Asymptomatic Donors Research Articles

Safety of Hepatitis B Virus Screening in Blood Donors from the Hospital Foundation of Hematology and Hemotherapy of the State of Amazonas (HEMOAM) in the Brazilian Amazon

Background: Hepatitis B is an infectious disease of worldwide importance and of great interest to transfusion medicine. The Amazon region has areas of high endemicity, outlining a worrying scenario for transfusion and epidemiological safety. Objective: To analyze the profiles of serological and molecular markers for HBV of blood donors from HEMOAM. Methods: Blood donors with different patterns of reactivity in serological and molecular screening for HBV were tested for viral load by the qPCR method at the reference center for liver diseases in the state of Amazonas. Results: A total of 230,591 donors were tested, with 3104 (1.34%) found reactive for HBV and 2790 (89.9%) found reactive for isolated anti-HBc. Viral load was not detected in 100% of donors reactive only to HBsAg, while 100% of donors with positive anti-HBc and positive HBsAg or HBV NAT demonstrated a detectable viral load. We also detected one case of occult hepatitis B (0.03%) only with reactive HBV NAT and five donors (0.2%) with positive anti-HBc and HBV NAT. Conclusions: With this result, the great importance of the anti-HBc test for the unsuitability of blood donors was verified, as well as the fundamental introduction of the HBV NAT test in screening for hepatitis B in Brazilian blood banks, as this was the only way to detect the viral infection burden in asymptomatic donors who previously would not be treated, which contributed to the maintenance of the endemicity of hepatitis B in the Brazilian Amazon.

Urban arbovirus exposure in blood donations from an endemic area of Brazil.

In Brazil, urban arboviruses, such as dengue virus (DENV), Zika virus (ZIKV) and chikungunya virus (CHIKV), constitute a major public health problem, and due to their endemicity and asymptomatic cases, they pose a potential threat to blood donations. Rio de Janeiro (RJ), Brazil, has been impacted by extensive DENV epidemics over the last 30 years and, after 2015, by CHIKV and ZIKV. Urban arboviruses DENV, ZIKV and CHIKV were investigated in blood donations (n = 778) at the State Institute of Hematology, HEMORIO (RJ) from 2019 to 2022 by serological and molecular methods. An overall arbovirus exposure was observed in 26.1% of the blood donations. Anti-DENV IgM was detected in 4.0% of samples and two donations were DENV NS1 positive. Positive anti-CHIKV IgM was observed in 4.7% of the donations. Co-detection of anti-CHIKV IgMand anti-DENV IgM was observed in 1.0% of donors, and CHIKV prevalence was 21.3%. All blood donations tested were negative for the DENV, ZIKV and CHIKV RNA. IgM seroprevalence to the arboviruses analyzed here is an indicator of recent infection in asymptomatic donors, showing that the population of blood donors can be a vehicle for new infections, especially during epidemic periods.

Transplantation in the Pandemic Era: Perspectives on the Utilization of COVID-19 Positive Organs

At early stages of the pandemic, most organ procurements organizations considered COVID-19 infected donors to be ineligible for organ donation. The aim of this survey is to describe the current practices of the utilization of COVID-19 positive organs donors among American Society of Transplant Surgeons (ASTS) members. An anonymous 40-question redcap survey was emailed to ASTS members from June to August 2022. One hundred forty-nine surveys from 10 countries were included for analysis. The majority of the responders were men (66.7%) from North America (95%) and identified as transplant surgeons (68.5%). Most work at academic institutions (76.5%). Almost all responders (94%) were willing to accept an organ from a donor with a history of COVID-19 who tested negative at the time of donation, however, there was no consensus on the length of time after the disease was resolved. Approximately 70% indicated they accept organs from asymptomatic donors with active disease. Only 32 responders indicated they would accept an organ from an individual with a history of "severe" COVID-19 infection and less than one third of the responders would accept an organ from a donor who died from COVID-19 infection. Interestingly, 80% indicated they have protocols at their institution to guide the acceptance of such organs. Despite new evidence that the transmission of COVID-19 in non-lung organs is extremely rare, the results of this survey suggest significant heterogeneity in practice and perceptions of the use of COVID-19 positive organs across international centers. We suggest that the implementation of a standardized protocol is of paramount importance to continue safe transplant activity.

Evolución de la seroprevalencia de COVID-19 en bancos de sangre durante la pandemia en la región Lima, Perú

Introduction. Peru was one of the countries most affected by the COVID-19 pandemic, with more than 220,000 deaths recorded due to SARS-CoV-2 infection. Given the constant mutations of the virus and registered variants, it is important to carry out research that reflects the evolution of the humoral immune state. Objective. Measure the seroprevalence of COVID-19 during the pandemic in the department of Lima in the period between April 1, 2020 and June 30, 2022, in donor samples from 6 hospital blood banks public of Lima, Peru. Methods. A descriptive, transversal, observational and retrospective study was carried out evaluating the presence of IgM/IgG antibodies against SARS-CoV-2 using lateral flow chromatographic immunoassay in samples from healthy and asymptomatic donors from blood banks of 6 health facilities in the department of Lima. Results. A progressive increase in the seroprevalence of IgG and total reactivity of IgM/ IgG antibodies against SARS-CoV-2 will be observed as follows: 22,6% - 32,7% during 2020; 53,9% - 58,1% during 2021; 88,9% - 93,3% during the first half of 2022. Conclusions. The reactivity and presence of anti- SARS-CoV-2 antibodies progressively increase during the COVID-19 pandemic from 11,2% to 98,4% in the samples evaluated, possibly with the impact of the pandemic waves and the active vaccination campaign against COVID-19.

West Nile virus surveillance using sentinel birds: results of eleven years of testing in corvids in a region of northern Italy.

The natural transmission cycle of West Nile virus (WNV) involves birds as primary hosts and mosquitoes as vectors, but this virus can spread to mammals, human beings included. Asymptomatic infected donors pose a risk to the safety of blood transfusions and organ transplants, as WNV can be transmitted through these medical procedures. Since 2009, the region of Emilia-Romagna in northern Italy has been implementing an integrated surveillance system in order to detect WNV circulation in the environment at an early stage. Here we report the results of the two components of the surveillance system, the active testing of corvids and humans, and demonstrate that bird surveillance alone improves a surveillance system based solely on human case detection. As WNV risk reduction measures are applied on a provincial basis, we assessed the ability of this surveillance system component to detect virus circulation prior to the notification of the first human case for each province. Overall, 99 epidemic seasons were evaluated as a result of 11 years (2013-2023) of surveillance in the nine provinces of the region. In this period, 22,314 corvids were tested for WNV and 642 (2.9%) were found to be infected. WNV was generally first detected in birds in July, with sample prevalence peaks occurring between August and September. During the same period, 469 autochthonous human cases were notified, about 60% of which were reported in August. WNV was detected 79 times out of the 99 seasons considered. The virus was notified in birds 73 times (92.4%) and 60 times (75.9%) in humans. WNV was first or only notified in birds in 57 seasons (72.1%), while it was first or only notified in humans in 22 seasons (27.8%). Active surveillance in corvids generally allows the detection of WNV before the onset of human cases. Failure of virus detection occurred mainly in seasons where the number of birds tested was low. Our results show that active testing of a minimum of 3.8 corvids per 100 km2 provides a satisfactory timeliness in the virus detection, but for early detection of WNV it is crucial to test birds between mid-June and mid-August.

High prevalence of dengue, Zika, and chikungunya viruses in blood donors during a dengue outbreak and an endemic period in Colombia.

Arboviruses pose a challenge in ensuring the supply of pathogen-free blood components because they are not routinely screened in blood banks, and blood components from infected asymptomatic donors could be transfused. This study aimed to detect and characterize arboviral infections in Colombian blood donors. In a cross-sectional study, the prevalence of dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses and co-infections of blood donors were compared between an epidemic period (November 2019-February 2020, n = 462) and an endemic period (November 2021-August 2022, n = 1,119). Viral RNA from each donor serum was purified, and the viruses were detected using a previously standardized multiplex hemi-nested RT-PCR protocol. Subsequently, donors who tested positive were surveyed 15 days after the detection of the virus to identify clinical characteristics related to the arboviral infection. The prevalences of each virus were presented as percentages and compared between epidemic and endemic periods. Significantly higher prevalences were found in the epidemic period compared with the endemic period for DENV (14.5 vs. 1.9%), ZIKV (7.8 vs. 0.3%), CHIKV (8 vs. 3.3%), and co-infections (4.3 vs. 0.2%). The survey response rate of positive donors in the two periods was 83/175 (47%). In total, 57% of the donors surveyed were asymptomatic. Symptomatic donors most frequently reported headache (31%), malaise (13%), arthralgia (10%), and fever/chills (8%). The prevalence observed in epidemic and endemic periods was higher than that reported in other studies in the Americas. The high proportion of asymptomatic cases found, in addition to the mild and nonspecific manifestations among the symptomatic, may limit the effectiveness of the donor selection criteria used to mitigate the risk of transfusion-transmitted arboviruses.

Stimulation of PSTPIP1 to trigger proinflammatory responses in asymptomatic SARS-CoV-2 infections

BackgroundA hyperinflammatory response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection gravely worsens the clinical progression of coronavirus disease 2019 (COVID-19). Although the undesirable effects of inflammasome activation have been correlated to the severity of COVID-19, the mechanisms of this process in the asymptomatic infection and disease progression have not yet been clearly elucidated. MethodsWe performed strand-specific RNA sequencing in 39 peripheral blood mononuclear cell (PBMC) samples from asymptomatic individuals（n = 10）, symptomatic patients（n = 16） and healthy donors（n = 13）. ResultsDysregulation of pyrin inflammasomes along with the proline-serine-threonine phosphatase-interacting protein 1 (PSTPIP1) gene was identified in SARS-COV-2 infection. Notably, the PSTPIP1 expression level showed a significant negative correlation with an adjacent long-noncoding RNA (lncRNA) RP11-797A18.6 in the asymptomatic individuals compared with the healthy controls. In addition, a decline in the nuclear factor kappa B subunit 1 (NFKB1) gene expression was observed in asymptomatic infection, followed by a rise in the mild and moderate disease stages, suggesting that altered NFKB1 expression and associated proinflammatory signals may trigger a disease progression. ConclusionsOverall, our results indicate that PSTPIP1-dependent pyrin inflammasomes-mediated pyroptosis and NF-κB activation might be potential preventive targets for COVID-19 disease development and progression.

Detection of Plasmodium spp. in asymptomatic blood donors by the new Brazilian NAT PLUS HIV/HBV/HCV/Malaria Bio-Manguinhos kit.

Transfusion-transmitted malaria (TTM) is a public health problem in endemic and nonendemic areas. The Brazilian Ministry of Health (MH) requested the development of a nucleic acid amplification test (NAT) for the detection of Plasmodium spp. in public blood centers to increase blood safety. The new Brazilian NAT kit named NAT PLUS HIV/HBV/HCV/Malaria Bio-Manguinhos was first implemented in HEMORIO, a public blood center in the city of Rio de Janeiro. Since October 1, 2022, this blood center has been testing all its blood donations for malaria in a pool of six plasma samples to detect Plasmodium spp. by real-time polymerase chain reaction (PCR). Since the implementation of the NAT PLUS platform until February 2023, HEMORIO has successfully received and tested 200,277 donations. The platform detected two asymptomatic donors in the city of Rio de Janeiro, which is a nonendemic region for malaria. Our analyses suggested a malaria from the Amazon region caused by Plasmodium vivax, in the first case, while an autochthonous transmission case by Plasmodium malariae was identified in the rural area of Rio de Janeiro state. The NAT PLUS platform detects Plasmodium spp. in plasma samples with sensitivity capable of detecting subpatent infections. This is the first time worldwide that a group developed and implemented molecular diagnosis for Plasmodium spp. to be used by public blood centers to avoid TTM.

A novel mitigation strategy for the prevention of transfusion-transmitted malaria.

Malaria is caused by protozoa of the genus Plasmodium and transmitted by Anopheles mosquitos. In the US, blood donors are assessed for malaria risk, including donor travel or previous residence in endemic areas and history of malaria by questionnaire and deferred for three months or three years, respectively. The Procleix Plasmodium Assay is a qualitative nucleic acid test based on transcription-mediated amplification (TMA) for the detection of 18S ribosomal RNA of P. falciparum, P. ovale, P. vivax, P. malariae, and P. knowlesi for use on the Procleix Panther system. Analytical sensitivity was evaluated with in vitro transcripts and infected red blood cells. For clinical specificity, 12,800 individual donations and 283 pools of 16 samples from routine US donors were screened. Malaria risk was evaluated by testing 862 donors deferred for 3 years. Reactive results were confirmed with in-house real-time TMA assay and serology. Assay sensitivity was 8.47-11.89 RNA copies/mL and 2.10-6.82 infected red cells/mL. Specificity was 99.99% in 12,800 individual donations and 100% in 283 pools of 16. Of 862 tested deferred donor samples, one donor (0.12%) confirmed positive individually and in pools; he remained confirmed positive for 13 months. The infected donor was a prior resident of a malaria-endemic area in West Africa. The Procleix Plasmodium Assay showed high sensitivity and specificity and detected Plasmodium RNA in an asymptomatic presenting donor. This assay may prove helpful as a screening test versus the use of risk questions to reduce the number of donors deferred for malaria risk.

Early cellular and molecular signatures correlate with severity of West Nile virus infection

Infection with West Nile virus (WNV) drives a wide range of responses, from asymptomatic to flu-like symptoms/fever or severe cases of encephalitis and death. To identify cellular and molecular signatures distinguishing WNV severity, we employed systems profiling of peripheral blood from asymptomatic and severely ill individuals infected with WNV. We interrogated immune responses longitudinally from acute infection through convalescence employing single-cell protein and transcriptional profiling complemented with matched serum proteomics and metabolomics as well as multi-omics analysis. At the acute time point, we detected both elevation of pro-inflammatory markers in innate immune cell types and reduction of regulatory Tcell activity in participants with severe infection, whereas asymptomatic donors had higher expression of genes associated with anti-inflammatory CD16+ monocytes. Therefore, we demonstrated the potential of systems immunology using multiple cell-type and cell-state-specific analyses to identify correlates of infection severity and host cellular activity contributing to an effective anti-viral response.

P‐BT‐12 | Forensic Sequencing of Salmonella Cultured from HPC(A) Products from Two Asymptomatic Donors

P‐BT‐12 | Forensic Sequencing of Salmonella Cultured from HPC(A) Products from Two Asymptomatic Donors

Study of SARS-CoV-2 in semen from asymptomatic donors with the presence of virus in nasopharyngeal swabs

Is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) present in semen samples from asymptomatic donors who have positive virus results from nasopharyngeal swabs? Nasopharyngeal PCR was performed on 1943 sperm donors between January 2021 and March 2022. The result was positive for 140 donations, and the presence of SARS-CoV-2 could be studied in cryopreserved semen from 84 of these donors. This included 67 participants in whom the quality of fresh semen could be compared with the previous donation, the day of the PCR-positive nasopharyngeal sampling and the first subsequent donation. Semen donations were cryopreserved following total semen (n = 26) or ready-to-use (n = 58) protocols. The presence of SARS-CoV-2 in cryopreserved samples was determined by reverse transcription PCR. Semen quality (volume, concentration and progressive motility) was evaluated in accordance with World Health Organization 2010 recommendations. SARS-CoV-2 virus was not detected in any cryopreserved total semen or ready-to-use samples. No significant differences in semen volume, concentration or progressive motility were observed between the last previous donation, the day of the positive PCR nasopharyngeal sampling and the first subsequent donation. The lack of detection of SARS-CoV-2 in semen samples from asymptomatic individuals infected with SARS-CoV-2 supports the safety of assisted human reproduction treatments using this type of sample.

Infection by human polyomaviruses JCPyV and BKPyV in blood donors of Argentina.

A spectrum of blood-borne infectious agents may be transmitted through transfusion of blood components from asymptomatic donors. Despite the persistence of polyomaviruses in blood cells, no studies have been conducted in Argentina to assess the risk of transfusion infection. We investigated BKPyV and JCPyV in 720 blood donors, using polymerase chain reaction (PCR) for a region of T antigen common to both viruses. Positive T-antigen samples were subjected to two additional PCR assays targeting the VP1 region. Viral genotypes were characterized by phylogenetic analysis. Polyomaviruses were detected in 1.25% (9/720) of the blood samples selected; JCPyV was identified in 0.97% (7/720) and BKPyV in 0.28% (2/720) of them. Phylogenetic analysis showed that the JCPyV sequences clustered with 2A genotype and Ia of BKPyV. This study describes for the first time the prevalence of polyomavirus DNA in blood donors of Córdoba, Argentina. The polyomavirus DNAemia in healthy populations suggests that those viruses are present in blood components eligible for transfusion. Therefore, the epidemiological surveillance of polyomavirus in blood banks might be incorporated into haemovigilance programmes, to determine the infectious risk and implement newer interventions to ensure the safety of blood supplies, if required.

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

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. 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. 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. 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.

Assessing SARS-CoV-2-specific T-cell reactivity in late convalescents and vaccinees: Comparison and combination of QuantiFERON and activation-induced marker assays, and relation with antibody status.

Monitoring of SARS-CoV-2 spread and vaccination strategies have relied on antibody (Ab) status as a correlate of protection. We used QuantiFERON™ (QFN) and Activation-Induced Marker (AIM) assays to measure memory T-cell reactivity in unvaccinated individuals with prior documented symptomatic infection (late convalescents) and fully vaccinated asymptomatic donors (vaccinees). Twenty-two convalescents and 13 vaccinees were enrolled. Serum anti-SARS-CoV-2 S1 and N Abs were measured using chemiluminescent immunoassays. QFN was performed following instructions and interferon-gamma (IFN-γ) measured by ELISA. AIM was performed on aliquots of antigen-stimulated samples from QFN tubes. SARS-CoV-2-specific memory CD4+CD25+CD134+, CD4+CD69+CD137+ and CD8+CD69+CD137+ T-cell frequencies were measured by flow cytometry. In convalescents, substantial agreement was observed between QFN and AIM assays. IFN-γ concentrations and AIM+ (CD69+CD137+) CD4+ T-cell frequencies correlated with each other, with Ab levels and AIM+ CD8+ T-cell frequencies, whereas AIM+ (CD25+CD134+) CD4+ T-cell frequencies correlated with age. AIM+ CD4+ T-cell frequencies increased with time since infection, whereas AIM+ CD8+ T-cell expansion was greater after recent reinfection. QFN-reactivity and anti-S1 titers were lower, whereas anti-N titers were higher, and no statistical difference in AIM-reactivity and Ab positivity emerged compared to vaccinees. Albeit on a limited sample size, we confirm that coordinated, cellular and humoral responses are detectable in convalescents up to 2 years after prior infection. Combining QFN with AIM may enhance detection of naturally acquired memory responses and help stratify virus-exposed individuals in T helper 1-type (TH1)-reactive (QFNpos AIMpos Abshigh), non-TH1-reactive (QFNneg AIMpos Abshigh/low), and pauci-reactive (QFNneg AIMneg Abslow).

Profile and Post-Kidney Retrieval Outcomes in Asymptomatic Kidney Donors With Genetic Mutations in Complement Factors–Related Genes

BackgroundAtypical hemolytic uremic syndrome (aHUS) is a rare disorder triggered by various stressors. Most of the time, stressors may not be identified in patients with aHUS. The disease may remain quiescent without manifestation throughout life. BackgroundTo assess the outcome of an asymptomatic carrier of genetic mutations of patients with aHUS who had undergone donor kidney retrieval surgery. MethodsWe retrospectively included the patients diagnosed with a genetic abnormality in complement factor H (CHF) or CHF-related (CFHR) genes without manifestation of the aHUS and who had undergone donor kidney retrieval surgery. The data were analyzed with descriptive statistics. ResultsAmong patients who were the kidney recipients from the prospective donors, 6 donors were screened for genetic mutations in CFH and CFHR genes. Four donors showed positive mutation for CFH and CFHR. The mean age was 54.5 years (range, 50-64 years). After over a year since donor kidney retrieval surgery, all prospective mother donors are alive without aHUS activation and with a normal kidney function on a single kidney. ConclusionAsymptomatic carriers of genetic mutations in CFH and CFHR can be the prospective donors for their first-degree family member who have active aHUS. A genetic mutation in an asymptomatic donor should not be a contraindication for refuting the prospective donor.

Risk of Helicobacter pylori transmission by faecal microbiota transplantation via oral capsules

ObjectivesThe aim was to determine if Helicobacter pylori is transmitted from donors to recipients by faecal microbiota transplantation (FMT) via oral capsules. MethodsIn a cohort of faeces donors not primarily screened for H. pylori, consecutive stool samples were retrospectively analysed by the H. pylori stool antigen test (SAT). Subsequently, we analysed recipient stool samples collected before and after receiving faeces donated by H. pylori SAT–positive donors, and we recorded recipient use of antibiotics and proton pump inhibitors. All stool samples were frozen upon collection and stored at −80°C until use. ResultsThirteen out of 40 faeces donors (33%; 95% CI, 20–48%) were H. pylori SAT–positive. Among those positive, five donors donated faeces for 28 capsule-based FMTs performed in 26 recipients with stool samples collected before and after FMT. At a median of 59 days (range, 7–84 days) after FMT, no recipients (0%; 95% CI, 0–11%) were H. pylori SAT–positive. DiscussionWe found no occurrence of H. pylori transmission from healthy, asymptomatic donors to recipients by oral capsule–based FMT, although with a wide CI.

The Prevelance of Hepatitis B Surface Antigen (HBsAg) Among Blood Donors in Some Hospitals of Thamar, Yemen

Viral hepatitis is a general term meaning inflammation of the liver and can be caused by a variety of viruses such as hepatitis B virus.
 Hepatitis B is a serious transfusion-transmissible disease affecting millions of people throughout the world.
 This study was designed to evaluate the prevalence of HBsAg and the risk factors for HBV infection among blood donors in Thamar governorate/Yemen, and to focus upon the importance of blood transfusion in spreading the hepatitis B virus.
 A total of 200 blood donors at the blood bank of Thamar hospital and Al-Wehda teaching hospital, during the period of January 2009 to October 2009, and January 2010 to July 2010, were screened for the presence of hepatitis B surface antigen (HBsAg) . Each patient filled a questionnaire including age, sex, dental visit, blood transfusion ..etc. The donors were all male adult (age: 17-45 years).
 Four out of 200 (2%) donors were found to be HBsAg positive by an enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies to HBsAg. Two of the four (50%) HBsAg-positive donors have relative symptoms of HBV (i.e jaundice) while the other two HBsAg-positive donors were asymptomatic. Questionnaires revealed that: The four positive donors were all married. The two asymptomatic HBsAg-positive donors were army soldiers. The other two symptomatic donors were civil workers.
 One of the two asymptomatic donors has donated a blood a year ago and found to be HBsAg negative.
 One of the symptomatic positive donors has had two previous surgical operations and received several pints of blood.
 This study emphasizes the need for an accurate detection of this virus, and the need for using confirmatory tests for HBsAg detection and also the need to undertake serious measures to control the spread of HBV among Yemeni people.

Seroprevalence of SARS-CoV-2 IgG antibodies among asymptomatic whole blood donors at a regional blood transfusion center and association of prevalence with ABO blood group

Background: Serological tests in asymptomatic donors provide may be a source of information on estimate of population-based infection. Serological tests using immunoglobulin G (IgG) can be a useful tool in assessing the disease’s spread if they are carried out serially in a regular manner. We analyzed the pattern in seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG in frequent intervals in an unvaccinated population. Aims and Objectives: This study aimed to study the prevalence of SARS-CoV-2 in asymptomatic blood donors in the period just before vaccine enrollment in Kerala and assess risk factors for SARS-CoV-2 positivity. Materials and Methods: The study was a cross-sectional study in which SARS-CoV-2 IgG positivity was estimated in blood donors attending Government Medical College, Trivandrum from February 1, 2021, to March 31, 2021. The participants responded to a questionnaire also about their demographic characteristics and risk factors. Data were analyzed in SPSS version 17. Results: The overall seroprevalence of COVID-19 anti-IgG antibody in blood donors was 26.4% (191/724). Periodic prevalence was 21.7% in the first half of February, 25.9% in the second half of February, 47.6% in the first half of March, and 25% in 2nd half of March 2021. Non-O group donors carried a higher risk for COVID seropositivity. Conclusion: The seroprevalence of SARS-CoV-2 was higher among the blood donors compared to the general population who were asymptomatic but it reflected the pattern in the general population. No specific risk factor among donor characteristics was identified which can predict seropositivity.

COVID-19 Convalescent Plasma Collection: A Cross-Sectional Study From the Perspective of Transfusion Medicine

Introduction: Convalescent plasma from cured symptomatic COVID-19 patients was one of the many treatment options rolled out during the COVID-19 pandemic. The high levels of viral neutralizing antibodies in plasma of those who had contracted the disease, and clinical improvement in viral pneumonias like Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) treated with convalescent plasma was the consideration behind this. Aim: To study recruitment including demographic characteristics of plasma donors, and recording any adverse donor reactions. Materials and Methods: This prospective cross-sectional study was conducted at the Department of Transfusion Medicine, Govt. Medical College, Kozhikode, Kerala, India from July 2020 to March 2021. All plasma donors who met the inclusion criteria as per the Kerala Government order permitting compassionate use of convalescent plasma were included in the study. Plasma collection was done using the Hemonetics MCS+ (MultiComponent System) Apheresis system and semiquantitative in-vitro determination of human antibodies, immunoglobulin class IgG against S1 domain of spike protein of SARS-CoV-2 was performed using EUROIMMUN anti-SARS CoV -2 ELISA. Results: Among the124 convalescent plasma donors, more than 90% donors were males of the age group 18-40 years and with a prior history of blood donation (repeat donors). Ninety donors (73%) had symptomatic COVID-19, 34 (27%) were asymptomatic. COVID-19 antibody determination showed 82 (66%) positive cases, 32 (26%) negative cases and 10 (8%) cases with borderline values. COVID-19 antibody was positive in 65 (72.2%) of the donors who were symptomatic compared to 17 (50%) asymptomatic donors. Adverse reactions were noted in 40 cases (32.26%), of which the procedure was discontinued in two. Conclusion: Donors with prior donation history and in the age group 18-40 years are more likely to donate. This study also showed a significant antibody response in symptomatic COVID-19 donors versus the asymptomatic. Low rate of serious adverse reactions amounting to stopping the procedure confirms its safety.