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Absence of anti-HBc reactivity with detectable anti-HBs was observed in blood donors with occult hepatitis B virus (HBV) infection (OBI). The prevalence and mechanisms underlying this uncommon condition were investigated over time in Chinese blood donors with OBI. Isolated anti-HBs OBI status was identified from 466,911 donors from Dalian, China, and monitored in follow-up (range: 2.6-84.3 months). HBV vaccination status was documented, and infecting viral strains were characterized. Of 451 confirmed OBIs (1:1035), 43 (9.5%; 1:10,858) had isolated anti-HBs as only serological marker. Isolated anti-HBs OBIs differed from anti-HBc-reactive OBIs by significantly younger age (median 24 years), higher HBV DNA (median: 20 IU/ml) and anti-HBs (median 60.5 IU/L) levels, paucity of mutations in HBV Core and S proteins, and high vaccination rate (72%). Vaccinated isolated anti-HBs OBIs (n = 31) differed from unvaccinated (n = 11) by significantly younger age (22 vs 38 years), higher anti-HBs level at index (48% vs 9% with anti-HBs100 IU/L) and higher frequency of anti-HBs immune response (44% vs 20%). Of 15 vaccinated and 5 unvaccinated OBIs follow-up, 65% (8 vaccinated and 5 unvaccinated) became HBV DNA negative suggesting aborted recent infection, while 35% (7 vaccinated) had low persistent viraemia 2 to 65 months post index. In conclusion, isolated anti-HBs OBI in Chinese blood donors appears associated with young, vaccinated, adults exposed to HBV who predominantly develop low level aborted infection revealed by transient HBV DNA and immune anti-HBs response. However, a subset of individuals still experienced low but persistent viral replication whose clinical outcome remains uncertain.

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; Hepatitis B virus (HBV) morphogenesis is characterized by a large over-production of subviral particles and recently described new forms in parallel of complete viral particles (VP). This study was designed to depict circulating viral forms in HBV infected patient plasmas, using velocity gradients and most sensitive viral markers. Plasmas from chronic hepatitis B (CHB) patients, HBeAg positive or negative, genotype D or E, were fractionated on velocity and equilibrium gradients with or without detergent treatment. Antigenic and molecular markers were measured in plasma and in each collected fraction. Fast Nycodenz velocity gradients revealed good reproducibility and provided additional information to standard equilibrium sucrose gradients. HBV-RNAs circulated as enveloped particles in all plasmas, except one, and at lesser concentrations than VP. Calculations based on standardized measurements and relative virion and subviral particle molecular stoichiometry allowed to refine the experimental approach. For the HBeAg-positive plasma, VP were accompanied by an overproduction of enveloped capsids, either containing HBs, likely corresponding to empty virions, or for the main part, devoid of this viral envelope protein. Similarly, in the HBeAg-negative sample, HBs enveloped capsids, likely corresponding to empty virions, were detected and the presence of enveloped capsids devoid of HBs protein was suspected but not clearly evidenced due to the presence of contaminating high-density subviral particles. While HBeAg largely influences HBcrAg measurement and accounts for two-thirds of HBcrAg reactivity in HBeAg-positive patients, it remains a 10 times more sensitive marker than HBsAg to characterize VP containing fractions. Using Nycodenz velocity gradients and standardized biomarkers, our study proposes a detailed characterization of circulating viral forms in chronically HBV infected patients. We provide evidence for an excess of capsids in fractions enriched in Dane particles, likely due to the presence of empty virions but also by capsids enveloped by an HBs free lipid layer. Identification of this new circulating viral particle sets the basis for studies around the potential role of these entities in hepatitis B pathogeny and their physiological regulation.

The risk of a blood donation contaminated with hepatitis E virus (HEV) entering the blood supply before introducing universal HEV-RNA screening in France was estimated to assess the benefit of such a measure.The results of selective HEV nucleic acid testing (HEV-NAT) performed in mini pool of six plasma donations between 2018 and 2020 were extrapolated to the whole blood donor (BD) population after adjustment on three variables: regional establishment, sex and age group.Among the 246,285 plasma donations collected from 172,635 BDs tested for HEV-RNA, 248 (10.1/10,000) were positive. The extrapolation to all BDs led to an estimated rate of 5.9/10,000 donations (95% confidence interval [CI]: 4.5-7.4) which would be positive to HEV-RNA and a prevalence of 9.9/10,000 BDs (95% CI: 7.5-12.3). This prevalence was 4.4 times higher in males than females (16.8/10,000 vs. 3.8/10,000, p 10The risk of an HEV-RNA-positive donation entering the blood supply was estimated at 1 in 1682 donations. This risk does not translate directly to the risk of HEV transfusion transmission, which mainly depends on the total number of viral particles in the transfused blood component and the sensitivity of NAT.

International audience; In Sub-Saharan Africa, high clinical demand for transfusion faces endemic bloodborne infections and limited resources. Blood screening for transfusion-transmitted bloodborne pathogens is the cornerstone of blood safety. Although there have been substantial improvements over the years, challenges in transfusion-transmitted infection screening that have been identified repeatedly long ago still need to be addressed. Affordability and sustainability of state-of-the-art quality assessed serological and molecular assays, and associated confirmation strategies remain of real concern. In addition, limited resources and infrastructures hamper the development of adequate facilities, quality management, and staff qualification, and exacerbate shortage of reagents and equipment maintenance. It is also important to maintain effort in constituting pools of repeat voluntary non-remunerated donors. Alternative strategies for blood screening that take into account local circumstances might be desirable but they should rely on appropriate field evaluation and careful economic assessment rather than dogma established from high-resource settings.

Hepatitis B virus (HBV) morphogenesis is characterized by a large over-production of subviral particles and recently described new forms in parallel of complete viral particles (VP). This study was designed to depict circulating viral forms in HBV infected patient plasmas, using velocity gradients and most sensitive viral markers.Plasmas from chronic hepatitis B (CHB) patients, HBeAg positive or negative, genotype D or E, were fractionated on velocity and equilibrium gradients with or without detergent treatment. Antigenic and molecular markers were measured in plasma and in each collected fraction.Fast Nycodenz velocity gradients revealed good reproducibility and provided additional information to standard equilibrium sucrose gradients. HBV-RNAs circulated as enveloped particles in all plasmas, except one, and at lesser concentrations than VP. Calculations based on standardized measurements and relative virion and subviral particle molecular stoichiometry allowed to refine the experimental approach. For the HBeAg-positive plasma, VP were accompanied by an overproduction of enveloped capsids, either containing HBs, likely corresponding to empty virions, or for the main part, devoid of this viral envelope protein. Similarly, in the HBeAg-negative sample, HBs enveloped capsids, likely corresponding to empty virions, were detected and the presence of enveloped capsids devoid of HBs protein was suspected but not clearly evidenced due to the presence of contaminating high-density subviral particles. While HBeAg largely influences HBcrAg measurement and accounts for two-thirds of HBcrAg reactivity in HBeAg-positive patients, it remains a 10 times more sensitive marker than HBsAg to characterize VP containing fractions.Using Nycodenz velocity gradients and standardized biomarkers, our study proposes a detailed characterization of circulating viral forms in chronically HBV infected patients. We provide evidence for an excess of capsids in DNA enriched fractions, likely due to the presence of empty virions but also by capsids enveloped by an HBs free lipid layer. Identification of this new circulating viral particle sets the basis for studies around the potential role of these entities in hepatitis B pathogeny and their physiological regulation.

The diagnostic accuracy of the Elecsys® HCV Duo antigen-antibody combination immunoassay (Roche Diagnostics GmbH) was evaluated for the detection of hepatitis C virus (HCV) infection, versus commercially available comparators.This multicenter study (August 2020-March 2021) assessed the specificity of the Elecsys HCV Duo immunoassay and comparator assays in blood donor and routine clinical laboratory samples; sensitivity was determined in confirmed HCV-positive samples and seroconversion panels. The Elecsys HCV Duo immunoassay was compared with the Monolisa HCV Ag-Ab ULTRA V2, Murex HCV Ag/Ab Combination and ARCHITECT HCV Ag assays, as well as nucleic acid testing (NAT). The antibody (anti-HCV) module of the Elecsys HCV Duo immunoassay was compared with the Elecsys Anti-HCV II, Alinity s Anti-HCV, ARCHITECT Anti-HCV and RIBA HCV 3.0 SIA assays.The specificity of the Elecsys HCV Duo immunoassay was 99.94% (95% confidence interval [CI], 99.89-99.97) and 99.92% (95% CI, 99.71-99.99) in blood donor (n = 20,634) and routine clinical laboratory samples (n = 2531), respectively. The specificity of the Elecsys HCV Duo immunoassay was similar or better than comparator assays. The sensitivity of the Elecsys HCV Duo immunoassay in confirmed HCV-positive samples (n = 257) was 99.6%. In seroconversion panels, the Elecsys HCV Duo immunoassay detected infections earlier (2.2-21.9 days) than all but one of the comparator assays and detected HCV 1.8 days later than NAT.The Elecsys HCV Duo immunoassay shows high diagnostic accuracy, reduces the diagnostic window, and could be used when NAT is not possible.

A study reported in 2019 showed that hepatitis C virus (HCV) could help disseminate hepatitis D virus (HDV). To test this finding, 2123 plasma samples positive for anti-HCV antibody were screened for anti-HDV antibodies, and HDV-RNA was searched for in samples positive for anti-HDV antibody. Of 41 samples (1.9%) that tested positive for anti-HDV antibody, 27 (65.9%) were positive and 14 (34.1%) negative for antibody to hepatitis B core antigen (anti-HBc). Anti-HDV antibodies were significantly more present in samples positive for anti-HBc (6.21% vs 0.8% in negative samples; P < .001) and in samples negative for HCV RNA (2.9% vs 1.5% for positive samples; P = .03). Serological ratios were significantly higher in samples positive for anti-HBc (P < .01). No anti-HDV–positive sample was HDV RNA positive. In conclusion, this study found no evidence suggesting a role for HCV in HDV dissemination in humans.

Background and objectives In France, blood donation deferral for men who have sex with men (MSM) was reduced from permanent to 12 months in July 2016. Assessing noncompliance (rate and reasons) with this criterion is important to maintain a high level of viral safety in blood products. Materials and methods An anonymous online survey (Complidon) of a sample of blood donors was conducted in 2017. Data were post-stratified to be representative of all those who donated blood between July 2016 and December 2017. A multivariable analysis was performed to assess factors associated with noncompliance. Results Among male donors, 0·73% [95% CI: 0·63-0·83] reported having sex with men in the 12 months preceding their donation. Factors associated with noncompliance were as follows: young age, a low educational level, concerns about privacy, and better knowledge of donor selection criteria and the window period than compliant men. More than half of noncompliant MSM donors (57·6% [95% CI: 50·6-64·3]) felt that sexual orientation should not be a criterion for donation, 47·2% [95% CI: 40·4-54·0] did not disclose their male-to-male sexual relations in order to avoid being excluded from donating, 40·5% [95% CI: 34·0-47·4] reported using condoms and 21·8% [95% CI: 16·7-27·9] had the same male partner for at least 12 months. Conclusion Complidon showed that compliance with blood donation criteria in MSM was high, but not optimal, especially among younger men. HIV residual risk did not increase after the implementation of 12-month deferral. Data from Complidon helped French policymakers to assess the additional HIV risk posed by increased access to blood donation for MSM.

Background Several successive arbovirus outbreaks have affected French Polynesia (FP) in the recent past years due to different dengue serotypes (DENV) present for several decades, Zika (ZIKV) (2013–2014) and chikungunya (CHIKV) (2014–2015) viruses with a potential impact on blood safety and blood supply due to the geographical isolation of these islands. This study reports an assessment of the impact of these outbreaks on blood products supply and infectious safety in FP and discuss the effectiveness of implemented preventive measures. Methods To ensure the infectious safety of blood products during outbreaks, several measures have successively been introduced as the selection of donors suspected of infection, the nucleic acid testing (NAT) and the pathogen reduction of platelets and plasmas. Results The donor deferral rate increased by 6% between 2012 and 2014 without changes in the number of collected donations. NAT excluded five blood donations reactive for DENV RNA, 42 for ZIKV and 34 for CHIKV. As Zika screening could not been implemented before the third month of the outbreak, 36 blood products from ZIKV-infected donors were transfused to 26 recipients. However, no transfusion-transmitted arbovirus has been reported. Conclusion The last past arboviruses outbreaks did not have a significant impact on blood supply in FP. The measures introduced to prevent arbovirus transmission by transfusion were able to maintain infectious safety for all blood products without impairing self-sufficiency.

A serological survey of 2,430 archived serum samples collected between 1997 and 2012 was conducted to retrospectively determine the prevalence of Marburg virus in five African countries. Serum samples were screened for neutralizing antibodies in a pseudotype micro-neutralization assay and confirmed by enzyme-linked immunosorbent assay (ELISA). Surprisingly, a seroprevalence for Marburg virus of 7.5 and 6.3% was found in Cameroon and Ghana, respectively, suggesting the circulation of filoviruses or related viruses outside of known endemic areas that remain undetected by current surveillance efforts. However, due to the lack of validated assays and appropriate positive controls, these results must be considered preliminary.

BACKGROUND: There is growing evidence to support the hypothesis that SARS-CoV-2 is probably not transmissible by blood transfusion. In this study, we use the data gathered over one year by the French haemovigilance network on post-donation information related to SARS-CoV-2, and virological investigations on corresponding plasma to explore viral transmission by transfusion. MATERIALS AND METHODS: Whenever a donor reported COVID-19 symptoms and/or a positive SARS-CoV-2 nasopharyngeal (NP) PCR test, information regarding diagnosis and symptoms was collected using a specific questionnaire, and repository plasmas were screened using the SARS-COV-2 R-GENE(®) assay (Biomérieux). RNA sequencing (Sanger and deep sequencing) and virus isolation on Vero E6 cells were applied in plasma from donors testing positive. RESULTS: We investigated 1,092 SARS-CoV-2-related post-donation information (PDI) reports. PDI donors were younger than the global donor population and donated more often in the Paris region. Sixty-eight percent reported a positive NP real-time (RT)-PCR or antigenic testing and 22% of these also had symptoms at the time of testing. Thirty-seven (3.4%) donations tested positive for SARS-CoV-2 RNA, 11 (30%) were confirmed by another molecular assay, and 7 (19%) by sequencing, confirming low viral level. Most RNAemic blood donors donated in southern regions and in Paris. There was no difference in demographic data or duration parameter between RNAemic and non-RNAemic donors. Duration parameter was determined as the time elapsed between donation and: i) the onset of symptoms; ii) a positive NP RT-PCR; and iii) PDI. Cell culture experiments did not show any infectivity related to RNAemic plasmas. DISCUSSION: SARS-CoV-2 RNA can be detected in a small fraction of blood donors with PDI, reporting very low levels of RNA. The corresponding plasma is probably not infectious. These findings highlight the value of haemovigilance and PDI to guide blood safety strategies.

The SARS-CoV-2 Omicron variant displays increased infectiveness as well as mutations resulting in reduced neutralizing activity of antibodies acquired after vaccination or infection involving earlier strains. To assess the ability of vaccinated COVID-19 convalescent plasma (CCP-V) collected before November 2021 to seroneutralize Omicron, we compared neutralizing antibody (nAb) titres of 63 samples against Omicron and earlier B.1 (D614G) strains.Relationship between anti-Omicron titres and IgG anti-S1 levels (binding arbitrary unit: BAU/ml) was studied. Although correlated, anti-Omicron titres were significantly lower than anti-B.1 titres (median = 80 [10-1280] vs. 1280 [160-10,240], p 0.0001). Omicron nAb titres and IgG anti-S1 levels were correlated (Spearman's rank correlation coefficient = 0.67). Anti-S1 IgG threshold at 7000 BAU/ml may allow to discard CCP-V without anti-Omicron activity (nAb titre40). Conversely, only those with highest titres (≥160) had systematically anti-S1 IgG levels7000 BAU/ml.A fraction of CCP-V collected before November 2021 retains anti-Omicron seroneutralizing activity that may be selected by quantitative anti-IgG assays, but such assays do not easily allow the identification of 'high-titre' CCP-V. However, collecting plasma from vaccinated donors recently infected with Omicron may be the best option to provide optimal CCP-V for immunocompromised patients infected with this variant.

Background Blood donor selection, consisting of a pre-donation questionnaire and interview, excludes potential donors who may be at risk of transfusion-transmissible infections. Assessing the reasons for noncompliance with blood donor selection criteria is important to maintain a high level of viral safety of blood products. Study design and methods An anonymous French online survey of a sample of blood donors (Complidon) was conducted from September to December 2017. Data were poststratified to be representative of all donors who donated blood between July 2016 and December 2017. Results Of 420,190 solicited donors, 108,386 completed the survey (26%). Overall, noncompliance was estimated at 5.6%. The least respected criteria regarded sex with more than one partner during the previous 4 months for donors (1.9%) and for donors' partners (1%), travel-related criteria (1.2%) and sex between men during the previous 12 months (0.73% of men). Reasons for noncompliance differed according to criteria. Donors who were non-compliant to sexuality-based criteria mainly said they did not want to be excluded or that the questions were too personal. Conversely, donors who were exclusively non-compliant to criteria other than sexuality-based criteria more often mentioned their non-compliance during the pre-donation interview but were nevertheless authorized to donate blood. Conclusion Despite noncompliance to blood donor criteria being relatively low in France, it still represents a threat to blood safety. Accordingly, improved communication is important to ensure that donors fully understand each selection criterion and to emphasize to health professionals the importance of listening carefully without judging during pre-donation interviews.

International audience; Background: False positivity in blood screening may cause unnecessary deferral of healthy donors and exacerbate blood shortages. An international multicenter study was conducted to estimate the frequency of HCV and HIV false seropositivity in seven African countries (Burundi, Cameroon, Democratic Republic of Congo, Madagascar, Mali, Mauritania, and Niger).Study design and methods: Blood donations were tested for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) with rapid detection tests (RDTs), third-generation enzyme immunoassays (EIAs), or fourth-generation EIAs. HCV (456/16,613 [2.74%]) and HIV (249/16,675 [1.49%]) reactive samples were then confirmed with antigen/antibody assays, immunoblots, and nucleic acid testing. Partial viral sequences were analyzed when possible.Results: The HCV reactivity rate with RDTs was significantly lower than with EIAs (0.55% vs. 3.52%; p < 0.0001). The HIV reactivity rate with RDTs was lower than with third-generation EIAs (1.02% vs. 2.38%; p < 0.0001) but similar to a fourth-generation assay (1.09%). Only 16.0% (57/357) and 21.5% (38/177) of HCV and HIV initial reactive samples, respectively, were repeatedly reactive. HCV and HIV infections were confirmed in 13.2% and 13.7%, respectively, of repeated reactive donations. The predominant HCV genotype 2 and 4 strains in West and Central Africa showed high genetic variability. HIV-1 subtype CRF02_AG was most prevalent.Conclusion: High rates (>80%) of unconfirmed anti-HCV and anti-HIV reactivity observed in several sub-Saharan countries highlights the need for better testing and confirmatory strategies for donors screening in Africa. Without confirmatory testing, HCV and HIV prevalence in African blood donors has probably been overestimated.

Anti-hepatitis A virus (HAV) antibody titers at 20 IU/L are assumed to correlate with protection against HAV challenge.We examined the accuracy and precision of currently in use immunoassays for total or anti-HAV IgG determination, by repeated testing of dilutions of the international anti-HAV standard, within a 10-50 IU/mL concentration range.Eight immunoassays were evaluated. All could confidently identify people who need to be vaccinated, or who might benefit from a booster vaccine: no positive interpretation for the 10 and 15 IU/mL concentrations. However, qualitative interpretation may differ from test to test in the 15-30 IU/mL range. This variation has to be taken into account when comparing seroprevalence data.

We conducted a serologic survey of 2,430 serum samples collected during 1997-2012 for various studies to determine the prevalence of the hemorrhagic fever virus Ebola virus (EBOV) in equatorial Africa. We screened serum samples for neutralizing antibodies by using a pseudotype microneutralization assay and a newly developed luciferase immunoprecipitation system assay. Specimens seroreactive for EBOV were confirmed by using an ELISA. Our results suggest a serologic prevalence of 2%-3.5% in the Republic of the Congo and the Democratic Republic of the Congo, which have reported outbreaks of infection with EBOV. In addition we detected a seroprevalence of 1.3% in southern Cameroon, which indicated a low risk for exposure in this region.

Resume Depuis l’affaire francaise tres mediatisee du « sang contamine » un ensemble de reglementations specifiques et de procedures ont ete etablies pour ameliorer la securite transfusionnelle. L’amelioration des techniques de preparation des produits sanguins labiles y a contribue egalement. La mise en place d’une organisation de l’hemovigilance (creee en 1993) a permis d’identifier et de definir l’incidence des differents effets indesirables de la transfusion sanguine. Les risques encourus lors d’une transfusion sanguine, meme s’ils ne sont pas tres frequents, sont suffisamment graves pour justifier une evaluation prealable du rapport benefice-risque par les medecins. Les complications de la transfusion sont directement en relation avec le terrain, le capital genetique du patient transfuse, la qualite des produits sanguins labiles administres mais egalement en lien avec le defaut de pratique. Elles ont change en France au fil des annees. Actuellement, le risque viral a fortement recule et les reactions febriles non hemolytiques et les allergies representent aujourd’hui les principales complications de la transfusion. Le risque immunologique apparait maintenant nettement superieur au risque infectieux. La surcharge vasculaire represente encore la premiere cause de mortalite post-transfusionnelle en France. Ce travail a ete redige pour fournir aux acteurs de la transfusion une synthese sur les complications de la transfusion sanguine. Elles ne sont pas comparables suivant les pays en raison de l’heterogeneite des preparations des produits sanguins labiles, des differentes politiques de prevention dans la selection des donneurs et de la diversite de fonctionnement des systemes d’hemovigilance (systematique ou selectif). Dans cette revue generale, nous etudierons les complications de la transfusion selon le mecanisme physiopathologique. Nous insisterons sur les complications graves menacant le pronostic vital. La premiere partie etant consacree aux complications immunologiques, la deuxieme aux complications infectieuses, la troisieme aux accidents de surcharge. La derniere partie s’interessera tout particulierement a la transfusion massive.

BACKGROUND In France, the risk of HIV transmission by transfusion was reduced by implementing pooled nucleic acid testing (NAT) in 2001 and individual NAT in 2010. We report here the first case in France of transfusion of human immunodeficiency virus (HIV)-infected blood donated during HIV pre-ramp-up phase that tested individual NAT negative. METHODS Blood donations are screened for HIV antibodies and HIV RNA (ProcleixUltrio, Grifols; limit of detection at 95%, 23 copies/mL). When a repeat donor tests positive for HIV, a repository sample from the previous donation is tested with the Cobas Taqman HIV-1 test (CTM, Roche; limit of detection at 95%, 17 copies/mL). RESULTS In August 2017, a 57-year-old male repeat donor was screened positive for HIV antibodies and RNA (plasma viral load, 11,599 copies/mL). The previous donation had tested negative with Ultrio in March 2017 but was positive with an unquantifiable plasma viral load when tested with CTM. Sequencing showed no mismatch between Ultrio primers/probes and the target sequence. HIV transmission was excluded by lookback studies in the recipient of platelets, which had been pathogen reduced, but not in the recipient of RBCs due to premature death. CONCLUSION This case demonstrates that the risk of contaminated donations due to the early HIV infection phase going undetected by highly sensitive NAT is real but exceptional. The absence of transmission to the platelets recipient could be due to the very low viral inoculum and/or to the efficacy of the viral inactivation. This case also highlights the additional value of a systematic donation archiving and the importance of donor education and predonation selection.

Background: Capacity building of African based blood services researchers has been identified as key in developing a sustainable programme of generation local evidence to support sound decision making. There are a number of research training programmes that have been instituted targeted at blood services in Africa. The article shares programme experiences of building research capacities for blood services in Africa.\ud \ud Methodology: The Francophone Africa Transfusion Medicine Research Training network, the NIH REDS-III and NIH Fogarty South Africa programmes and T-REC (Building research capacities in Africa) have been the key research capacity programmes targeting blood services in Africa over the last decade. Data were drawn from research outputs, publications and end of programme reports. The focus was to understand their experiences on the implementation of the capacity building programmes highlighting the success, challenges and the main research outputs from their initiatives.\ud \ud Results: The Francophone research network achievements included more than 135 trainees and in excess of 30 publications. The NIH REDS study the achievements included more than 12 research publications with South Africa junior investigators as lead authors. The NIH Fogarty program currently includes 56 short course trainees, 5 Masters and 6 PhD candidates. The four year (2011-2015, funding period) T-REC research capacity has as of 2020 managed to produce 4 PhDs, 42 in-service Diploma in Project Design and Management (DPDM), and supported bursaries for 60 Masters/undergraduate research. The main common challenges in the running of the research programmes include shortages of in-country mentoring and identified needs in high quality research grants writing.\ud \ud Discussion and conclusion: It has been noted that the key achievements for the blood services research capacity building include a mix of short courses, medium-term (epidemiology & biostats) and MS/PhD degree training. Also, having a train the trainers to develop in-country mentors has been instrumental. Overall, the key recommendations for blood services research capacity building include the need for research collaborations with high-income countries which can jump-start research. For a sustainable research programme, eventually there is need for in-country grant-writing capacity building.

International audience; To date, blood banks apply routine diagnosis to a specific spectrum of transfusion-transmitted viruses. Even though this measure is considered highly efficient to control their transmission, the threat imposed by emerging viruses is increasing globally, which can impact transfusion safety, especially in the light of the accelerated viral discovery by novel sequencing technologies. One of the most important groups of patients, who may indicate the presence of emerging viruses in the field of blood transfusion, is the group of individuals who receive multiple transfusions due to hereditary hemoglobinopathies. It is possible that they harbor unknown or unsuspected parenterally-transmitted viruses. In order to elucidate this, nucleic acids from 30 patients with beta-thalassemia were analyzed by Illumina next-generation sequencing and bioinformatics analysis. Three major viral families: Anelloviridae, Flaviviridae and Hepadnaviridae were identified. Among them, anelloviruses were the most representative, being detected with high number of reads in all tested samples. Human Pegivirus 1 (HPgV-1, or GBV-C), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) were also identified. HBV and HCV detection was expected due to the high seroprevalence in patients with beta thalassemia. Our results do not confirm the presence of emerging or unsuspected viruses threatening the transfusion safety at present, but can be used to actively search for viruses that threaten blood transfusion safety. We believe that the application of viral metagenomics in multiple-transfused patients is highly useful to monitor possible viral transfusion threats and for the annotation of their virome composition.

International audience; Background: Multiplex viral nucleic acid testing (NAT) and a discriminatory testing algorithm have been used to detect viral infections in blood donors. Non-discriminated reactive (NDR) results may arise from low hepatitis B virus (HBV) DNA levels and are challenging for donor management by blood services. The aim of this study was to evaluate the performance and feasibility of alternative viral particle concentration methods to confirm and to characterise HBV infection status in NDR donors from Dalian, China, in order to improve routine donor management according to the potential residual risk estimate.Materials and methods: Individual donations were tested with ULTRIO Plus, and discriminated when reactive. Virions were concentrated from 12 and 6 mL plasma samples by ultracentrifugation (UC) and polyethylene glycol (PEG) precipitation, respectively. HBV DNA was detected with four nested polymerase chain reactions (95% limit of detection: 5-25 IU/mL). Amplified products were sequenced for definitive confirmation. Anti-HBc and anti-HBs were tested.Results: Of 77,556 donors, 79 (0.1%) were NAT NDR. After viral particle concentration by UC and PEG precipitation, HBV DNA was detected in 46 (58.2%) and 34 (43.0%) NDR donors, respectively, including 61.7% of samples that were repeatedly non-reactive with multiple NAT testing. Anti-HBc and anti-HBs (median titre: 37 mIU/mL) were detected in 87.3% and 46.8% of NDR donors, respectively. Sequencing confirmed HBV DNA in 65.8% of NDR donors, of whom 96.2% were occult HBV carriers with rare mutations in S and core proteins.Discussion: A HBV DNA confirmatory procedure with limited technical constraints was implemented successfully. The majority of NDR donors had occult HBV infections with extremely low viral DNA levels, which may constitute a potential residual threat for blood safety. Only a minority of anti-HBc+ NDR donors had anti-HBs levels high enough to consider their reinstatement as donors. The data support the permanent deferral of NDR donors to ensure maximum blood safety in areas of high HBV endemicity.

International audience; The diagnosis of chronic mountain sickness (CMS) is based on a score including 7 clinical features (breathlessness, sleep disturbance, cyanosis, venous dilatation, paresthesia, headache, and tinnitus) in the setting of extreme erythrocytosis. Examining individuals in La Rinconada, Peru, the highest city in the world, the authors demonstrated that CMS at extreme altitude is not linked to elevation of hemoglobin, since CMS+ and CMS− individuals had similar levels of erythrocytosis.

International audience; The high genetic variability of hepatitis B virus (HBV) can impair DNA quantification. Here, we investigate a major underquantification of HBV by the cobas TaqMan HBV assay (CTM; Roche). In France, between 2005 and 2017, HBV DNA was detected in 3,102 blood donations by use of the CTM (95% limit of detection [LOD], 4.8 IU/ml). HBV strains were sequenced in the S region (LOD, ∼30 IU/ml). Concordant (n = 120) and discordant (n = 45) samples were identified according to the agreement between the plasma viral load (pVL) determined by the CTM and sequencing; all samples were also quantified using the RealTime HBV assay (RTH; Abbott). The viral signature, cloning, and mutagenesis were used to characterize the polymorphism responsible for CTM misquantification. A CTM-RTH discordance (>1 log IU/ml) was found in 14/45 samples that had low pVLs and were successfully genotyped (pVL genoS). PreC/C clones of concordant (C1, C2) and discordant (D1, D2) strains were used to challenge the CTM. Strains D1 and D2 were highly underquantified (42- and 368-fold). In clones, mutating the region corresponding to the CTM reverse primer from a discordant sequence to a concordant sequence restored the levels of quantification to 24% (D1→C1) and 59% (D2→C1) of theoretical levels, while mutating the sequence of a concordant strain to that of a discordant strain led to 78-fold (C1→D1) and 146-fold (C1→D2) decreases in quantification. Moreover, mutating positions 1961 and 1962 was enough to induce a 5-fold underquantification. We conclude that the CTM underestimates pVLs for HBV strains with mutations in the reverse primer target. Specifically, the polymorphism at nucleotides 1961 and 1962 is naturally present in 4.79 and 4.22% of genotype A and D strains, which are highly frequent in Europe, leading to a 5-fold decrease in quantification. Quantification using the new-generation Roche C4800 assay is not affected by this polymorphism.

In the WHO Universal test and treat strategy, false-positive HIV blood donors and patients may be unnecessarily put under antiretroviral treatment and false-negative subjects may be lost to follow-up. This study assessed the false positivity rate of the Cameroonian national HIV screening testing algorithm and the benefit of a confirmation test in the enrolment of patients and donors in the HIV care programme.We included initial HIV reactive blood donors and patients in a cross-sectional study conducted in two Cameroonian hospitals. Samples were retested according to the Cameroon national algorithm for HIV diagnosis. A positive or discordant sample was retested with the Geenius Bio-Rad HIV 12 (Bio-Rad, Marnes-la-Coquette, France) for confirmation. The Geenius HIV-1-positive results with 'poor' profiles were retested for RNA as well as the Geenius indeterminate results.Of the 356 participants, 190/225 (84·4%) patients and 76/131 (58%) blood donors were declared positive with the national algorithm; 257 participants (96·6%) were confirmed HIV-1-positive. The study revealed that about 34/1000 blood donors and patients are false-positive and unnecessarily put on treatment; 89/1000 blood donors and patients declared discordant could have been included immediately in the HIV care programme if confirmatory testing was performed. The second test of the algorithm had a false-negative rate of 3%. Eleven samples (3·1%) were Geenius poor positive and NAT negative.The universal test and treat strategy may identify and refer more individuals to HIV care if a third rapid confirmatory test is performed for discordant cases.

International audience; Background: Hepatitis B surface antigen (HBsAg) remains the main viral marker for screening and monitoring hepatitis B virus (HBV) infection. The quantification limit of most current HBsAg assays is around 0.05 IU/mL. The Lumipulse-G-HBsAg-Quant assay (Fujirebio) claims to obtain a tenfold improvement in sensitivity. This study aimed to assess the performance of this assay in detecting low HBsAg levels in clinical samples.Methods: Three panels of stored frozen samples were selected on the basis of HBV-DNA and HBsAg values obtained previously with routine techniques. Panels 1 (n=13) and 2 (n=52) consisted of DNA-positive/HBsAg-negative samples from individuals in the window period and with occult HBV infection respectively. Panel 3 comprised 23 samples with low or discrepant HBsAg screening results. All these samples were tested retrospectively with the DiaSorin and Fujirebio HBsAg assays.Results: Sixteen out of 65 samples (25 %), initially screened HBsAg negative, were reactive only with the Fujirebio assay (median value= 0.015 IU/mL; IQR= 0.012): three (23 %) samples from panel 1 and 13 (25 %) from panel 2. Thirteen of these 16 (81 %) had HBsAg values below 0.03 IU/mL with the DiaSorin assay. In panel 3, 22 (96 %) samples were quantified successfully with the Fujirebio assay (median: 0.32 IU/mL; IQR: 1.20) and 19 (83 %) with the DiaSorin assay (median: 0.31 IU/mL; IQR: 0.65). Concentrations obtained with the two assays showed good correlations (r=0.893, Spearman).Conclusions: HBsAg assays with enhanced analytical sensitivity could improve HBV serological profile interpretation with possible consequences on clinical management of infected patients, and on blood transfusion safety.

Background: A massive scale-up of testing and treatment is indicated to globally eliminate hepatitis B virus (HBV) infection. However, access to a polymerase chain reaction (PCR), a key test to quantify HBV DNA levels and determine treatment eligibility, is limited in resource-poor countries. We developed and evaluated loop-mediated isothermal amplification (LAMP) assay to diagnose clinically important HBV DNA thresholds defined by WHO (≥20,000 and ≥200,000 IU/mL) in both resource-rich (Europe) and resource-limited (Africa) contexts. Methods: Pan-genotypic primer sets were designed on conserved HBV gene regions. Accuracy of LAMP to identify highly viraemic patients was evaluated using 400 and 550 HBV-infected samples from France and Senegal, respectively. Findings: Our primers successfully detected eight major HBV genotypes/sub-genotypes (A1/2/3/B/C/D/E/F) with a detection limit ranging between 40-400 IU/mL. In France, the area under the receiver operating characteristic curve (AUROC), sensitivity and specificity of bead-based extraction and real-time turbidimetric LAMP were 0.95 (95% CI: 0.93-0.97), 91.1% and 86.0%, respectively, to diagnose HBV DNA ≥20,000 IU/mL; and 0.98 (0.97-0.99), 98.0% and 94.6% for ≥200,000 IU/mL. The performance did not vary by viral genotypes. In Senegal, using a field-adapted method (reagent-free boil-and-spin extraction and inexpensive end-point fluorescence detection), the AUROC, sensitivity and specificity were 0.95 (0.93-0.97), 98.7% and 91.5%, respectively, to diagnose HBV DNA ≥200,000 IU/mL. Interpretation: We developed a simple, rapid (60 minutes), and inexpensive (US$ 8/assay) alternative to PCR to diagnose high viremia ≥200,000 IU/mL. HBV-LAMP may contribute to eliminating HBV mother-to-child transmission by identifying high-risk pregnant women eligible for antiviral prophylaxis in resource-limited countries. Funding Statement: ValoExpress [ANR11-CARN017-01] and Grand Challenges Africa [GCA/ISG/Round1/045]. Declaration of Interests: MS is employee of Eiken Chemical Co.,Ltd. All the other authors declare no conflict of interest. Ethics Approval Statement: The study was approved by the Clinical Research Committee at the Institut Pasteur (n° 2016-057) and the National Ethics Committee in Senegal (SEN17/59) .All donors are informed of a potential use of their samples for research and have given their written consent.

BACKGROUND AND OBJECTIVES The Francophone Africa Transfusion Research Network conducted the first large and comprehensive surveys on the status of blood safety in francophone African countries in 2009 and 2012. Since then, there has been substantial investment in blood safety but little is known about progress made in the region. MATERIALS AND METHODS This multicentre cross-sectional study describes characteristics of blood services, donors and blood products and compares results with previous data. A web-based questionnaire collected data of 2016 from 38 blood facilities in 11 French-speaking countries. Data were analysed according to type of blood services and compared to similar studies conducted in 2009 and 2012. RESULTS The study included data on 572 933 donations from 366 844 donors. Compared to 2012, there was an increase in the median proportion of voluntary nonremunerated blood donation (+22%) (P = 0·004), and a reduction from 2·1 to 0·9 (P = 0·01), from 10·3 to 6·7 (P = 0·00), from 3·2 to 1·3 (P = 0·006) and from 1 to 0·4 (P = 0·03) in median seroprevalences of HIV, HBV, HCV and syphilis, respectively. The median proportion of blood orders fulfilled decreased (-18·2%) (P = 0·001). The number of technical staff per 1000 donations ranged from 1 to 54 with hospital-based blood transfusion services having 12-fold more staff than National and Regional services. CONCLUSION Several indicators have improved in Francophone Africa Blood services during the last 5 years and national and regional services likely have better indicators than hospital-based services. These findings may support the need for ongoing blood safety initiatives.

La question de la transmission par le sang du SARS-CoV-2 s'est posee lorsqu'une etude chinoise rapportait en mai 2020 la presence d'ARN viral dans le plasma de DS asymptomatiques. L'evaluation du risque transfusionnel lors d'une emergence virale s'opere sur 5 criteres : – la capacite du virus a diffuser dans la population ;– une viremie asymptomatique ;– la transmissibilite par le sang ;– la persistance de l'agent dans le produit sanguin a l'issue de sa preparation et sa conservation ;– les consequences pour le patient-transfuse. Par sa transmission aerienne, le SARS-CoV-2 a eu une diffusion planetaire responsable d'une pandemie sans precedent. La presence d'ARN plasmatique a ete relevee a de faibles concentrations chez des patients avec une frequence moyenne de 10 % mais d'autant plus importante que l'infection etait severe (0–72 %). Des etudes chez les DS asymptomatiques ont aussi montre son existence : 0–0,3 % lors de depistages systematiques et environ 3 % chez les DS ayant fait une IPD. L'infectiosite du plasma in vitro ou lors d'enquetes ascendantes ou descendantes n'a jamais ete observee. L'inactivation des pathogenes est efficace vis-a-vis des coronavirus. Aucun element ne permet d'attester que la detection de l'ARN viral au niveau plasmatique se traduit par le pouvoir infectieux des produits sanguins. Il peut s'agir de formes virales degradees ou d'une voie de transmission non propice a l'infection. Malgre un risque hypothetique, des mesures securitaires conservatoires sont en vigueur avec un ajournement de 14 jours des DS apres resolution des symptomes d'une infection confirmee ou cas-contact. La vaccination concourra indirectement a la reduction d'un risque eventuel. (French) [ABSTRACT FROM AUTHOR] Copyright of Transfusion Clinique et Biologique is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La forme variante de la maladie de Creutzfeldt-Jakob (vMCJ) est une maladie a prion, fatale, entrainant la destruction progressive des neurones. Elle resulte generalement de l’ingestion de viande bovine contaminee mais serait egalement transmissible par le sang. Malgre le declin de l’epidemie dans le monde, des incertitudes demeurent quant a la prevalence dans la population generale de porteurs asymptomatiques potentiellement capables de transmettre la maladie par transfusion sanguine ou par d’autres procedures medicales. Objectifs Evaluer l’existence de porteurs silencieux de l’infection vMCJ et la transmission transfusionnelle dans une population de patients polytransfuses. Methodes Nous avons publie le premier test permettant de detecter l’agent vMCJ dans des echantillons sanguins y compris au stade pre-symptomatique (Bougard et al., Sci Transl Med 2016). Ce test combine une capture des proteines prions sur des nanobilles et une etape d’amplification specifique du vMCJ afin de detecter des quantites infimes de prion dans le plasma. Nous avons analyse un panel de 100 echantillons issus de patients atteints d’anemie constitutionnelle, et multi-transfuses (en moy. 119 CGR recus) inclus dans la bio collection BOTIA (Blood and Organ Transmissible Infectious Agents) constituee de couples d’echantillons de donneurs/receveurs apparies avec un suivi longitudinal. Resultats Aucun des 100 echantillons de plasma analyses par notre test ultrasensible n’a ete detecte positif pour l’agent responsable de la vMCJ. Conclusions Ces resultats sont en faveur de la securite de la chaine transfusionnelle vis-a-vis du risque prion et seront a confirmer par des etudes a plus grande echelle.

BACKGROUND In France, information collected during postdonation interviews showed that a majority of human immunodeficiency virus (HIV)-infected donors were not eligible to donate as per donor selection criteria. In the interest of blood safety, this study aimed to explore the mechanisms of noncompliance with blood donor selection criteria, notably the permanent deferral of men who have sex with men (MSM). STUDY DESIGN AND METHODS Semistructured individual interviews were conducted with 32 blood donors found positive for HIV between mid-2011 and 2014. Topics such as the experience and motivations for donating blood, understanding of selection criteria, sexual risk management, and opinions on donor selection were discussed. Transcripts were analyzed inductively. RESULTS More than 50% of study participants were noncompliant with donor selection criteria. Reasons for nondisclosure of risk factors in the predonation questionnaire or the predonation interview included stigma, test-seeking motivations, symbolic attachment to blood donation, and context of donation. Compliance to donor criteria was seen as secondary by donors who reaped personal benefits from the symbolism of their donation. Donors lacked self-reflexivity in their assessment of risky sexual behavior. The “window period” and the underlying epidemiologic arguments for donor selection criteria were poorly understood. Nearly all participants disapproved of the permanent ban on blood donations from MSM. CONCLUSION This study demonstrated the need for more communication on the epidemiologic basis for donor selection criteria and on the window period to facilitate donor compliance. These findings have already advanced improvements to predonation documents, in a larger context of 2016 donor selection criteria revision.