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To reduce the risk of HIV transmission through transfusion, gay, bisexual and other men who have sex with men (gbMSM) are deferred from donating blood in many countries for varying lengths of time after having sex with another man. In 2021, screening algorithms to identify high-risk sexual behaviours using gender-neutral criteria (i.e., without any question on MSM or time deferral for MSM) were implemented in the United Kingdom based on recommendations in a report from the FAIR (For the Assessment of Individualised Risk) steering group.This study examines the potential donation loss expected with these criteria if implemented in Canada.Responses from blood donors regarding engagement in behaviours such as chemsex and anal sex with a new or multiple partners within 3 months of donation were collected using an on-site paper questionnaire.Applying the FAIR criteria resulted in donation loss of 1.0% (95% CI: 0.8% - 1.1%). Donation loss would be higher amongst younger donors aged 17-25 (2.0%, 95% CI: 1.6% - 2.3%). Overall, 20% of donors reported feeling uncomfortable answering study questions but only 2.0% said it would stop them from donating.Donation loss could be compensated by newly eligible gbMSM and with increased recruitment and encouraging donation from infrequent donors.

In Québec (Canada), the donation deferral for men who have sex with men (MSM) has recently been shortened to 3 months. Whether this change impacted compliance with pre-donation screening is unknown. We assessed compliance with the disclosure of male-to-male sex and other behavioural risk factors for HIV amid this change.Québec residents who donated from 14 July 2020 to 30 November 2020 were invited to participate in an online survey. Donors were informed that the survey was optional and anonymous. Survey questions were those used for routine pre-donation screening. Rates of reported non-compliance were weighted based on several characteristics.Of 21,918 contacted donors, 7113 (32.45%) participated. Among male participants (N = 3347), six (0.27% [95% confidence interval (CI) = 0.09%-0.44%]) were not compliant with a 3-month MSM deferral. Among female participants (N = 3766), two (0.06% [95% CI = 0.00%-0.13%]) were not compliant with a 3-month deferral for sex with a man who had male-to-male sex ≤12 months. Other risk factors exhibited similar or lower rates of reported non-compliance.Reported non-compliance with a 3-month MSM deferral and the disclosure of other HIV behavioural risk factors was low. These results warrant the investigation of behavioural donor risk assessment approaches to further improve the inclusiveness of blood donation.

Background and Objectives: Blood donors are increasingly being recognized as an informative resource for surveillance. We aimed to review severe acute respiratory syndrome coronavirus 2 seroprevalence studies conducted among blood donors to investigate methodological biases and provide guidance for future research. Materials and Methods: We conducted a scoping review of peer-reviewed and preprint publications between January 2020 and January 2021. Two reviewers used standardized forms to extract seroprevalence estimates and data on methodology pertaining to population sampling, periodicity, assay characteristics, and antibody kinetics. National data on cumulative incidence and social distancing policies were extracted from publicly available sources and summarized. Results: Thirty-three studies representing 1,323,307 blood donations from 20 countries worldwide were included (sample sizes ranged from 22 to 953,926 donations). The majority of the studies (79%) reported seroprevalence rates

Background and objectives Early in the pandemic, the transmissibility of coronavirus disease-19 (COVID-19) by transfusion was unknown. We piloted a systematic, post-donation outreach programme to contact blood donors and inquired about symptoms post-donation. Materials and methods Persons who donated on on May 1 and 2, 2020 were contacted 3 days post-donation, by phone to assess COVID-19-related symptoms. Half of the donors were administered a short questionnaire, consisting of only three questions. Others were questioned using a longer, more specific questionnaire. If symptoms were reported, products were quarantined until donors were contacted again by a trained nurse who more thoroughly assessed the likelihood of COVID-19. Blood products were withdrawn if symptoms indicative of COVID-19 were identified. Results Of 654 donors, 609 (93.1%) were successfully contacted. Of 310 donors who answered the short questionnaire and 299 who answered the long questionnaire, 19 (6.1%) and 8 (2.7%) had one or more symptoms, respectively. Based on the nurses' assessment, two donations (0.3%) had to be withdrawn. Conclusion These results suggest that actively seeking post-donation information might be feasible to mitigate emerging, unqualified transfusion risks.

In late 2019 the respiratory illness, Corona Virus Disease-19 caused by the SARS-CoV-2 virus emerged in China and quickly spread to other countries. The primary mode of transmission is person-to-person via respiratory droplets. SARS-CoV-2 has been identified in conjunctiva. Transmission by cornea transplant has not been reported but is theoretically possible. We aimed to estimate the possible risk of transmission in Canada via cornea transplant during the first wave of the pandemic, and the potential risk reduction from testing decedents. We constructed a deterministic model in which the risk of transmission was estimated as the product of three proportions: decedents with SARS-CoV-2 infection, corneas that are NAT positive, and NAT positive corneas presumed to transmit. Risk was estimated according to 3 scenarios: most likely, optimistic and pessimistic. At the peak of the first wave of the pandemic risk was estimated to be 1 in 63,031 cornea transplants in Canada but could be as low as 1 in 175,821 or as high as 1 in 10,129. It would take 16 years at the peak infection of the first wave of the pandemic to observe 1 transmission. Testing would reduce the risk of 1 in 63,031 to 1 in 210,104 assuming 70% test sensitivity. The theoretical risk of SARS-CoV-2 transmission by cornea transplant is extremely low and decedent testing is unlikely to be beneficial.

Background and Objectives: The COVID-19 pandemic has brought to the fore how blood services can partner with public health (PH) authorities to inform decisions. Yet the scope of partnerships between blood services and PH authorities is inadequately documented. We explored how blood services partner with PH authorities outside the scope of COVID-19. Materials and Methods: On 19 January 2022, survey was sent to employees of blood services located throughout the world. Survey questions mainly pertained to partnerships with PH authorities, including how blood specimens are used and collected. Results: Twenty-seven recipients—4 (14.8%) in Africa, 3 (11.1%) in Asia, 9 (33.3%) in Europe, 6 (22.2%) in North America, 2 (7.4%) in Oceania and 3 (11.1%) in South America—completed the survey. Fifteen recipients (55.6%) indicated their blood service was directly or indirectly supervised by PH authorities. Twenty-four recipients (88.9%) indicated currently using or planning to use blood donor data or samples for PH research or pathogen surveillance. A substantial proportion of respondents reported using samples or results from non-routine tests for the surveillance of non-transfusion-transmitted infectious disease pathogens (n = 13 [48.1%]); samples or results of non-routine tests for PH research unrelated to pathogens (n = 10 [37.0%]); donor data for PH research unrelated to pathogens (n = 12 [44.4%]) and donor data for PH research unrelated to transfusion safety (n = 11 [40.7%]). Fourteen (51.9%) had established (or planned to establish) longitudinal cohorts and 19 (70.4%) biobanks. Conclusion: The majority of responding blood services were already involved in or planned to be involved in PH research or pathogen surveillance.

Minimizing the risk of vasovagal reactions (VVRs) can prevent donor harms and improve donor return. We report the results of a program to reduce VVR rates.The program was implemented on June 11, 2017 and consisted in drinking water and eating a salty snack before donating blood, plasma, or platelets. All donations made during the "pre-program period" (October 11, 2015-June 10, 2017) and "post-program period" (June 11, 2017-May 11, 2019) were included. Study outcomes comprised VVRs (any severity) and syncopal VVRs, whether employee- or donor-reported. An interrupted time series (ITS) analysis proxied causality based on the "pre-program trend," the "immediate trend" (i.e., immediately before versus after the program), and the "post-program trend". The relative risk (RR) of VVR (along with confidence intervals [CIs]) was reported, overall and stratified by subgroups based on age, sex, donor type (i.e., first-time versus repeat), and donation type (i.e., whole blood versus apheresis).The monthly VVR rate (any severity) dropped from 4.6% in the pre-program period to 4.3% in the post-program period, and never reached its pre-program level. The ITS analysis revealed a statistically significant and increasing pre-program trend (RR [95% CI] = 1.011 [1.002-1.020]), a statistically significant and decreasing immediate trend (RR [95% CI] = 0.848 [0.743-0.969]), and a non-statistically-significant and stable post-program trend (RR [95% CI] = 0.999 [0.993-1.006]). Similar trends were observed for nearly all high- and low-risk subgroups. No statistically significant trend was observed for syncopal VVRs.These results suggest that the herein-described program durably reduced the incidence of VVRs (any severity) by ~15%.

Several blood services might eventually interview donors with gender-neutral questions on sexual behaviors to improve the inclusivity of blood donation. We tested two ways (i.e., "scenarios") of asking donors about their recent sexual behaviors.The study comprised 126 regular source plasma donors and 102 gay, bisexual, and other men who have sex with men (gbMSM), including 73 cis-gbMSM (i.e., the "cis-gbMSM subgroup," which excluded nonbinary, genderqueer, and trans individuals). In Scenario 1, participants were asked if, in the last 3 months, they "have […] had a new sexual partner or more than one sexual partner." In Scenario 2, they were asked "Have you had a new sexual partner?" and "have you had more than one sexual partner?". Validation questions included more specific questions on the type of partners and sexual activity.Among plasma donors, sensitivity was 100.0% for both scenarios; specificity was 100.0% and 99.1% for Scenarios 1 and 2, respectively. Among gbMSM, sensitivity was 74.5% and 82.9% for Scenarios 1 and 2, respectively; specificity was 100.0% for both scenarios. Among cis-gbMSM, sensitivity was 88.6% and 100.0% for Scenarios 1 and 2, respectively; specificity was 100.0% for both scenarios. The area under the receiver operating characteristic curve of Scenario 2 was significantly higher than that of Scenario 1 among gbMSM and in the cis-gbMSM subgroup (all p .05).Scenario 2 questions performed well among plasma donors and cis-gbMSM, but less so in the broader gbMSM population.

Background and objectives In Canada, men having sex with men (MSM) are deferred for 3 months from last sexual contact to reduce human immunodeficiency virus (HIV) risk to recipients. The aim of this paper was to model the Canadian residual risk of HIV-positive source plasma incorporating pathogen inactivation (PI) under no MSM deferral scenarios for apheresis plasma donations. Materials and methods A combined Bayesian network (BN) and Monte Carlo approach were implemented to estimate the HIV residual risk under 3-month deferral compared with no deferral without quarantine scenarios for MSM donors. Models involve the stochastic generation of donation and its infection status based on its corresponding simulated donor profile. Viral load reduction conferred by PI used by source plasma fractionators was simulated. Model parameters were derived from Hema-Quebec and Canadian Blood Services data, viral loads in a large sample of HIV-positive US blood donors, CSL Behring documentation and from published data. Results In the most likely scenario for the 3-month deferral model, there were 2.71 positive donations per 1,000,000 donations (95% confidence interval [CI] 2.63-2.78). For the no-deferral model, there were 3.01 positive donations per 1,000,000 donations (95% CI 2.94-3.09). For both scenarios, the risk of having an infectious pool was 0 in 300,000 pools (95% CI 0-0.0000123) after consideration of PI. Conclusion Based on simulation results, there would be a negligible HIV residual risk associated with the removal of a time-based MSM deferral without quarantine for source plasma incorporating PI.

BackgroundEmerging evidence suggests that COVID-19 vaccination decreases the sensitivity of anti-nucleocapsid (N) serologies, making them less reliable to assess recently-acquired infections. We therefore developed and tested a new approach based on the ratio of the anti-N absorbance of longitudinal samples to overcome this limitation.MethodsPreviously vaccinated repeat plasma donors provided at least one pre-infection (reference) and one post-infection (test) sample. All samples were tested using an in-house anti-N ELISA. Seropositivity was determined based on the ratio between the anti-N absorbance of the test and reference samples. The ratio approach was tested in a real-world setting during three cross-sectional serosurveys carried out among plasma donors in Québec, Canada.ResultsUsing a cut-off ratio of 1.5, the approach had a sensitivity of 95.2% among the 248 previously vaccinated and infected donors compared with 63.3% for the conventional approach. When tested in a real-world setting, the ratio-based approach yielded an adjusted seroprevalence of 27.4% (95% confidence interval [CI]=23.8%-30.9%) at the latest time point considered, compared to 15.1% (95% CI=12.2%-18.0%) for the conventional approach.ConclusionsThis article describes a new and highly-sensitive approach that captures a significantly greater proportion of vaccinated individuals with a recent history of SARS-CoV-2 infection.

BACKGROUND AND OBJECTIVES Several approaches are currently under study to contribute to efforts to allow men who have sex with men (MSM) to donate blood. One of these approaches involves implementing a programme of plasma donation for fractionation, with a quarantine period. The goal of this article is to identify the determinants of intention to participate in the plasma donation programme among MSM in Montreal, Canada. MATERIALS AND METHODS Based on the theory of planned behaviour, a questionnaire was developed to measure MSM's intention to donate plasma and identify influencing factors. A multiple linear regression analysis was conducted to identify the determinants of intention to donate plasma. RESULTS Respondents' (N = 933) intention to donate plasma in the next six months was moderate. The multiple linear regression model explained 55% (P

The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus responsible for the coronavirus disease 2019 (COVID-19) pandemic has raised concerns for programs overseeing donation and transplantation of cells, tissues, and organs (CTO) that this virus might be transmissible by transfusion or transplantation. Transplant recipients are considered particularly vulnerable to pathogens because of immunosuppression, and SARS-CoV-2 is likely to generate complications if contracted. Several signs and symptoms observed in COVID-19 positive patients reflect damage to multiple organs and tissues, raising the possibility of extrapulmonary SARS-CoV-2 infections and risk of transmission. At the beginning of the pandemic, a consensus has emerged not to consider COVID-19 positive patients as potential living or deceased donors, resulting in a global decrease in transplantation procedures. Medical decision-making at the time of organ allocation must consider safely alongside the survival advantages offered by transplantation. To address the risk of transmission by transplantation, this review summarizes the published cases of transplantation of cells or organs from donors infected with SARS-CoV-2 until January 2021 and assesses the current state of knowledge for the detection of this virus in different biologic specimens, cells, tissues, and organs. Evidence collected to date raises the possibility of SARS-CoV-2 infection and replication in some CTO, which makes it impossible to exclude transmission through transplantation. However, most studies focused on evaluating transmission under laboratory conditions with inconsistent findings, rendering the comparison of results difficult. Improved standardization of donors and CTO screening practices, along with a systematic follow-up of transplant recipients could facilitate the assessment of SARS-CoV-2 transmission risk by transplantation.

Blood operator must establish selection criteria according to the populations at risk of blood-related infections and complications. Therefore, this study aimed to assess the risks of transfusion-related acute lung injury (TRALI) and human immunodeficiency virus (HIV) associated with donations from trans persons.Donor screening data from Héma-Québec were used. The risks of TRALI and HIV were estimated based on internal data and assumptions derived from the literature. The risk was assessed under four scenarios: a most likely scenario, an optimistic scenario and two pessimistic scenarios. All scenarios assumed no prior screening for trans donors.The trans population comprised 134 donors, including 94 (70.1%) trans men. Of the 134 donors, 58 (43.3%) were deferred from donating a blood-derived product because of an ongoing gender-affirming genital surgery, and the remaining 76 (56.7%) were eligible donors. The risk of having a TRALI-causing donation, given that it comes from a trans man, was estimated at one every 115-999 years for all scenarios. The risk of having an HIV-contaminated donation, given that it comes from a trans woman, was estimated at one every 1881-37,600 years for all scenarios.This study suggests that donations from trans persons are associated with a negligible risk of TRALI and HIV.

The last economic evaluation of pathogen reduction technology (PRT) in Canada was conducted in 2007. We reassessed the cost-effectiveness of PRT in the province of Québec (which has its own blood supplier) and included an evaluation of the potential impact of emerging pathogens on cost-effectiveness.Decision analytic Markov models were developed to simulate the costs and quality-adjusted life-years (QALY) associated with PRT as an addition to existing safety measures for plasma and platelet products (except for bacterial culture). Models accounted for several infectious and noninfectious transfusion reactions, recipients' productivity losses ensuing from these reactions, and the impact of PRT on platelet function. Scenario analyses were conducted to evaluate the impact of a new highly contagious human immunodeficiency virus (HIV)-like or West Nile virus (WNV)-like pathogen, assuming various epidemiological scenarios.In the base case, the incremental cost-effectiveness ratio (ICER) of PRT was estimated at $8,088,974/QALY gained. Assuming the presence of an HIV-like pathogen, the ICER was $265,209/QALY gained in the "average transmission" scenario, $1,274,445/QALY gained in the "rapid testing scenario," and $123,063/QALY gained in the "highly contagious" scenario. Assuming the presence of a WNV-like pathogen, the ICER was $7,469,167/QALY gained in the "average transmission" scenario and $6,652,769/QALY gained in the "highly contagious" scenario.The cost-effectiveness of PRT may substantially improve in the event of a new, blood-borne pathogen. Given their significant impact on cost-effectiveness, the emergence of new pathogens should be considered when deciding whether to adopt PRT.

Children whose mothers have autoimmune disease may be at risk of developing immune-mediated disorders. We assessed the association between maternal autoimmune disease and risk of autoimmune disease, allergy, and cancer in offspring.We analyzed a cohort of 1,011,623 children born in Canada between 2006 and 2019. We identified mothers who had autoimmune diseases and assessed hospitalizations for autoimmune disease, allergy, and cancer in offspring between birth and 14 years of age. We estimated hazard ratios (HR) for the association of maternal autoimmune disease with child hospitalization in adjusted Cox regression models. We used within-sibling analysis to control for genetic and environmental confounders.A total of 20,354 children (2.0%) had mothers with an autoimmune disease. Compared with no autoimmune disease, maternal autoimmune disease was associated with the risk of childhood hospitalization for autoimmune disease (HR 1.96, 95% CI 1.66-2.31) and allergy (HR 1.30, 95% CI 1.21-1.40), but was not significantly associated with cancer (HR 1.31, 95% CI 0.96-1.80). Type 1 diabetes, celiac disease, inflammatory arthritis, and systemic lupus erythematosus were among specific maternal autoimmune diseases most strongly associated with childhood hospitalization for autoimmune disease and allergy. The associations disappeared after controlling for genetic and environmental confounders in the within-sibling analysis.Maternal autoimmune disease is associated with an increased risk of autoimmune disease and allergy hospitalization in offspring, but the relationship appears to be confounded by genetic and environmental factors. Prenatal exposure to immunologic or pharmacologic products is not likely a direct cause of immune-mediated disease in children.

PurposeLong-term humoral immunity to COVID-19 is not well understood owing to the continuous emergence of new variants of concern, the evolving vaccine- and infection-induced immunity, and the limited follow-up of previous studies. As the blood service in Québec (Canada), we established in April 2021 a COVID-19-focused biobank.ParticipantsAs of January 2022, included 86,229 plasma samples from 15,502 regular donors (age range=18-84 years, female %=49.7%), for an average of 5.6 donations per donor. Nearly two thirds (65.6%) of biobank donors made at least 2 donations, with many donors having provided samples pre- and post-vaccination (3061 [19.75%]) or pre- and post-infection (131 [0.85%]), thus allowing longitudinal studies on vaccine- and infection-induced immunity.Findings to dateComparative analysis of the immune response after the first and second dose of the BNT162b2 COVID-19 vaccine among SARS-CoV-2 naïve and previously infected individuals revealed that a single vaccine dose administered to previously infected individuals yields a maximal immune response. In contrast, SARS-CoV-2 naïve individuals required two vaccine doses to produce a maximal immune response. Furthermore, the results of a four-phase seroprevalence study indicate that the anti-N antibody response wanes quite rapidly, so that up to one third of previously infected donors were seronegative for anti-N.Future plansThis plasma biobank from frequent and motivated donors, and the longitudinal nature of the biobank, will provide valuable insights into the anti-SARS-CoV-2 immune response and its persistence in time, and the effect of vaccination and of viral variants on the specificity of the antiSARS-CoV-2 immune response.Strengths and LimitationsThe herein described biobank has several strengths. To the best of our knowledge, this would be the largest biobank of plasma samples dedicated to COVID-19 research, with >80,000 samples from >15,000 donors and new samples continually being added until at least December 2022. Furthermore, the large subset of donors with ≥2 samples (65.6%) – along with the high frequency of donations in this subset (i.e., median: once every 29.0 days) – enables the conduct of longitudinal analyses on COVID-19 immunity. Another strength is that donors provided a broad consent, which allows researchers to recontact them for other projects (e.g., supplemental questionnaire). Lastly, the cost of establishing the biobank was minimized since the infrastructure and personnel required for sample collection were already in place at our blood collection sites. Given these strengths, our biobank may serve as a model for other blood operators and government partners who would be interested in reproducing our initiative elsewhere.Certain limitations should nonetheless be considered when using our biobank samples. First, only plasma samples are available, such that the biobank cannot be used to study cell-based immunity. Researchers interested in studying cell-based immunity may want to contact BCQ19, which routinely collects peripheral blood mononuclear cells.[1] Second, despite the large sample, the plasma donor population is not fully representative of the overall Québec population, as expected since plasma donors are typically more representative of the healthy adult population. All exclusion criteria for plasma donations were also exclusion criteria for the biobank including immunodeficiencies, active infection, recent cancer among other chronic diseases. Third, the database associated with our biobank does not include information on disease severity, such as hospitalization or intensive care unit admission. Fourth, the database does not include information on socioeconomic status, such as income and education. However, the six-digit zip code can be used to generate a proxy index for socioeconomic status.

Canadian hematology residents are required to demonstrate competencies in transfusion medicine by the end of their 2-year training. Prior evaluation of final year trainees revealed significant variation in knowledge. To address the lack of standardization in serology teaching, an online educational immunohematology resource was created and evaluated.All Canadian post-graduate trainees completing a residency program in adult hematology during the 2018/2019 academic year were invited to participate. Only trainees from one university were exposed to the program curriculum. A validated exam was administered to trainees at both exposed and unexposed sites at the start of the academic year as a pre-test and in the following year as a post-test. The effectiveness of the program was assessed by both comparing the degree of improvement from pre- to post-test, and by comparing performance on the post-test.57 trainees from 13 universities completed the pre-test, and 45 trainees from 14 universities completed the post-test. A strong trend towards better performance in the exposed vs non-exposed trainees on the post-test was observed, and the difference was more pronounced, and statistically significant, when analysis was limited to two questions relating to interpretation of an antibody investigation panel.LearnSerology.ca is effective and may be potentially superior to traditional immunohematology teaching. The interactive capability of the platform can improve skills related to the resolution of red cell antibody panels.

We previously estimated the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies following the first pandemic wave at 2.23% in Québec, Canada. Following the much bigger second wave in fall 2020 and early 2021, we estimated the seroprevalence of anti-SARS-CoV-2 in Québec during the first months of 2021.Blood samples from regular, asymptomatic (for ≥ 14 days) donors were collected between January 25, 2021 and March 11, 2021. Anti-SARS-CoV-2 seropositivity was assessed using an enzyme-linked immunosorbent assay that captures antibodies directed against the receptor binding domain of the SARS-CoV-2 spike (and hence cannot discriminate between infection- and vaccine-induced seropositivity). Seroprevalence estimates were adjusted for regional distribution, age, and sex.Samples from 7924 eligible donors were analyzed, including 620 (7.8%) vaccinated donors and 7046 (88.9%) unvaccinated donors (vaccination status unknown for 258 (3.3%) donors). Overall, median age was 51 years; 46.4% of donors were female. The adjusted seroprevalence was 10.5% (95% CI = 9.7-11.3) in the unvaccinated population and 14.7% (95% CI = 13.8-15.6) in the overall population. Seroprevalence gradually decreased with age and was higher among donors who self-identified as having a racial/ethnic background other than white, both in the overall and in the unvaccinated populations.The seroprevalence of SARS-CoV-2 antibodies significantly increased in Québec since spring 2020, with younger persons and ethnic minorities being disproportionately affected. When compared with the cumulative incidence rate reported by public health authorities (i.e., 3.3% as of March 11, 2021), these results suggest that a substantial proportion of infections remain undetected despite improvements in access to COVID-19 testing.RéSUMé: OBJECTIFS: Lors d’une première étude, nous avons estimé la séroprévalence des anticorps contre le syndrome respiratoire aigu sévère coronavirus 2 (SRAS-CoV-2) après la première vague pandémique à 2,23 % au Québec, Canada. Cette seconde étude estime la séroprévalence de l’anti-SRAS-CoV-2 au Québec lors de la deuxième vague pandémique. MéTHODES: Des échantillons de donneurs de sang asymptomatiques (≥ 14 jours) ont été prélevés entre le 25 janvier et le 11 mars 2021. La séropositivité a été évaluée à l’aide d’un dosage immuno-enzymatique qui capture les anticorps dirigés contre la protéine Spike du récepteur de domaine de liaison du SARS-CoV-2 (et ne peut donc distinguer l’immunité induite par l’infection et la vaccination). La séroprévalence a été ajustée en fonction de l’âge et du sexe par région. RéSULTATS: Des échantillons de 7 924 donneurs ont été analysés, dont 620 (7,8 %) étaient vaccinés et 7 046 (88,9 %) étaient non vaccinés (statut vaccinal inconnu pour 258 (3,3 %) donneurs). Dans l’ensemble, l’âge médian était de 51 ans et 46,4 % des donneurs étaient des femmes. La séroprévalence ajustée était de 10,5 % (IC 95 % = 9,7 à 11,3) dans la population non vaccinée et de 14,7 % (IC 95 % = 13,8 à 15,6) dans la population globale. La séroprévalence diminuait progressivement avec l’âge et était plus élevée chez les donneurs d’origine ethnique autre que blanche. CONCLUSION: La séroprévalence anti-SRAS-CoV-2 a considérablement augmenté au Québec depuis le printemps 2020, les personnes plus jeunes et les minorités ethniques étant plus touchées. Comparés au taux d’incidence cumulatif signalé par la santé publique (c.-à-d. 3,3 % au 11 mars 2021), ces résultats suggèrent qu’une proportion importante d’infections reste non détectée.

Background:Banked human milk (BHM) has inherent infectious risks, even when pasteurized. Because of the ubiquity ofBacillus cereusin the environment and its ability to resist the Holder pasteurization process, there is a concern that BHM might lead to severeB. cereusinfections.Objective:We reviewed observed and published cases to determine the potential causal role of BHM as the source of these infections.Methods:Two infants in the province of Québec (Canada) developed aB. cereusneonatal infection, and both had received BHM. We conducted bacteriological studies to compare clinical isolates and those found in these cases.Results:After extended culture of BHM retention lots,B. cereuswas found to have been involved in batches related to the first case. However, molecular typing showed that the strain was different from the clinical isolate, therefore excluding BHM as the source of contamination. In the second case, aBrevibacillusspp was isolated, a species distinct from the clinical isolate.Conclusion:Based on these cases and others reported in the literature, a causal link betweenB. cereuscontaminated BHM and preterm neonatal infection has never been documented. Therefore, the risk that BHM can cause this infection remains theoretical. Given the widespread presence ofB. cereusin the hospital environment and its capacity to resist standard cleaning procedures, it seems likely that airborne or direct or indirect contact are the main sources of most, if not all, cases of severeB. cereusneonatal infections, even in babies exposed to BHM.

Background The determination of the RhD phenotype is crucial to avoid alloimmunization, especially in childbearing women. Following the 2015 recommendation from the Work Group on RHD Genotyping, a large-scale RHD genotyping program was implemented in the province of Quebec (Canada) and offered to women ≤45 years old with a serological weak D or discordant results. Since weak D type 42 was previously shown to be prevalent among French Canadians, genotyping for that variant was also performed. Our aim was to report the prevalence of the weak D alleles in the province of Quebec. Study design and methods A retrospective study of 2105 women with serological weak D referred to Hema-Quebec's immunohematology reference laboratory (IRL) between June 2016 and May 2020 was conducted. Results from the serological tests performed by the referring hospital were compiled and RHD were genotyped. Results Most patients presented at least one serological result ≤2+ before being referred to Hema-Quebec. Weak D type 42 was the most prevalent variant, representing 17.5% (368/2105) of all individuals tested. Only 15.3% (323/2105) of patients were weak D type 1, 3.3% (69/2105) were type 2, and 8.6% (180/2105) were type 3. Weak D type 42 is highly expressed in regions with low immigration rate and known for their founder effect. Conclusion Our RHD genotyping program allowed for a better management of weak D. The province of Quebec presents a unique RHD genotype distribution. We confirmed that weak D type 42 is associated with a founder effect found in Caucasian French Canadians.

IntroductionChildhood overweight and obesity (OWO) is a primary global health challenge. Childhood OWO prevention is now a public health priority in China. The Sino-Canadian Healthy Life Trajectories Initiative (SCHeLTI), one of four trials being undertaken by the international HeLTI consortium, aims to evaluate the effectiveness of a multifaceted, community-family-mother-child intervention on childhood OWO and non-communicable diseases risk.Methods and analysisThis is a multicentre, cluster-randomised, controlled trial conducted in Shanghai, China. The unit of randomisation is the service area of Maternal Child Health Units (N=36). We will recruit 4500 women/partners/families in maternity and district level hospitals. Participants in the intervention group will receive a multifaceted, integrated package of health promotion interventions beginning in preconception or in the first trimester of pregnancy, continuing into infancy and early childhood. The intervention, which is centred on a modified motivational interviewing approach, will target early-life maternal and child risk factors for adiposity. Through the development of a biological specimen bank, we will study potential mechanisms underlying the effects of the intervention. The primary outcome for the trial is childhood OWO (body mass index for age ≥85th percentile) at 5 years of age, based on WHO sex-specific standards. The study has a power of 0.8 (α=0.05) to detect a 30% risk reduction in the proportion of children with OWO at 5 years of age, from 24.4% in the control group to 17% in the intervention group. Recruitment was launched on 30 August 2018 for the pilot study and 10 January 2019 for the formal study.Ethics and disseminationThe study has been approved by the Medical Research Ethics Committee of the International Peace Maternity and Child Health Hospital in Shanghai, China, and the Research Ethics Board of the Centre Intégré Universitaire de Santé et Services Sociaux de l’Estrie–CHUS in Sherbrooke, Canada. Data sharing policies are consistent with the governance policy of the HeLTI consortium and government legislation.Trial registration numberChiCTR1800017773.Protocol versionNovember 11, 2020 (Version #5).

IntroductionThe SARS-CoV-2 pandemic has put significant additional pressure on healthcare systems throughout the world. The identification of at-risk population beyond age, pre-existing medical conditions and socioeconomic status has been the subject of only a small part of the global COVID-19 research so far. To this day, more data is required regarding the association between HLA allele and red blood cell (RBC) antigens’ expression in regard to SARS-CoV-2 infection susceptibility and virus clearance capability, and COVID-19 susceptibility, severity, and duration.MethodsThe phenotypes for ABO and RhD, and the genotypes for 37 RBC antigens and HLA-A, B, C, DRB1, DQB1 and DPB1 were determined using high throughput platforms (Luminex and Next-generation Sequencing) in 90 Caucasian convalescent plasma donors. The results were compared to expected reference frequencies, local and international databases, and literature.ResultsThe AB group was significantly increased (1.5x, p=0.018) and a non-significant (2.2x, p=0.030) increase was observed for the FY*A allele frequency in the convalescent cohort (N=90) compared to reference frequencies. Some HLA alleles were found significantly overrepresented (HLA-B*44:02, C*05:01, DPB1*04:01, DRB1*04:01 and DRB1*07:01) or underrepresented (A*01:01, B51:01 and DPB1*04:02) in convalescent individuals compared to the local bone marrow registry population.ConclusionOur study of infection-susceptible but non-hospitalized Caucasian COVID-19 patients contributes to the global understanding of host genetic factors associated with SARS-CoV-2 infection susceptibility and severity of the associated disease.

BACKGROUND AND OBJECTIVES: Access to large pools of healthy adult donors advantageously positions blood component providers to undertake anti-SARS-CoV-2 seroprevalence studies. While numerous seroprevalence reports have been published by blood operators during the COVID-19 pandemic, details on the assay used has not been well documented. The objectives of this study were to evaluate the diversity of assays being used by blood operators and assess how this may affect seroprevalence estimates.MATERIALS AND METHODS: We surveyed 49 blood component providers from 39 countries. Questionnaire included information on the number and identity of assays used, the detected immunoglobulin(s) and target antigen, and performance characteristics (sensitivity, specificity).RESULTS: Thirty-eight of the 49 contacted blood suppliers provided at least partial responses. The results indicate that 19 commercial and five in-house serology assays have been used by surveyed blood operators. The Abbott SARS-CoV-2 IgG assay was the most commonly used kit and utilized by 15 blood suppliers. Two assays did not detect IgG, but detected either IgM/IgA or IgM. 68·2% of assays targeted the spike protein and 50% the nucleocapsid protein, while 18·2% targeted both viral proteins. The sensitivity and specificity of IgG-specific assays ranged from 71·9% to 100% and from 96·2% to 100%, respectively. As of 18 October 2020, the seroprevalence was below 5% in 10 of 14 countries reporting.CONCLUSION: Our results highlight the diversity of assays being used. Analyses comparing blood donor seroprevalence across countries should consider assay characteristics with optimization of signal/cut-off ratios and consistent methodology to adjust for waning antibody.

A substantial proportion of individuals infected with SARS-CoV-2 do not experience noticeable symptoms typical of COVID-19. Our objectives were to evaluate the impact of the first wave of the pandemic in Québec by measuring SARS-CoV-2 antibody seroprevalence in a convenience sample of healthy blood donors and to study the association between seropositivity and the occurrence of COVID-19 symptoms.The study design was a cross-sectional serological survey with a nested case-control study. Residual blood samples from donations collected between May 25 and July 9, 2020 (well before vaccination rollout) in the province of Québec were tested for anti-Spike RBD antibodies by ELISA. Seropositive donors and a control group of seronegative donors were questioned about prior COVID-19 symptoms. All qualified blood donors were eligible for participation.A total of 7691 blood donors were included in the study. After adjustments, the seroprevalence rate was 2.2% (95% CI 1.9-2.6). Seropositive donors reported one or more symptoms in a proportion of 52.2% (95% CI 44.2-60.1); this proportion was 19.1% (95% CI 13.4-26.1) among seronegative donors, suggesting that approximately 50-66% of all infections were asymptomatic. Univariate analysis of associations between symptoms and seropositivity revealed that except for rhinorrhea, all symptoms were significantly associated with seropositivity.Assuming that blood donors are fairly representative of the general adult population, this study shows that less than 3% of 18-69-year-olds have been infected during the first wave of the pandemic in the province of Québec. Our data also confirm that many infections escaped detection, including a substantial proportion that were asymptomatic.RéSUMé: OBJECTIFS: Une proportion substantielle de personnes infectées par le SRAS-CoV-2 ne présentent pas de symptômes visibles typiques de la COVID-19. Nos objectifs étaient d’évaluer l’impact de la première vague de la pandémie au Québec en mesurant la séroprévalence des anticorps anti-SRAS-CoV-2 chez les donneurs de sang en bonne santé, et d’étudier l’association entre la séropositivité et la survenue des symptômes de la COVID-19. MéTHODES: Le design de l’étude était une enquête de sérologie transversale avec une étude cas-témoins nichée dans la cohorte. Des échantillons de sang provenant de dons recueillis entre le 25 mai et le 9 juillet 2020 (bien avant le déploiement de la vaccination) dans la province de Québec ont été testés pour les anticorps anti-spicule RBD (Receptor Binding Domain) par ELISA. Les donneurs séropositifs et un groupe témoin de donneurs séronégatifs ont été interrogés sur les symptômes spécifiques à la COVID-19. Tous les donneurs qualifiés pour le don de sang étaient éligibles à participer à l’étude. RéSULTATS: Au total, 7 691 donneurs de sang ont été inclus dans l’étude. Après ajustements, le taux de séroprévalence était de 2,2 % (IC à 95% 1,9–2,6). Les donneurs séropositifs ont signalé un ou plusieurs symptômes dans une proportion de 52,2 % (IC à 95% 44,2–60,1); cette proportion était de 19,1 % (IC à 95% 13,4–26,1) parmi les donneurs séronégatifs, ce qui suggère qu’entre 50 % et 66 % de toutes les infections étaient asymptomatiques. Une analyse univariée des associations entre les symptômes et la séropositivité a révélé qu’à l’exception de la rhinorrhée, tous les symptômes étaient significativement associés à la séropositivité. CONCLUSION: En supposant que les donneurs de sang sont assez représentatifs de la population adulte générale, cette étude montre que moins de 3 % des 18–69 ans ont été infectés lors de la première vague de la pandémie dans la province du Québec. Nos données confirment également que de nombreuses infections n’ont pas fait l’objet d’un test moléculaire de dépistage, y compris une proportion importante qui était asymptomatique.

Background The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) virus is the cause of the ongoing coronavirus disease 2019 (COVID‐19) pandemic, infecting millions of people and causing more than two million deaths. The SARS‐CoV‐2 Spike glycoproteins mediate viral entry and represent the main target for antibody responses. Humoral responses were shown to be important for preventing and controlling infection by coronaviruses. A promising approach to reduce the severity of COVID‐19 is the transfusion of convalescent plasma. However, longitudinal studies revealed that the level of antibodies targeting the receptor‐binding domain (RBD) of the SARS‐CoV‐2 Spike declines rapidly after the resolution of the infection. Study Design and Methods To extend this observation beyond the RBD domain, we performed a longitudinal analysis of the persistence of antibodies targeting the full‐length SARS‐CoV‐2 Spike in the plasma from 15 convalescent donors. We generated a 293T cell line constitutively expressing the SARS‐CoV‐2 Spike and used it to develop a high‐throughput flow cytometry‐based assay to detect SARS‐CoV‐2 Spike‐specific antibodies in the plasma of convalescent donors. Results and Conclusion We found that the level of antibodies targeting the full‐length SARS‐CoV‐2 Spike declines gradually after the resolution of the infection. This decline was not related to the number of donations but strongly correlated with the decline of RBD‐specific antibodies and the number of days post‐symptom onset. These findings help to better understand the decline of humoral responses against the SARS‐CoV‐2 Spike and provide important information on when to collect plasma after recovery from active infection for convalescent plasma transfusion.