Health (DDAHV-CQV/MS), Pan-American Health Organization-PAHO and World Health Organization-WHO