Analysis of transmitted drug resistance and HIV-1 subtypes using dried serum spots of recently HIV-infected individuals in 2013 in Germany

INTRODUCTION The Robert Koch Institute (RKI) aimed to assess a molecular surveillance strategy based on filter-dried serum spots (DSS) of all newly diagnosed HIV infections in Germany. In 2013, diagnostic laboratories sent DSS to the RKI representing 55% of the newly diagnosed HIV infections reported to the RKI (protection against infection act). DSS were first tested serologically to identify recently acquired infections (<140 days duration of infection); those classified as "recent infection" were processed for HIV-1 genotyping. The aim of this study was to assess the level of TDR and the current HIV-1 subtypes in the main HIV transmission group categories (TrGrpC) in 2013: men who have sex with men (MSM), women/men with heterosexual contacts (HET) and injecting drug users (IDUs). MATERIALS AND METHODS DSS were tested for recency of infection using the BED capture EIA. Viral RNA from "recent infections" was amplified by HIV-1 group M generic pol-RT-PCR covering all resistance-associated positions in the HIV-1 protease (AS1-99) and reverse transcriptase (AS1-252) if viral loads were ≥6,500 copies/mL. PCR amplicons were sequenced (Sanger) to analyze genotypic resistance and the HIV-1 subtype. RESULTS were merged to data from the HIV report, i.e. the TrGrpC. RESULTS In 2013, 1027 DSS were classified as recent HIV infections (506 MSM, 118 HET, 31 IDUs, 6 others, 366 unknown). RNA was extracted from 703 recent cases and 389/503 samples with sufficient viral load were PCR-positive. By June 2014, 276/389 samples were sequenced: TDR was identified in 13% (35/276) of the recent infections including single (PI, NRTI, NNRTI) and dual drug class resistant strains (NRTI/NNRTI; NNRTI/PI). 18% (51/276) of recent HIV-1 infections were caused by non-B subtypes (A1, C, CRF01_AE, CRF02_AG, D, F, G, URFs). TDR was observed at comparable levels in all TrGrpC. Proportions of non-B infections were significantly higher in HET (78%; 14/18) and IDUs (60%; 3/5) compared to MSM (8%; 14/169) (p<0.01). CONCLUSIONS The proportion of TDR was similar but the proportion of HIV-1 subtype non-B infections was higher as previously described for Germany based on results from the German HIV-1 Seroconverter Cohort (1),2. This difference could be the result of a broadened inclusion of HET and IDUs due to the sampling method used making this study representative for molecular surveillance of HIV-1 in Germany.