New and old complex recombinant HIV-1 strains among patients with primary infection in 1996–2006 in France: The French ANRS CO06 primo cohort study

Background Prevalence of HIV-1 non-B subtypes has increased overtime in patients diagnosed at the time of primary infection (PHI) in France. Our objective was to characterize in detail non-B strains which could not be genetically classified into the known subtypes/Circulating Recombinant Forms (CRFs).