Transmission of HIV drug resistance and non-B subtype distribution in the Spanish cohort of antiretroviral treatment naïve HIV-infected individuals (CoRIS).

CoRIS is an open multicentre cohort of HIV seroprevalent ARV-naïve subjects who began treatment at 32 Spanish healthcare centres from January 2004. Up to November 2008, a total of 683 FASTA format sequences, encoding the HIV protease and reverse transcriptase (RT) derived from plasma samples at entry into the cohort, had been obtained for examination of transmitted drug resistance (TDR) and HIV clade. TDR was found in 8.5% of the patients (4.4% NRTIs, 4% NNRTIs, 2.2% PIs). The most prevalent resistance mutations were: T215 revertants (3.8%), D67NG (1.3%), K219QENR (1.2%) and M41L (1%), for NRTIs; K103N (3.2%), for NNRTIs; I54VLMSAT, M46I and L90M (0.7%), for PIs. Non-B subtypes were recognized in 104 patients (15.2%) and were more common in Sub-Saharan Africans (15/17, 88.2%), Eastern Europeans (7/12, 58.3%) and Northern Africans (8/16, 50%) than among Spaniards (53/479, 11%) (p<0.001). The most prevalent non-B subtype was CRF02_AG (4.4%), followed by subtype D (1.9%), CRF03_AB (1.5%), CRF07_BC and subtype F1 (1%). A trend was observed for the transmission of non-B subtypes to increase and for TDR to decrease.