02046nas a2200217   4500008003900000245009500039210006900134300000600203490000800209520143700217100001401654700001201668700001401680700001201694700001701706700001401723700001701737700001301754700001201767856004901779       2019                          d00aHigh multiplicity infection following transplantation of hepatitis C virus-positive organs0 aHigh multiplicity infection following transplantation of hepatit  a40 v1293 aHighly effective direct-acting antivirals against Hepatitis C virus (HCV) have created an opportunity to transplant organs from HCV-positive individuals into HCV-negative recipients, since de novo infection can be routinely cured. As this procedure is performed more widely, it becomes increasingly important to understand the biological underpinnings of virus transmission, especially the multiplicity of infection. Here, we used single genome sequencing of plasma virus in four genotype 1a HCV-positive organ donors and their seven organ recipients to assess the genetic bottleneck associated with HCV transmission following renal and cardiac transplantation. In all recipients, de novo infection was established by multiple genetically distinct viruses that reflect the full phylogenetic spectrum of replication-competent virus circulating in donor plasma. This was true in renal and cardiac transplantation and in recipients with peak viral loads ranging between 2.9 and 6.6 log10 IU/mL. The permissive transmission process characterized here contrasts sharply with sexual or injection-related transmission, which occurs less frequently per exposure and is generally associated with a stringent genetic bottleneck. These findings highlight the effectiveness of current anti-HCV regimens, while raising caution regarding the substantially higher multiplicity of infection seen in organ transplantation-associated HCV acquisition.1 aZahid, MN1 aWang, S1 aLearn, GH1 aAbt, PL1 aBlumberg, EA1 aReese, PP1 aGoldberg, DS1 aShaw, GM1 aBar, KJ  uhttps://www.notifylibrary.org/reference/5110