No evidence of SARS-CoV-2 RNA among blood donors: A multicenter study in Hubei, China

The influence of the COVID-19 pandemic on blood donation and supply in China

INTRODUCTION

During the COVID-19 pandemic, there was a sharp decline in blood donation which posed a serious threat to the clinical blood supply worldwide. The aim of this study was to evaluate the influence of the COVID-19 pandemic on blood donation and supply in China on a nationwide level.

METHODS

A comprehensive review of the published literature was performed using eight databases including PubMed, Web of Science, Cochrane Library, Ovid, Embase, CNKI, WANFANG, and VIP by searching relevant words combinations.

RESULTS

Twenty-seven studies were determined to be eligible and included. Among them, 21 studies reported the situation of blood donation during the COVID-19 pandemic in China. The donation of both whole blood and platelet concentrates declined (with a decline of 5%-86% for whole blood and 3%-34% for platelet concentrates), with this especially evident in February 2020. The COVID-19 pandemic changed the pattern of blood donation and the composition of blood donors accordingly. Fifteen articles reported the supply of various blood components during the COVID-19 pandemic. The supply and usage of both packed red blood cell (PRBC) and fresh-frozen plasma (FFP) decreased (with a decrease of 4%-40% for PRBC and 9%-58% for FFP). The proportion of blood transfusions in different departments changed too. Compared to 2019, there was a decrease in surgical blood transfusions, and an increase in that used in treatments performed in emergency and internal medicine departments.

CONCLUSION

The COVID-19 pandemic has led to an overall reduction of blood transfusion activities in most cities in China, in particular blood donations and blood demands.

Risk of transfusion-transmitted infection with severe acute respiratory syndrome coronavirus 2 from blood donors in Japan

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) essentially affects respiratory organs and tissues. SARS-CoV-2 RNAemia is often associated with more severe cases of coronavirus disease 2019 (COVID-19) compared to cases without RNAemia. To determine the impact of the pandemic on transfusion medicine, particularly transfusion-related infection, we examined the frequency of blood donation with RNAemia, the viral RNA (vRNA) concentration, and any possibility of transfusion-transmitted infection (TTI) among transfusion recipients.

STUDY DESIGN AND METHODS

vRNA was examined in plasma/serum samples from 496 of 513 blood donors who reported having been infected with SARS-CoV-2 within 2 weeks of donation among a total of ca. 9.9 million blood donations in Japan between January 15, 2020, and December 31, 2021. The clinical course of patients transfused with the blood component containing vRNA was also examined.

RESULTS

vRNA was detected in 23 of 496 samples. The median period from blood donation to COVID-19 onset was 1 day in 16 RNAemia-positive donors. Most samples had vRNA concentrations below the limit of quantification. Three patients were transfused with either a packed red blood cell or platelet concentrate that tested positive for vRNA, showing no COVID-19 symptoms and testing negative for vRNA in post-transfusion blood.

CONCLUSION

The rate of RNAemia was 4.6% among blood donors who were found to be infected with SARS-CoV-2 shortly after donation, and vRNA concentrations in their donated blood were extremely low. There was no evidence of TTI in the recipients transfused with RNAemia-positive blood components. TTI risk in SARS-CoV-2 is negligible.

Re-examine the transfusion transmitted risk of SARS-CoV-2 virus during a major COVID-19 outbreak in 2022

INTRODUCTION

Although no case of COVID-19 transmission through transfusion has been reported, blood transfusion service (BTS) continues to implement pre-donation and post-donation measures to minimise the risk. In year 2022, when local healthcare system was badly impacted by a major outbreak, it opened an opportunity to re-examine the viraemia risk in these asymptomatic donors.

MATERIALS AND METHODS

Records were retrieved from blood donors who reported COVID-19 after donation and follow-up was also made for recipients who received their blood. Blood samples at donation were tested for SARS-CoV-2 viraemia by single-tube nested real-time RT-PCR assay designed to detect most SARS-CoV-2 variants including the prevailing delta and omicron variants.

RESULTS

From 1 January to 15 August 2022, the city with 7.4 M inhabitants recorded 1 187 844 COVID-19 positive cases and 125 936 successful blood donations were received. 781 donors reported to the BTS after donation with 701 being COVID-19 related (including close contact and symptoms respiratory tract infection). 525 COVID-19 were positive at the time of call back or follow-up. Of the 701 donations, they were processed into 1480 components with 1073 discarded upon donors' call back. For remaining 407 components, no recipient was found to have adverse event or COVID-19 positive. 510 samples from the above 525 COVID-19 positive donors were available and all tested negative for SARS-CoV-2 RNA.

DISCUSSION

With the negative SARS-CoV-2 RNA in blood donation samples and follow up data in transfusion recipients, the risk of transfusion transmitted COVID-19 appears negligible. However, current measures remains important in securing blood safety with ongoing surveillance of their effectiveness.

SARS-CoV-2 and post-donation information: a one-year experience of the French haemovigilance network

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.

Views and Attitudes of Blood Donors toward Blood Donation during the COVID-19 Pandemic in Thrace Region, Greece

The COVID-19 pandemic has been going on for the last two years and it has affected our society and, amongst other things, has had a negative impact on blood donation, which has led to a significant reduction in blood supplies worldwide. The imposed restrictions in terms of physical presence and transportation, and the fear of the unknown, have aggravated the situation. In Greece, after the first cases of COVID-19 were reported, the blood supplies at the blood transfusion units (BTUs) were dramatically reduced. Although the blood transfusions were lessened during the COVID-19 pandemic period, the blood stocks at all the BTUs of the country were also reduced.

Plasma procurement and plasma product safety in light of the COVID-19 pandemic from the perspective of the plasma industry

This review, written from the perspective of the plasma industry, discusses plasma procurement and plasma product safety in light of the COVID‐19 pandemic. The COVID‐19 pandemic impacted the whole world and, therefore, not unexpectedly, the pharmaceutical industry too. In spite of this, the plasma protein industry has continued to provide life saving therapies to critically ill patients. Moreover, companies have collected COVID convalescent plasma (CP) to support development of investigational therapies, for example, hyperimmune globulins to potentially treat SARS‐CoV‐2 infection, and collaborated with those collecting COVID CP for direct transfusion, which has been made available under emergency use in the United States. For plasma that is fractionated to become a therapy, general knowledge of coronaviruses and numerous new studies on the structure and function of SARS‐CoV‐2 provide reassurance that existing industry precautions, including donor selection, as well as virus inactivation and removal steps during the manufacturing process are sufficient to maintain the high standards of virus safety of plasma products. The pandemic also revealed the vulnerability and inadequacy of the current plasma ecosystem. There is a need for more plasma to be collected around the world to meet the growing need for safe and efficacious plasma‐derived therapies. This requires outdated regulatory and policy restrictions to be realigned with current scientific evidence. More countries around the world should be in a position to contribute to global supply of plasma so that patients with life‐threatening conditions ‐ and often no alternative therapeutic solutions ‐ have better access to care.

Low rate of RNAemia in blood donations collected during the first wave of COVID-19 in France

BACKGROUND

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.

METHODS

Archived plasma samples randomly selected from donations collected between 23 and 29 March, 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 4 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.

RESULTS

Among the 2,818 MP4 (corresponding to 9,672 donations) tested for viral RNA, 5 were weakly reactive. Among the 20 plasmas included in these 5 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 non-reactive 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.

CONCLUSION

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. This article is protected by copyright. All rights reserved.

Modelling RT-qPCR cycle-threshold using digital PCR data for implementing SARS-CoV-2 viral load studies

OBJECTIVES

To exploit the features of digital PCR for implementing SARS-CoV-2 observational studies by reliably including the viral load factor expressed as copies/μL.

METHODS

A small cohort of 51 Covid-19 positive samples was assessed by both RT-qPCR and digital PCR assays. A linear regression model was built using a training subset, and its accuracy was assessed in the remaining evaluation subset. The model was then used to convert the stored cycle threshold values of a large dataset of 6208 diagnostic samples into copies/μL of SARS-CoV-2. The calculated viral load was used for a single cohort retrospective study. Finally, the cohort was randomly divided into a training set (n = 3095) and an evaluation set (n = 3113) to establish a logistic regression model for predicting case-fatality and to assess its accuracy.

RESULTS

The model for converting the Ct values into copies/μL was suitably accurate. The calculated viral load over time in the cohort of Covid-19 positive samples showed very low viral loads during the summer inter-epidemic waves in Italy. The calculated viral load along with gender and age allowed building a predictive model of case-fatality probability which showed high specificity (99.0%) and low sensitivity (21.7%) at the optimal threshold which varied by modifying the threshold (i.e. 75% sensitivity and 83.7% specificity). Alternative models including categorised cVL or raw cycle thresholds obtained by the same diagnostic method also gave the same performance.

CONCLUSION

The modelling of the cycle threshold values using digital PCR had the potential of fostering studies addressing issues regarding Sars-CoV-2; furthermore, it may allow setting up predictive tools capable of early identifying those patients at high risk of case-fatality already at diagnosis, irrespective of the diagnostic RT-qPCR platform in use. Depending upon the epidemiological situation, public health authority policies/aims, the resources available and the thresholds used, adequate sensitivity could be achieved with acceptable low specificity.

The Impact of COVID-19 on Blood Transfusion Services: A Systematic Review and Meta-Analysis

Introduction

While SARS-CoV-2's main transmission route is through respiratory droplets, research has found that viral RNA could be detected in blood samples, causing concerns over the safety of blood donations and blood products. This paper therefore aims to systematically search for studies that have addressed their country's lack of donations and analyse the risk of blood transfusion-transmission. As such, it will answer the question "should blood services focus more on donation vigilance or worry more about the risks of transmission through blood products?"

Methods

38 articles were identified through a systematic review adopting the PRISMA and STROBE guidelines. Meta-analysis was conducted using OpenMeta software.

Results

The average decrease in blood donations was found to be 38%, with some regions showing up to 67% decrease. To assess the risk of actual blood transfusion-transmission, three datasets were analysed. Firstly, the viral load in COVID-19 patients was studied and found to have less than 1% detection rate (ARD = -0.831, 95% -0.963, -0.699). Secondly, the prevalence of finding viral RNA in a pool of donations was nearly -1.503 (ARD = -1.538, -1.468). Lastly, recipients who were given blood products of positive donors were found to be -0.911 (ARD 95% = -1.247, -0.575).

Discussion/Conclusion

Blood centres should focus more on launching initiatives and policies that would increase their countries' blood supply as the virus has no direct threat to blood safety.

The Impact of COVID-19 Pandemic on Blood Transfusion Services: A Perspective from Health Professionals and Donors

Purpose

Since the emergence of the COVI9-19 pandemic, there has been concern about the availability and sufficiency of blood transfusions to meet patient needs. Also, the adequate and safe blood supply is a major issue to fulfill present demands. This study aims to determine the impact of the COVID-19 pandemic on the blood transfusion service and identify solutions to overcome this impact from the perspective of blood donors and healthcare professionals.

Methods

This study was conducted prospectively among Saudi Arabian blood donors and healthcare professionals between May 2020 and May 2021. A group of professional health care professionals and blood donors participated in this study to determine the impact of the COVID-19 pandemic on blood transfusion services and identify possible solutions to overcome the adverse effects on blood system activities.

Results

To understand the impact of pandemic COVID-19 on blood transfusion services in Saudi Arabia, we investigated population dynamics and statistical analysis from different age groups and health care professionals. A total of 424 blood donors and 372 healthcare professionals participated in this study. The suggested solution by the participants to overcome the blood shortage during pandemics was the organization of mobile blood drives at donors’ homes, work, and educational sites. Statically significant associations were found between blood donation during this pandemic and age (p=0.019) and marital status (p=0.001).

Conclusion

The findings of this study highlight the main problems of blood transfusion due to the onset of COVID-19. Hence, the data could be a source of improving blood transfusion and blood donation systems by healthcare centers and on an individual basis. Healthcare professionals use this public management system in hospitals to minimize the adverse effects of the pandemic.

Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use:

https://youtu.be/K89bLDL2t3A

Impact of COVID-19 and lockdown regarding blood transfusion

BACKGROUND

The outbreak of a SARS-CoV-2 resulted in a massive afflux of patients in hospital and intensive care units with many challenges. Blood transfusion was one of them regarding both blood banks (safety, collection, and stocks) and consumption (usual care and unknown specific demand of COVID-19 patients). The risk of mismatch was sufficient to plan blood transfusion restrictions if stocks became limited.

STUDY DESIGN AND METHODS

Analyses of blood transfusion in a tertiary hospital and blood collection in the referring blood bank between February 24 and May 31, 2020.

RESULTS

Withdrawal of elective surgery and non-urgent care and admission of 2291 COVID-19 patients reduced global activity by 33% but transfusion by 17% only. Only 237 (10.3) % of COVID-19 patients required blood transfusion, including 45 (2.0%) with acute bleeding. Lockdown and cancellation of mobile collection resulted in an 11% reduction in blood donation compared to 2019. The ratio of reduction in blood transfusion to blood donation remained positive and stocks were slightly enhanced.

DISCUSSION

Reduction of admissions due to SARS-CoV-2 pandemic results only in a moderate decrease of blood transfusion. Incompressible blood transfusions concern urgent surgery, acute bleeding (including some patients with COVID-19, especially under high anticoagulation), or are supportive for chemotherapy-induced aplasia or chronic anemia. Lockdown results in a decrease of blood donation by cancellation of mobile donation but with little impact on a short period by mobilization of usual donors. No mismatch between demand and donation was evidenced and no planned restriction to blood transfusion was necessary.

Analysis of current SARS-CoV-2 infection in a large population of blood donors evidenced that RNAemia is rare in plasma

BACKGROUND

Transmission of SARS-CoV-2 by asymptomatic individuals and by blood transfusion are important issues to understand to control the viral spread. In this work, we estimated the current SARS-CoV-2 infection rate in blood donors from Belo Horizonte, Brazil.

STUDY DESIGN AND METHODS

Saliva and blood samples were collected from 4103 blood donors from June 15 to September 30, 2020. Saliva samples were tested by real-time RT-PCR for SARS-CoV-2 in mini-pools of four samples. Individual samples were tested for positive or inconclusive pools, and positive donors had their plasma tested.

RESULTS

Twenty-seven (0.66%) blood donors were positive for SARS-CoV-2 in their saliva, but their plasma was negative, except for one, who presented a high viral load in saliva and nasopharyngeal samples and RNAemia in the plasma close to the limit of detection. Fourteen (56%) positive blood donors reported mild symptoms related to COVID-19 after donation, but the viral load levels were not statistically different between symptomatic and asymptomatic individuals.

DISCUSSION

Despite the measures taken by Blood Centers to avoid blood donors with SARS-CoV-2 infection, asymptomatic or presymptomatic carriers are able to donate. The risk of the virus transmission by transfusion seems to be negligible since plasma RNAemia was seen at a very low level in only one (3.7%) of the positive donors, but other studies must be performed to confirm this finding.

Minipool testing for SARS-CoV-2 RNA in United States blood donors

BACKGROUND

SARS-CoV-2 RNA prevalence in blood donors from large geographic areas of high community transmission is limited. We tested residual donor plasma minipools (MPs) to determine SARS-CoV-2 RNAemia prevalence in six United States areas.

STUDY DESIGN/METHODS

Blood donations collected from 7 March 2020 to 25 September 2020 were tested for SARS-CoV-2 RNA (vRNA) in MP of 6 or 16 donations using the Grifols Procleix SARS-CoV-2 research-use only (RUO) transcription-mediated amplification (TMA) assay. Reactive results were confirmed using an alternate target region TMA assay. Reactive MPs were tested by TMA after serial dilution to estimate viral load. Testing for anti-SARS-CoV-2 antibodies and infectivity was performed.

RESULTS

A total of 17,995 MPs corresponding to approximately 258,000 donations were tested for vRNA. Three confirmed reactive MP16 were identified. The estimated prevalence of vRNA reactive donations was 1.16/100,000 (95% CI 0.40, 3.42). The vRNA-reactive samples were non-reactive for antibody, and the estimated viral loads of the (presumed single) positive donations within each MP ranged from <1000 to <4000 copies/ml. When tested, no infectivity was observed in inoculated permissive cell cultures.

DISCUSSION

Blood donation MP-nucleic acid testing (NAT) indicated that SARS-CoV-2 RNAemia is infrequent and, when detected, the vRNA was at low concentrations. Only one RNA-reactive MP could be tested for infectivity for operational reasons and was not infectious in cell culture. These findings support current recommendations from international and national regulatory agencies to not screen donors by NAT.

Sensitive tracking of circulating viral RNA through all stages of SARS-CoV-2 infection

BACKGROUNDCirculating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA may represent a more reliable indicator of infection than nasal RNA, but quantitative reverse transcription PCR (RT-qPCR) lacks diagnostic sensitivity for blood samples.METHODSA CRISPR-augmented RT-PCR assay that sensitively detects SARS-CoV-2 RNA was employed to analyze viral RNA kinetics in longitudinal plasma samples from nonhuman primates (NHPs) after virus exposure; to evaluate the utility of blood SARS-CoV-2 RNA detection for coronavirus disease 2019 (COVID-19) diagnosis in adults cases confirmed by nasal/nasopharyngeal swab RT-PCR results; and to identify suspected COVID-19 cases in pediatric and at-risk adult populations with negative nasal swab RT-qPCR results. All blood samples were analyzed by RT-qPCR to allow direct comparisons.RESULTSCRISPR-augmented RT-PCR consistently detected SARS-CoV-2 RNA in the plasma of experimentally infected NHPs from 1 to 28 days after infection, and these increases preceded and correlated with rectal swab viral RNA increases. In a patient cohort (n = 159), this blood-based assay demonstrated 91.2% diagnostic sensitivity and 99.2% diagnostic specificity versus a comparator RT-qPCR nasal/nasopharyngeal test, whereas RT-qPCR exhibited 44.1% diagnostic sensitivity and 100% specificity for the same blood samples. This CRISPR-augmented RT-PCR assay also accurately identified patients with COVID-19 using one or more negative nasal swab RT-qPCR results.CONCLUSIONResults of this study indicate that sensitive detection of SARS-CoV-2 RNA in blood by CRISPR-augmented RT-PCR permits accurate COVID-19 diagnosis, and can detect COVID-19 cases with transient or negative nasal swab RT-qPCR results, suggesting that this approach could improve COVID-19 diagnosis and the evaluation of SARS-CoV-2 infection clearance, and predict the severity of infection.TRIAL REGISTRATIONClinicalTrials.gov. NCT04358211.FUNDINGDepartment of Defense, National Institute of Allergy and Infectious Diseases, National Institute of Child Health and Human Development, and the National Center for Research Resources.

Comparison of Digital PCR and Quantitative PCR with Various SARS-CoV-2 Primer-Probe Sets

The World Health Organization (WHO) has declared the coronavirus disease 2019 (COVID-19) as an international health emergency. Current diagnostic tests are based on the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method, which is the gold standard test that involves the amplification of viral RNA. However, the RT-qPCR assay has limitations in terms of sensitivity and quantification. In this study, we tested both qPCR and droplet digital PCR (ddPCR) to detect low amounts of viral RNA. The cycle threshold (C_T) of the viral RNA by RT-PCR significantly varied according to the sequences of the primer and probe sets with in vitro transcript (IVT) RNA or viral RNA as templates, whereas the copy number of the viral RNA by ddPCR was effectively quantified with IVT RNA, cultured viral RNA, and RNA from clinical samples. Furthermore, the clinical samples were assayed via both methods, and the sensitivity of the ddPCR was determined to be equal to or more than that of the RT-qPCR. However, the ddPCR assay is more suitable for determining the copy number of reference materials. These findings suggest that the qPCR assay with the ddPCR defined reference materials could be used as a highly sensitive and compatible diagnostic method for viral RNA detection.

Performance of a Point of Care Test for Detecting IgM and IgG Antibodies Against SARS-CoV-2 and Seroprevalence in Blood Donors and Health Care Workers in Panama

Novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic, which has reached 28 million cases worldwide in 1 year. The serological detection of antibodies against the virus will play a pivotal role in complementing molecular tests to improve diagnostic accuracy, contact tracing, vaccine efficacy testing, and seroprevalence surveillance. Here, we aimed first to evaluate a lateral flow assay's ability to identify specific IgM and IgG antibodies against SARS-CoV-2 and second, to report the seroprevalence estimates of these antibodies among health care workers and healthy volunteer blood donors in Panama. We recruited study participants between April 30th and July 7th, 2020. For the test validation and performance evaluation, we analyzed serum samples from participants with clinical symptoms and confirmed positive RT-PCR for SARS-CoV-2, and a set of pre-pandemic serum samples. We used two by two table analysis to determine the test positive and negative percentage agreement as well as the Kappa agreement value with a 95% confidence interval. Then, we used the lateral flow assay to determine seroprevalence among serum samples from COVID-19 patients, potentially exposed health care workers, and healthy volunteer donors. Our results show this assay reached a positive percent agreement of 97.2% (95% CI 84.2-100.0%) for detecting both IgM and IgG. The assay showed a Kappa of 0.898 (95%CI 0.811-0.985) and 0.918 (95% CI 0.839-0.997) for IgM and IgG, respectively. The evaluation of serum samples from hospitalized COVID-19 patients indicates a correlation between test sensitivity and the number of days since symptom onset; the highest positive percent agreement [87% (95% CI 67.0-96.3%)] was observed at ≥15 days post-symptom onset (PSO). We found an overall antibody seroprevalence of 11.6% (95% CI 8.5-15.8%) among both health care workers and healthy blood donors. Our findings suggest this lateral flow assay could contribute significantly to implementing seroprevalence testing in locations with active community transmission of SARS-CoV-2.

Comparison of Seven Commercial Severe Acute Respiratory Syndrome Coronavirus 2 Nucleic Acid Detection Reagents with Pseudovirus as Quality Control Material

The ongoing pandemic of coronavirus disease 2019 threatens the whole world, which catalyzes a variety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid test (NAT) kits. To monitor test quality and evaluate NAT kits, quality control materials that best simulate real clinical samples are needed. In this study, the performance of SARS-CoV-2 cell culture supernatant, PCDH-based pseudovirus, and MS2-based pseudovirus as quality control materials was compared. PCDH-based pseudovirus was found to be more similar in characteristics to SARS-CoV-2 particle, and more suitable for evaluating SARS-CoV-2 NAT kits than MS2-based pseudovirus. Proper detection using sensitive and precise NAT kits is essential to guarantee diagnosis. Thus, limit of detection, precision, anti-inference ability, and cross-reactivity of NAT kits from PerkinElmer, Beijing Wantai Biological Pharmacy Enterprise Co, Ltd, Shanghai Kehua Bio-Engineering Co, Ltd, Sansure Biotech Inc., Da An Gene Co, Ltd, Shanghai BioGerm Medical Biotechnology Co, Ltd, and Applied Biological Technologies Co, Ltd, were compared using PCDH-based pseudovirus. For the seven kits evaluated, N gene was more sensitive than ORF1ab gene in most kits, whereas E gene was most sensitive among the three genes in Shanghai Kehua Bio-Engineering Co, Ltd, and Applied Biological Technologies Co, Ltd. PerkinElmer got the lowest limit of detection for N gene at 11.61 copies/mL, and the value was 34.66 copies/mL for ORF1ab gene. All of the kits showed good precision, with CV values less than 5%, as well as acceptable anti-interference ability of 2 mg/L human genomic DNA. No cross-reactivity was observed with other respiratory viruses.

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.

The prevalence of past SARS‐CoV‐2 infection was relatively low among voluntary blood donors in Guangzhou, China

Screening of SARS‐CoV‐2 among voluntary blood donors may not be in priority in Guangzhou, China, because of the low risk of transmission via transfusion.

No evidence of SARS-CoV-2 RNA among blood donors: A multicenter study in Hubei, China

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA could be detected in the blood of infected cases. From February 9, all blood establishments in Hubei province, China, implemented nucleic acid testing (NAT) for SARS-CoV-2 RNA among blood donors to ensure blood safety.

STUDY DESIGN AND METHODS

Nucleic acid test screening individually (ID) or by minipool (MP) testing was performed according to the manufacturer's instructions. Inactivated culture supernatant of SARS-CoV-2-infected Vero cells was quantified by droplet digital polymerase chain reaction (ddPCR) and series diluted with negative plasma to evaluate the assay's performance.

RESULTS

The limit of detection of the kit for MP testing was 62.94 and 33.14 copies/mL for N and ORF1ab region, respectively. ID testing could achieve 3.87 and 4.85 copies/mL for two regions using 1600 μL of plasma. Coefficients of variations of two different concentrations of reference samples were all less than 5% in MP testing. As of April 30, 2020, a total of 98,342 blood donations including 87,095 whole blood donations and 11,247 platelet donations were tested by ID or MP testing, and no RNAemia was found. In addition, Hubei province suffered precipitously decreased blood supply, especially in February: 86% reduction compared with the same period of 2019.

CONCLUSION

Nucleic acid test screening of SARS-CoV-2 on blood donations is suitable in blood establishments using the commercial real-time PCR detection kit based on available instruments. The negative result indicated that SARS-CoV-2 appears to be no direct threat to blood safety but raises some serious issues for general blood supply.