A multidrug-resistant (MDR) HIV type 1 infection in a homosexual man and identified source patient.

We report a case (IC) of multidrug-resistant (MDR) HIV-1 infection in which the identification of the source patient (S) was supported by phylogenetic analysis of the pol gene and by the similarity of env sequences. HIV isolates from IC and S were characterized as non-syncytium viruses: a X4 variant (R(11) E(26)) was identified in both cases according to the V3 loop sequence. The pol mutational profile of IC included multiple protease and reverse-transcriptase inhibitor mutations similar to those in S. The lamivudine/tenofovir/tipranavir/ritonavir/enfuvirtide association was effective for IC but not for S.