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To investigate the transmission of SARS-CoV-2 via blood, we conducted retrospective molecular screening in blood donated during the first pandemic peak in the two French regions with the highest community transmission.Archived plasma samples randomly selected from donations collected between March 23 and 29, 2020, in Eastern and Northern regions of France were tested for SARS-CoV-2 RNA in minipools of 4 donations (MP4) using the Grifols ProcleixSARS-CoV-2 assay. Reactive MP4 and the four corresponding plasmas were further tested with alternative RT-PCRs and sequencing. Testing for SARS-CoV-2 antibodies and in vitro infectivity in cell culture were also performed.Among the 2818 MP4 (corresponding to 9672 donations) tested for viral RNA, 5 were weakly reactive. Among the 20 plasmas included in these five MP4, one presented low-level reactivity with RT-PCRs and Procleix SARS-CoV-2 and was confirmed on sequencing. The estimated prevalence was 1.03/10,000 (95% CI 0-3.1). The 20 plasmas were antibody nonreactive and none of them showed cytopathic effects in cell culture. When recalled, the index-donor declared having had symptoms compatible with SARS-CoV-2 infection a few days after donation. The two immunocompromised recipients transfused with red blood cells and an inactivated pooled platelet product did not develop COVID-19.Our results indicated a low prevalence of SARS-CoV-2 RNA in the plasma of asymptomatic blood donors during the pandemic peak and no evidence of infectivity in vivo and in vitro. The transfusion risk remains theoretical and does not justify the implementation of SARS-CoV-2 NAT for blood donations.

International audience

BACKGROUND The transfusion of platelet concentrates (PCs) contaminated with bacteria may cause serious, and even fatal, septic reactions in patients. The aim of this study was to compare the VersaTREK with the BACTEC FX automated culture systems for screening bacterial contamination, directly after the delay of 24 hours of preparation to obtain the final pooled buffy coat PCs, to prevent transfusion-transmitted bacterial infections. STUDY DESIGN AND METHODS Seven bacterial strains were each inoculated into five replicate pooled buffy coat PCs at approximately 100 colony-forming units/unit, and 5- or 10-mL samples were inoculated into duplicate aerobic culture bottles. The time and detection rates were compared between BACTEC FX, as a reference method, and VersaTREK. RESULTS Time to detection was significantly shorter using VersaTREK for most species detected by both systems for the volumes tested. Of 70 VersaTREK cultures, 69 (98.57% detection rate) were positive after 24 hours of incubation with the 5-mL sample. In contrast, the BACTEC FX system detected all positive samples in PCs for the volume of 10 mL, although seven samples were false negatives for the 5-mL volume. CONCLUSION The VersaTREK system compared favorably to the BACTEC FX system for 5-mL volumes (p < 0.05) and could be considered a potential method for detecting bacterial contamination in PC samples directly after 24 hours of preparation of the final pooled buffy coat PCs.

International audience; A fraction of plasma donations undergoes hepatitis E virus (HEV) RNA screening since late 2014 in France. The aim of this study was to determine the frequency of HEV RNA as well as the viral load and the evolution of genotype distribution over a 3-year period (2015-2017) in asymptomatic blood donors in comparison with symptomatic patients routinely diagnosed. The overall detection rate of HEV RNA in plasma donations was 0.10% during the 3-year period, with a median viral load of 717 IU/mL (range

International audience

The aim of this study was to assess the seroprevalence, viremia, genotype distribution, and demographic history of hepatitis C virus (HCV) in the Republic of the Congo. Testing was carried out on sera samples collected in 2005 from 807 Bantus belonging to the Kongo, Teke, and Ngala subgroups and 80 Pygmies. Positive HCV serology was found in 50 (5.6%) individuals including31 (60%) who were viremic. Seroprevalence increased with age with a cutoff at 50 years:2.8% 50. Twenty-one strains belonged to four described subtypes, that is, 4c in eight cases, 4h in two, 4k in three, and 4r in eight. Ten strains could not be assigned to any known subtype and may represent six new variants, that is, subtype 4 in five cases and subtype 2 in one. Evolutionary analysis of subtype 4c and 4r sequences indicated a period of enhanced transmission in the mid-twentieth century probably due to iatrogenic causes. This study underlines the high genetic diversity of strains in the Republic of the Congo with nine subtypes 4 and one subtype 2.

BACKGROUND: The operational and analytical performance of two automated triplex hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) nucleic acid test (NAT) systems were compared in four screening laboratories of the French Blood Service. STUDY DESIGN AND METHODS: Two laboratories evaluated the Procleix Tigris system (Chiron/Gen-Probe) in individual donation (ID) format and two sites used the cobas s 201 system (Roche Molecular Systems) on minipools (MPs) of six donations. The analytical sensitivity, the specificity, and operational performance were compared. RESULTS: The ID to MP-NAT relative sensitivity factors in standard dilution panels of different genotypes varied between 8.7 and 21.9 for HCV RNA, 6.7 and 14.8 for HIV RNA, and 0.71 and 11.6 for HBV DNA. Tigris was 800-fold more sensitive than cobas s 201 (1:6) for a HIV group O sample, but did not detect the HIV-2 sample picked up by cobas s 201 with equal sensitivity as the HIV-1 group M samples. The specificity of both NAT systems after initial screening of 10,520 donations with Tigris and 1444 test pools on s 201 was 99.9 percent for both systems, but reached 100 percent after the repeat and pool resolution test algorithms. A higher throughput of the pool test protocol on cobas s 201 became apparent when the daily workload was more than 400 donations. CONCLUSIONS: Tigris ID-NAT format was significantly more sensitive than cobas s 201 MP-NAT in detecting HCV RNA and HIV RNA dilution panels, but despite the 1:6 dilution factor in s 201 the difference in sensitivity was not significant for some of the HBV genotype panels. Both NAT systems demonstrated acceptable operational performance, but for routine use further improvement in system reliability is desirable.

TTV and TTMV (recently assigned to the floating genus Anellovirus) infect human populations (including healthy individuals) at high prevalence (>80%). They display notably high levels of genetic diversity, but very little is known regarding the distribution of Anellovirus genetic groups in human populations. We analyzed the distribution of the major genetic groups of TTV and TTMV in healthy voluntary blood donors using group-independent and group-specific PCR amplifications systems, combined with sequence determination and phylogenetic analysis. Analysis of Anellovirus groups revealed a non-random pattern of group distribution with a predominant prevalence of TTV phylogenetic groups 1, 3, and 5, and of TTMV group 1. Multiple co-infections were observed. In addition, TTMV sequences exhibiting a high genetic divergence with reference sequences were identified. This study provided the first picture of the genetic distribution of the major phylogenetic groups of members of the genus Anellovirus in a cohort of French voluntary blood donors. Obtaining such data from a reference population comprising healthy individuals was an essential step that will allow the subsequent comparative analysis of cohorts including patients with well-characterized diseases, in order to identify any possible relationship between Anellovirus infection and human diseases.

TT virus-like minivirus (TLMV) was recently discovered as a human circovirus. Little is known about its natural history and molecular epidemiology. A study of TLMV infection is described in a population of French hemodialysis patients. TLMV DNA was tested by seminested PCR system located in the noncoding region in 81 patients divided into seven groups according to the origin of their renal disease. Quantitation of TLMV DNA in serum was carried out. Sequences from 28 patients were compared with 40 sequences retrieved from databases and 53 TLMV sequences cloned from the serum of a single patient. The prevalence of TLMV DNA in hemodialysis patients was 95.1%. In this study, 24 samples (29.6%) presented viral loads of > 125 equivalents of plasmid (Ep)/ml, and only 6 (7.8%) had viral loads of > 125 × 102 Ep/ml. A significant correlation (P 125 × 102 Ep/ml and the neoplastic origin of end-stage renal disease. Analysis of 53 sequences cloned from a single individual demonstrated high sequence variability, as shown by the genetic distance of 40.2%. This genetic distance is comparable to that between the most divergent sequences of TLMV reported to date (43.5%). These data suggest that TLMV viral load is possibly related to the level of immunocompetence of hemodialysis patients; the genetic diversity of TLMV is extremely high; and co-infection by different strains is possible. J. Med. Virol. 67:630–635, 2002. © 2002 Wiley-Liss, Inc.

BACKGROUND: The purpose of the study was to analyze serologic and molecular markers of the GB virus type C/hepatitis G virus (GBV-C/HGV) infection in voluntary blood donors from Southeastern France. STUDY DESIGN AND METHODS: Sera were tested for the presence of GBV-C/HGV RNA by reverse transcriptase-polymerase chain reaction and that of antibodies to the GBV-C/HGV E2 (anti-E2) antigen by an enzyme-linked immunosorbent assay. A first cohort (1660 blood donors) was tested prospectively and a second cohort (238 samples with hepatitis markers) was tested retrospectively. Donors in the prospective study were questioned for possible risk factors of virus transmission. Amplification products were sequenced and subjected to phylogenetic analysis. RESULTS: Approximately 2.6 percent of individuals accepted for blood donation and 15.4 percent with positive hepatitis C virus serologic tests carried GBV-C/HGV RNA. Anti-E2 was detected in these two populations in approximately 12 percent and 48 percent of donors, respectively. Moderate relative risks were found only in tattooed or pierced individuals (1.82) and health care workers (2.45). Almost all strains were located in the same phylogenetic branch as HGV Group 2. CONCLUSION: Though a large proportion of the donors tested have been in contact with GBV-C/HGV, no elevated relative risk of infection was identified. The phylogenetic distribution of viral strains suggests that the infection is endemic in this population.

The risk of malaria transmission by blood transfusion is critical due to extensive travel from endemic areas to non-endemic areas. An enzyme-linked immunosorbent assay (ELISA) malaria antibody test has been developed that is claimed to perform better than the immunofluorescence assay test (IFAT). The assay contains antigens to both Plasmodium falciparum and Plasmodium vivax. A multicentre study was performed to evaluate the appropriateness of replacing the IFAT by the new ELISA test. Nine French blood banks participated in this multicentre study. Two panels of samples were evaluated. The first included 4163 samples from healthy donors and was used to calculate clinical specificity of the assay. The second involved 10 995 samples either collected retrospectively or prospectively from malaria-risk donors was used to assess the comparative performance of the ELISA and IFAT. Discordant samples were further tested using an in-house IFAT and also tested for presence of Plasmodium DNA by polymerase chain reaction. The ELISA showed a clinical specificity of 99.02%. In the malaria-risk blood donors groups the retrospective group showed a concordance rate of 92.6% (k = 0.90) while the prospective group showed a concordance rate of 97% (k = 0.46). After confirming the discordant sample results by an in-house IFAT the k index increased to 0.81. None of the discordant samples was shown to contain Plasmodium DNA. The performance of the ELISA test in this study has confirmed its potential as a new screening test for use in blood banks as an alternative to the IFAT in prevention of transfusion-transmitted malaria in non-endemic countries. (authors)