SARS-CoV-2 antibody kinetics in blood donors with a previously positive SARS-CoV-2 antibody test within a seroprevalence survey.

The persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is a matter of importance regarding the coronavirus disease 19 (COVID-19) pandemic. To observe antibody dynamics, 105 blood donors, positive for SARS-CoV-2 antibodies by a lateral flow test within a seroprevalence study, were included in this study. Thirty-nine (37%) of 105 the donors were confirmed positive by a total Ig Wantai enzyme-linked immunosorbent assay (ELISA). Three (8%) in this group of 39 reported severe and 26/39 (67%) mild to moderate COVID-19 symptoms. By further ELISA-testing, 33/39 (85%) donors were initially positive for IgG antibodies, 31/39 (79%) for IgA, and 32/39 (82%) for IgM, while 27/39 (69%) were positive for all three isotypes. Persistence of IgG, IgA, and IgM was observed in 73%, 79%, and 32% of donors, respectively, after 6-9 months of observation. For IgM antibodies, the decline in the proportion of positive donors was statistically significant (p = 0.002) during 12 months observation, for IgG only the decline at 3 months was statistically significant (p = 0.042). Four donors exhibited notable increases in antibody levels. In conclusion, persistent SARS-CoV-2 IgA antibodies and IgG antibodies at 6-9 months are present in approximately three of four individuals with previous mild to moderate COVID-19.

Estimating SARS-CoV-2 Seroprevalence in Canadian Blood Donors, April 2020 to March 2021: Improving Accuracy with Multiple Assays.

We have previously used composite reference standards and latent class analysis (LCA) to evaluate the performance of laboratory assays in the presence of tarnished gold standards. Here, we apply these techniques to repeated, cross-sectional study of Canadian blood donors, whose sera underwent parallel testing with four separate SARS-CoV-2 antibody assays. We designed a repeated cross-sectional design with random cross-sectional sampling of all available retention samples (n = 1500/month) for a 12 -month period from April 2020 until March 2021. Each sample was evaluated for SARS-CoV-2 IgG antibodies using four assays an Abbott Architect assay targeting the nucleocapsid antigen (Abbott-NP, Abbott, Chicago IL) and three in-house IgG ELISAs recognizing distinct recombinant viral antigens: full-length spike glycoprotein (Spike), spike glycoprotein receptor binding domain (RBD) and nucleocapsid (NP). We used two analytic approaches to estimate SAR-CoV-2 seroprevalence: a composite reference standard and LCA. Using LCA to estimate true seropositivity status based on the results of the four antibody tests, we estimated that seroprevalence increased from 0.8% (95% CI: 0.5-1.4%) in April 2020 to 6.3% (95% CI: 5.1-7.6%) in March 2021. Our study provides further support for the use of LCA in upcoming public health crises, epidemics, and pandemics when a gold standard assay may not be available or identifiable. IMPORTANCE Here, we describe an approach to estimating seroprevalence in a low prevalence setting when multiple assays are available and yet no known gold standard exists. Because serological studies identify cases through both diagnostic testing and surveillance, and otherwise silent, unrecognized infections, serological data can be used to estimate the true infection fatality ratio of a disease. However, seroprevalence studies rely on assays with imperfect sensitivity and specificity. Seroreversion (loss of antibody response) also occurs over time, and with the advent of vaccination, distinction of antibody response resulting from vaccination as opposed to antibody response due to infection has posed an additional challenge. Our approach indicates that seroprevalence on Canadian blood donors by the end of March 2021was less than 10%. Our study supports the use of latent class analysis in upcoming public health crises, epidemics, and pandemics when a gold standard assay may not be available or identifiable.

SARS-CoV-2 Virus-Like Particle Neutralizing Capacity in Blood Donors Depends on Serological Profile and Donor-Declared SARS-CoV-2 Vaccination History.

This study attempted to understand the levels of neutralizing titers and the breadth of antibody protection against wild-type and variant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Canadian blood donors during the first 3 months of 2021. During this period, it is unlikely that many of the blood donors had received a second dose, since vaccine rollout had not yet ramped up, and less than 2% of the Canadian population had received a second dose of vaccine. A repeated cross-sectional design was used. A random cross-sectional sampling of all available Canadian Blood Services retention samples (n = 1,500/month) was drawn monthly for January, February, and March 2021. A tiered testing approach analyzed 4,500 Canadian blood donor specimens for potential evidence of a signal for anti-spike (anti-S), anti-receptor-binding domain (anti-RBD), and anti-nucleocapsid protein (anti-N). Specimens were stratified based on donor-declared vaccination history and then stratified on the presence or absence of anti-N as follows: (i) "vaccinated plus anti-N" (n = 5), (ii) "vaccinated and no anti-N" (n = 20), (iii) "unvaccinated plus anti-N" (n = 20), and (iv) "unvaccinated and no anti-N" (n = 20). Randomized specimens were then characterized for neutralizing capacity against wild-type as well as SARS-CoV-2 variants of concern (VOCs) (Alpha [B.1.1.7], Beta [B.1.351], Gamma [P.1], and Delta [B.1.617.2]) using S-pseudotyped virus-like particle (VLP) neutralization assays. There was no neutralizing capacity against wild-type and VOC VLPs within the "no vaccine and no anti-N" group. Neutralization of Beta VLPs was less than wild-type VLPs within "vaccinated plus anti-N," "vaccinated and no anti-N", and "unvaccinated plus anti-N" groups. IMPORTANCE In the first 3 months of 2021 as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination was in the initial stages of a mass rollout, Canadian blood donors had various levels of humoral protection against wild-type and variant of concern (VOC) SARS-CoV-2. Very few Canadians would have received a second dose of a SARS-CoV-2 vaccine. In this study, we identified elevated levels of neutralizing capacity, albeit with reduced neutralization capacity against one or more SARS-CoV-2 strains (wild type and VOCs) in vaccinated blood donors. This broad neutralizing response we present regardless of evidence of natural SARS-CoV-2 infection. Neutralizing capacity against wild type and VOCs varied significantly within the unvaccinated group, with one subset of unvaccinated plasma specimens (unvaccinated and no anti-N) having no measurable wild type- nor variant-neutralizing capacity. The study is important because it indicates that vaccination can be associated with a broad neutralizing antibody capacity of donor plasma against SARS-CoV-2 VOCs.

Impact of COVID-19 on Blood Donation and Supply: A Multicenter Cross-Sectional Study from Saudi Arabia.

BACKGROUND: The coronavirus disease-19 (COVID-19) pandemic caused a major impact on blood donation process and supply globally. A lockdown management procedure was launched nationally in Saudi Arabia to manage this global health crisis. The main aim of this study was to determine the effect of COVID-19 lockdown on blood donation services and supply in different regions of Saudi Arabia. Study Design and Methods. A retrospective cross-sectional study was conducted in the blood bank centers of 5 major cities including Riyadh, Jeddah, Dammam, Hail, and Jizan in Saudi Arabia. Demographic and blood characteristics were retrieved from the first 6 months of 2019 (January-June) and compared to the same period of 2020. RESULTS: Our findings showed variation in the characteristics of blood donation and supply among the centers surveyed, as some of these centers were adversely affected, while others showed an increase in the availability of blood products during the pandemic. For example, Jeddah's center was significantly affected by COVID-19 lockdown whereas Hail's center showed a significant increase in the analyzed characteristics of blood donation services in 2020 compared to 2019. Overall, there was no major difference among the surveyed centers between 2020 and 2019, and this might be due to the effective management of blood supply and transfusion. Discussion. Although blood supply and transfusion practice was slightly affected at various degree among the surveyed centers, the whole process did not show a significant effect on the overall outcome. This is in fact due to the proper preparedness, management of blood requirements and supplies, and efficient response of the surveyed centers in Saudi Arabia.

Prevalence of COVID-19 among blood donors: The Jordan University of Science and Technology experience.

ABSTRACT: The corona virus disease-19 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, had health and economic results that profoundly affected communities worldwide. Investigating the seroprevalence of SARS-Cov-2 in blood donors is of a significant clinical and scientific value as it adds to knowledge about local herd immunity levels.To study the prevalence of SARS-Cov-2 infection among blood donors at a tertiary referral hospital in the north of Jordan.This is a prospective study that included all blood donors between September 2020 and March 2021. Donors' IgG antibodies were qualitatively immunoassayed to determine the antibody status against SARS-CoV-2. The Elecsys Anti-SARS-CoV-2 technique was utilized.One thousand samples were tested by total antibody against SARS-CoV-2. The median age was 29 years, 96.7% were males. The seroprevalence was 14.5%, and 80% of the positive participants did not report previous COVID-19 infection. The seroprevalence of COVID-19 antibodies was less among smokers and those with an O blood group and higher among donors with an AB blood group.The prevalence of COVID-19 among healthy young blood donors at a tertiary teaching health facility in the north of Jordan was 14.5%. Smokers and those with an O blood group were less likely to be seropositive, as opposed to donors with an AB blood group.

Seroprevalence of anti-SARS-CoV-2 among blood donors in Rio de Janeiro, Brazil.

OBJECTIVE To estimate the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the state of Rio de Janeiro, Brazil. METHODS Data were collected on 2,857 blood donors from April 14 to 27, 2020. This study reports crude prevalence of antibodies to SARS-CoV-2, population weighted prevalence for the state, and prevalence adjusted for test sensitivity and specificity. Logistic regression models were used to establish the correlates of SARS-CoV-2 prevalence. For the analysis, we considered collection period and site, sociodemographic characteristics, and place of residence. RESULTS The proportion of positive tests for SARS-Cov-2, without any adjustment, was 4.0% (95%CI 3.3-4.7%), and the weighted prevalence was 3.8% (95%CI 3.1-4.5%). We found lower estimates after adjusting for test sensitivity and specificity: 3.6% (95%CI 2.7-4.4%) for the non-weighted prevalence, and 3.3% (95%CI 2.6-4.1%) for the weighted prevalence. Collection period was the variable most significantly associated with crude prevalence: the later the period, the higher the prevalence. Regarding sociodemographic characteristics, the younger the blood donor, the higher the prevalence, and the lower the education level, the higher the odds of testing positive for SARS-Cov-2 antibody. We found similar results for weighted prevalence. CONCLUSIONS Our findings comply with some basic premises: the increasing trend over time, as the epidemic curve in the state is still on the rise; and the higher prevalence among both the youngest, for moving around more than older age groups, and the less educated, for encountering more difficulties in following social distancing recommendations. Despite the study limitations, we may infer that Rio de Janeiro is far from reaching the required levels of herd immunity against SARS-CoV-2.

Charting elimination in the pandemic: a SARS-CoV-2 serosurvey of blood donors in New Zealand.

New Zealand has a strategy of eliminating SARS-CoV-2 that has resulted in a low incidence of reported coronavirus-19 disease (COVID-19). The aim of this study was to describe the spread of SARS-CoV-2 in New Zealand via a nationwide serosurvey of blood donors. Samples (n = 9806) were collected over a month-long period (3 December 2020-6 January 2021) from donors aged 16-88 years. The sample population was geographically spread, covering 16 of 20 district health board regions. A series of Spike-based immunoassays were utilised, and the serological testing algorithm was optimised for specificity given New Zealand is a low prevalence setting. Eighteen samples were seropositive for SARS-CoV-2 antibodies, six of which were retrospectively matched to previously confirmed COVID-19 cases. A further four were from donors that travelled to settings with a high risk of SARS-CoV-2 exposure, suggesting likely infection outside New Zealand. The remaining eight seropositive samples were from seven different district health regions for a true seroprevalence estimate, adjusted for test sensitivity and specificity, of 0.103% (95% confidence interval, 0.09-0.12%). The very low seroprevalence is consistent with limited undetected community transmission and provides robust, serological evidence to support New Zealand's successful elimination strategy for COVID-19.

Trends in blood donations, blood donors' knowledge, practices and expectations during the COVID-19 pandemic in Cameroon.

INTRODUCTION: The COVID-19 pandemic, caused by a novel coronavirus, has already affected over 99 062 people in 53 African countries and killed 3082. The pandemic threatens blood supply but we do not yet know its impact on blood donations or on the perceptions and expectations of donors. METHODS: We conducted a cross-sectional study in four hospital-based blood services in Cameroon, using a survey design and focusing on the subjective and cultural aspects of donors. Using a semi-structured questionnaire, we collected the participants' responses as to their understanding of COVID-19 and of current protection measures, and their expectations. Data on trends of blood donations were collected retrospectively for the period from 1st January to 30th April 2019 and the same period in 2020. RESULTS: Of 494 donors included, 432 (87·4%) were enrolled from fixed blood collection sites and 62 (12·6%) were contacted by phone. A total of 464 (93·9%) participants believed that the COVID-19 is a lung disease, but some declared it to be imaginary (7·7%), a foreign disease (8·3%) or a blood-borne disease (3·2%). The participants reported that the distribution of face masks and hydroalcoholic solutions (92·5%), social distancing and hygiene (6·3%) are the most important measures that need to be in place for safe donation. The number of blood donations dropped by 21·5% between 2019 and 2020. CONCLUSION: Most of the donors know COVID-19, its transmission routes and manifestations. In the absence of barrier measures, they perceive blood donation as a threat to their health. Distribution of masks and hydroalcoholic solution might motivate more donors and improve the blood supply.

Seroprevalence of SARS-CoV-2 infection in Cincinnati Ohio USA from August to December 2020.

The world is currently in a pandemic of COVID-19 (Coronavirus disease-2019) caused by a novel positive-sense, single-stranded RNA ß-coronavirus referred to as SARS-CoV-2. Here we investigated rates of SARS-CoV-2 infection in the greater Cincinnati, Ohio, USA metropolitan area from August 13 to December 8, 2020, just prior to initiation of the national vaccination program. Examination of 9,550 adult blood donor volunteers for serum IgG antibody positivity against the SARS-CoV-2 Spike protein showed an overall prevalence of 8.40%, measured as 7.56% in the first 58 days and 9.24% in the last 58 days, and 12.86% in December 2020, which we extrapolated to ~20% as of March, 2021. Males and females showed similar rates of past infection, and rates among Hispanic or Latinos, African Americans and Whites were also investigated. Donors under 30 years of age had the highest rates of past infection, while those over 60 had the lowest. Geographic analysis showed higher rates of infectivity on the West side of Cincinnati compared with the East side (split by I-75) and the lowest rates in the adjoining region of Kentucky (across the Ohio river). These results in regional seroprevalence will help inform efforts to best achieve herd immunity in conjunction with the national vaccination campaign.

SARS-CoV-2 seroprevalence among blood donors in Québec, and analysis of symptoms associated with seropositivity: a nested case-control study.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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% 1,9­2,6). Les donneurs séropositifs ont signalé un ou plusieurs symptômes dans une proportion de 52,2 % (IC à 95% 44,2­60,1); cette proportion était de 19,1 % (IC à 95% 13,4­26,1) 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 18­69 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.

Seroprevalence of Anti-SARS-CoV-2 Antibodies in Blood Donors from Nuevo Leon State, Mexico, during 2020: A Retrospective Cross-Sectional Evaluation.

The progression and distribution of the SARS-CoV-2 pandemic are continuously changing over time and can be traced by blood donors' serological survey. Here, we investigated the seroprevalence of anti-SARS-CoV-2 antibodies in blood donors in Nuevo Leon, Mexico during 2020 as a strategy for the rapid evaluation of the spread of SARS-CoV-2 and asymptomatic case detection. We collected residual plasma samples from blood donors who attended two regional donation centers from January to December of 2020 to identify changes in anti-SARS-CoV-2 IgG prevalence. Plasma samples were analyzed on the Abbott Architect instrument using the commercial Abbott SARS-CoV-2 IgG chemiluminescent assay. We found a total of 99 reactive samples from 2068 analyzed plasma samples, resulting in a raw prevalence of 4.87%. Donors aged 18-49 years were more likely to be seropositive compared to those aged >50 years (p < 0.001). Weekly seroprevalence increased from 1.8% during the early pandemic stage to 27.59% by the end of the year. Prevalence was 1.46-fold higher in females compared to males. Case geographical mapping showed that Monterrey city recorded the majority of SARS-CoV-2 cases. These results show that there is a growing trend of seroprevalence over time associated with asymptomatic infection that is unnoticed under the current epidemiological surveillance protocols.

Efficient Identification of High-Titer Anti-Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Antibody Plasma Samples by Pooling Method.

CONTEXT.­: The ongoing COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has elicited a surge in demand for serologic testing to identify previously infected individuals. In particular, antibody testing is crucial in identifying COVID-19 convalescent plasma, which has been approved by the Food and Drug Administration under the Emergency Use Authorization for use as passive immunotherapy for hospitalized patients infected with COVID-19. Currently, high-titer COVID-19 convalescent plasma can be qualified by Ortho's Vitros COVID-19 IgG antibody test. OBJECTIVE.­: To explore the use of an efficient testing method to identify high-titer COVID-19 convalescent plasma for use in treating COVID-19-infected patients and track COVID-19 positivity over time. DESIGN.­: We evaluated an enzyme-linked immunosorbent assay (ELISA)-based method that detects antibodies specific to the SARS-CoV-2 receptor binding domain (RBD) with individual and pooled plasma samples and compared its performance against the Vitros COVID-19 IgG antibody test. Using the pooled RBD-ELISA (P-RE) method, we also screened more than 10 000 longitudinal healthy blood donor samples to assess seroprevalence. RESULTS.­: P-RE demonstrates 100% sensitivity in detecting Food and Drug Administration-defined high-titer samples when compared with the Vitros COVID-19 IgG antibody test. Overall sensitivity of P-RE when compared with the Vitros COVID-19 IgG antibody test and our individual sample RBD-ELISA (I-RE) were 83% and 56%, respectively. When screening 10 218 healthy blood donor samples by P-RE, we found the seroprevalence correlated with the local infection rates with a correlation coefficient of 0.21 (P < .001). CONCLUSIONS.­: Pooling plasma samples can be used to efficiently screen large populations for individuals with high-titer anti-RBD antibodies, important for COVID-19 convalescent plasma identification.

Low prevalence of antibodies against SARS-CoV-2 among voluntary blood donors in Guangzhou, China.

Since the first case of COVID-19 reported in late December of 2019 in Wuhan, China, the SARS-CoV-2 virus has caused approximately 20 million infections and 732 thousand deaths around the world by 11 August 2020. Although the pathogen generally infects the respiratory system, whether it is present in the bloodstream and whether it poses a threat to the blood supply during the period of the outbreak is of serious public concern. In this study, we used enzyme-linked immunosorbent assay (ELISA) to screen total antibodies against SARS-CoV-2 in 2199 blood donors, who had donated blood at the Guangzhou Blood Center during the epidemic. The Ig-reactive samples were further characterized for IgA, IgG, and IgM subtypes by ELISA and viral nucleic acid by real-time polymerase chain reaction. Among the 2199 plasma samples, seven were reactive under total antibodies' screening. Further testing revealed that none of them had detectable viral nucleic acid or IgM antibody, but two samples contained IgA and IgG. The IgG antibody titers of both positive samples were 1:16 and 1:4, respectively. Our results indicated a low prevalence of past SARS-CoV-2 infection in our blood donors, as none of the tests were positive for viral nucleic acid and only 2 out of 2199 (0.09%) of samples were positive for IgG and IgA. There would be a limited necessity for the implementation of such testing in blood screening in a COVID-19 low-risk area.

Deterrents in recruitment of COVID-19 convalescent plasma donors: Experience from a hospital-based blood centre in India.

INTRODUCTION: Recruitment of Covid-19 convalescent plasma (CCP) donors may present as a challenge due to inexperience and differences in donor profile as compared to whole blood donation. Present study highlights the deterrents to recruiting CCP donors at a hospital based blood centre. MATERIALS AND METHODS: Potential CCP donors were contacted individually by telephone and a group approach through camp organisers from May to July 2020. Recruitment challenges were noted and deferrals of these recruited donors during screening and medical examination was obtained and analysed. RESULTS: Total 1165 potential CCP donors were contacted. Around 47% donors were lost due to challenges related to information storage and retrieval. Fear of health, family pressure, and fear of a new procedure were major reason (27.2%) for unwillingness to donate. The main reasons for deferral among potential donors were multiparity (38%) and being overage/underage (31.6%). Finally, 468 donors were recruited including 408 by individual approach and 60 by a group approach. From these absence of detectable COVID-19 antibodies were found in 15.4%. Few donors (9.0%) were deferred as they had not completed 28 days post recovery. CONCLUSION: The process of CCP donor recruitment differs from that of whole blood donation and requires an individualised approach with involvement of clinicians in the initial phases of the pandemic. A group approach targeting specific organisations could be adopted for a successful CCP collection program. There is a need to relook into some aspects of donor selection such as consideration of multiparous female donors and overage/underage donors after reviewing scientific evidence.

Intra-operative autologous blood donation for cardiovascular surgeries in Japan: A retrospective cohort study.

Intra-operative autologous blood donation is a blood conservation technique with limited evidence. We evaluated the association between intra-operative autologous blood donation and decrease in peri-operative transfusion in cardiovascular surgery based on evidence from a Japanese administrative database. We extracted the data of patients who had undergone cardiovascular surgery from the Diagnosis Procedure Combination database in Japan (2016-2019). Based on the surgery type, we examined the association of intra-operative autologous blood donation with the transfusion rate and amount of blood used in cardiac and aortic surgeries using multilevel propensity score matching. We enrolled 32,433 and 4,267 patients who underwent cardiac and aortic surgeries and received 5.0% and 6.7% intra-operative autologous blood donation with mean volumes of 557.68 mL and 616.96 mL, respectively. The red blood cell transfusion rates of the control and intra-operative autologous blood donation groups were 60.6% and 38.4%, respectively, in the cardiac surgery cohort (p < .001) and 91.4%, and 83.8%, respectively, in the aortic surgery cohort (p = .037). The transfusion amounts for the control and intra-operative autologous blood donation groups were 5.9 and 3.5 units of red blood cells, respectively, for cardiac surgery patients (p < .001) and 11.9 and 7.9 units, respectively, for aortic surgery patients (p < .001). Intra-operative autologous blood donation could reduce the transfusion rate or amount of red blood cells and fresh frozen plasma for patients undergoing index cardiovascular surgery and could be an effective blood transfusion strategy in cardiovascular surgery for Japanese patients.

Seroprevalence of SARS-Coronavirus 2 among asymptomatic healthy blood donors from healthcare and non-healthcare settings: Implications for safety of blood donors and blood collection staff during blood donation.

INTRODUCTION: SARS-Coronavirus-2 pandemic has adversely affected blood supply as potential blood donors were afraid of acquiring infection in hospital settings. We aimed to compare COVID-19 seroprevalence among asymptomatic blood donors from healthcare and non-healthcare setting to analyse the difference in exposure level of each group as well as the risk of acquiring infection during the process of blood donation. MATERIAL AND METHODS: Analysis of whole blood donors tested for SARS-CoV-2 IgG antibodies was carried out after categorizing them into healthcare workers (HCW) and non-healthcare workers (NHCW). NHCW were further categorized into residents of containment and non-containment zones and seroprevalence analyzed. Seroprevalence among different ABO blood groups was also analyzed. RESULTS: 1191 blood donors were tested for SARS-CoV-2 antibodies with 9.5 % seropositivity. Significantly lower seropositivity of 3.2 % (p < 0.001) was observed among HCW as compared to 10.9 % seropositivity in NHCW. Among NHCW no difference in seropositivity was observed based on residence in containment or non-containment zone. Significantly higher (p = 0.012) seroprevalence was observed among A blood group donors (12.5 %) as compared to O blood group donors (6.8 %). CONCLUSION: Results suggests that a blood donor, in a hospital setting is less likely to be exposed to COVID-19 disease than when participating in activities of daily living. It is postulated that the lower seroprevalence among HCW as compared to NHCW reflects differences in knowledge and practice of preventive measures among these groups. The findings should instil confidence among blood donors and motivate them to donate blood without fear.

A forecasting model to estimate the drop in blood supplies during the SARS-CoV-2 pandemic in Italy.

OBJECTIVES: To estimate the number of actually Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infected blood donors applying a statistical forecasting model. BACKGROUND: Following the outbreak of the SARS-CoV-2 epidemic, a drop in blood donation has been observed. It is crucial to determine the actual number of potential SARS-CoV-2-positive donors to define the measures and ensure adequate blood supply. METHODS: The cumulative incidence of SARS-CoV-2 positivity, calculated on the general population, was applied to the donor population by estimating the number of positive subjects. The calculation model was validated by the linear interpolation method. The number of blood units actually discarded based on post-donation information was also taken into account. RESULTS: Three months after the outbreak, 5322 donors were estimated to be positive for SARS-CoV-2 and were therefore potentially excluded from donation. A total of units of blood components were discarded following post donation information. The estimated number of donors deceased (180) and the number of clinically recovered individuals in the same period was also considered. CONCLUSION: This forecasting model can be used to obtain information on blood donors' involvement during future SARS-CoV-2 outbreaks, especially in case of changes concerning epidemiology, incidence by age bracket and geographical distribution and also for new outbreaks of emerging viruses.