Evolution of transmitted HIV-1 with drug-resistance mutations in the absence of therapy: effects on CD4+ T-cell count and HIV-1 RNA load. - Bezemer D; de Ronde A; Prins M; Porter K; Gifford R; Pillay D; Masquelier B; Fleury H; Dabis F; Back N; Jurriaans S; van der Hoek L (Antiviral therapy, 2006)