Session 29Oral Abstract Presentations Topics in Primary HIV Infection Session Day and Time: Thursday 10 - 11 am Presentation Time: 10:30 Room: Ballroom B
153 Co/Super-infection in Recently HIV-1 Infected IVDUs L. Perrin*1, S. Yerly1, S. Jost1, M. Monnat2, A. Telenti3, J. P. Chave4, L. Kaiser1, P. Burgisser3 1Geneva Univ, Switzerland; 2Lausanne Ctr Saint-Martin, Switzerland; 3Lausanne Univ Hosp, Switzerland; and 4Lausanne La Source Hosp, Switzerland
Background: Intravenous drug users (IVDUs) have repeated exposures to HIV-1 infection. We took advantage of an outbreak of CRF-11 in IVDUs in the western part of Switzerland to search evidence of co/super-infection with B subtype, the predominant subtype in IVDUs.
Methods: In 14 recently infected (< 1 yr) IVDUs with CRF-11, we sequenced the reverse transcriptase, protease, p17 and C2V3 regions on the first available sample to determine HIV-1 subtypes using phylogenetic analyses. Specific (CRF-11 and B) nested PCR were performed in plasma and peripheral blood mononuclear cells. The first PCR was a generic amplification of a 1393 bp fragment (1419 to 2812 according to HXB2). Based on sequences of this fragment, B and CRF-11 subtype specific primers were designed for the nested PCR (1750 to 1998 according to HXB2). Subtype specific amplicons were identified on agarose gel, sequenced and phylogenetic analyses were performed.
Results: Sequences from 8/14 CRF-11 patients (pts) provide clear sequences for the 4 regions tested, whereas sequences of the 6 remaining patients provided either undetermined subtype or other subtypes than CRF-11 for at least one of the regions tested. To validate subtype specific PCR, we performed mixing experiments, using successive plasma dilutions of B and CRF-11 respectively and showed that the limit of detection of the heterologous subtypes was < 1%. Using subtype specific PCR, only the amplicon corresponding to CRF-11 was detected in 12/14 pts tested, whereas in 2 pts B and CRF-11 amplicons were recovered in their baseline samples collected 1 and 3 mos after the acute HIV-1 infection, respectively. Sequence and phylogenetic analysis of amplicons confirmed the simultaneous presence of B and CRF-11 for the 2 pts. There were 95.6% of similarity between the 2 pts's B amplicons, excluding contamination, and 100% for CRF-11 amplicons, in agreement with population sequencing results. Analysis of follow-up plasma samples in these 2 drug-naive pts confirmed the persistence of both strains for up to 2 yrs. Both strains were detected in proviral DNA in both pts at baseline and 2 yrs later for the pt with available sample.
Conclusions: In IVDUs recently infected with high-risk behavior, co/super-infection occurs relatively frequently and persists for at least 2 yrs.
