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

Abstract

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.

Figure 1

Screening and confirmation algorithm Name of assays are indicated, as well as number of replicates, if appropriate. Positive samples with the screening test (R-GENE PCR1) were submitted to 2 secondary real-time (RT)-PCR assays, leading to repeat-reactive and inconclusive samples. All samples were subjected to Sanger sequencing using 2 RT-PCRs, using primers designed by the ARTIC network, targeting the spike and nucleocapsid gene, and additional primers to detect variants in repeat-reactive samples. Positive and inconclusive samples for which the plasma bag was available were also subjected to next generation sequencing using COVIDSeq Test (Illumina, San Diego, CA, USA). Samples were classified as “confirmed” when a sequence, at least partial, was obtained,” repeat-reactive” when another RT molecular test was positive, and “suspected” if the screening assay was positive without any further positive assay.

Figure 2

Evolution of the weekly number of donations, the number of COVID-19-related post-donation information (PDI) donations, and the number of samples analysed and testing positive during the study period

Figure 3

Population demographic and geographic data a. Age of blood donors (BD) reporting confirmed COVID-19 (COVID+), possible-COVID, or contact-case post-donation information (PDI). b. Distribution of age in the COVID-19-related PDI blood donor and all blood donor populations expressed as the ratio PDI BD/total BD. c. Geographic distribution of PDI blood donors (ratio to the total BD population per region) and RNAemic blood donors during the study period (ratio to the PDI donors per region).

Figure 4

Lapsed time between donation and (a) symptoms (Δ1); (b) a positive test in the upper respiratory samples (Δ2); and (c) post-donation information (PDI) (Δ3), and (d) between a positive nasopharyngeal (NP) real-time (RT)-PCR or the onset of symtoms and PDI (Δ4) Median and 95% Confidence Interval (95% CI) of median are indicated by the black and gray horizontal bars, respectively.