Molecular epidemiology of HIV type 1 in newly diagnosed patients in southern Spain.

The prevalence of different HIV-1 subtypes in Spain varies by geographic region. In the present study isolates were collected from 72 newly diagnosed individuals in western Andalucia from 2004 to 2006. Viral sequences were amplified and the subtype diversity and prevalence of resistance mutations in the reverse transcriptase and protease genes were determined. The results presented here demonstrate that subtype B virus predominates in this region (88.9%), with the non-B subtypes CRF02_AG (9.7%) and B/G (1.4%) also present. Only two isolates (2.9%) carried resistance mutations in the reverse transcriptase gene and none of the isolates had major resistance mutations in the protease gene. Minor mutations in the protease gene were more prevalent with 86.1% of isolates containing at least one minor mutation. These results elucidate the subtype diversity present in this region and suggest that the transmission of highly resistant virus variants does not occur at a high frequency in this population.