Symptomatic parvovirus B19 infection caused by blood component transfusion

Detection and analysis of parvovirus B19 among blood donors in a regional blood center in Eastern China

Background and objective

The B19 virus is mainly transmitted through the respiratory tract; however, studies have shown that it can also be transmitted through blood transfusions or plasma products. This study investigated B19V antibodies, DNA, and gene typing in blood donors at a central blood station in China to evaluate the status of B19V infection.

Materials and methods

A total of 7728 samples from Suzhou Blood Center were collected from July 2022 to April 2023. Samples were detected for the B19V DNA using real-time polymerase chain reaction. Furthermore, 893 selected samples were screened for the seroprevalence of B19V antibodies using enzyme-linked immunosorbent assay. The NS1-VP1u fragment of the B19V DNA-positive samples was amplified using nested PCR, and the sequences were determined. A B19V phylogenetic tree was constructed using neighborhood joint and maximum parsimony methods to discriminate genotypes using the NS1-VP1u sequences.

Results

The percentages of IgG, IgM, and DNA were 19.4 %, 1.9 %, and 0.09 %, respectively. IgG positivity increased with age, and there was a significant difference among the blood groups. The IgG levels of repeat donors were greater than those of first-time donors. There were no apparent differences in the IgM levels in all the participants. Genotyping revealed that the B19 genotype was 1.

Conclusions

The prevalence of B19V antibodies and DNA was lower in these areas than in rest of China, indicating that the risk of B19V transmission via transfusion may be relatively low. However, during transfusion, particular attention should be paid to the B19V-susceptible populations, especially those in high-risk groups.

Parvovirus B19 and Parvovirus 4 infections among healthy blood donors; A prevalence report from Iran

Background

Parvoviruses, characterized by their tropism for blood cells, can manifest as asymptomatic infections. With their ability to persist in blood, assessing the prevalence of Parvovirus B19 (B19V) and Parvovirus 4 (PARV4) among healthy blood donors is essential for evaluating the potential transmission risks through blood transfusions, emphasizing the need for comprehensive screening protocols.

Methods

Four hundred blood donors participated in the study, with their blood specimens subjected to Real-Time PCR analysis for B19V and PARV4 nucleic acids after obtaining informed consent. Additionally, Complete Blood Count (CBC) assessments and determination of anti-B19 V-IgM and anti-B19 V-IgG antibody titers were performed using Enzyme-Linked Immunosorbent Assay (ELISA) for all collected samples.

Results

The results reveal that 12 out of 400 individuals (3 %) exhibited positive results for B19V DNA, while 6 out of 400 individuals (1.5 %) tested positive for PARV4 DNA. Additionally, 8 out of 400 individuals (2 %) displayed positive results for anti-B19V IgM, and 306 out of 400 individuals (76.5 %) exhibited positive results for anti-B19 IgG. Notably, one donation from a donor presenting anti-IgM antibodies was subsequently confirmed as B19V DNA-positive through Real-Time PCR. In the analysis of CBC, a significant disparity in platelet levels was observed between B19V-positive donors, PARV4-positive donors, and B19V-negative donors.

Conclusions

The study suggests that individuals at high risk, lacking detectable B19V antibodies, should undergo systematic screening and exclusion. This precaution is intended to minimize potential contamination risks within the studied cohort, despite the undefined pathogenesis and clinical implications of PARV4.

Ensuring Transfusion Safety: Screening Blood Donors for Human Parvovirus B19

Ensuring the safety of blood and blood products is a vital aspect of healthcare. The potential for transmission of pathogens through blood and blood products makes transfusion safety a significant concern. Despite advancements in testing methodologies, donated blood products still pose a risk for infection transmission. Human parvovirus B19 (B19V) is a small, single-stranded, non-enveloped DNA virus transmissible parenterally by blood transfusion. B19V causes a wide range of clinical manifestations, which is generally harmless in healthy individuals. B19V infection may cause severe complications, such as aplastic crises, as it affects erythrocyte progenitor cells in individuals with increased erythrocyte turnover. Additionally, B19V can be transmitted from pregnant women to their foetus, potentially causing hydrops fetalis and foetal death. The potential for transmission through blood and blood products makes B19V a significant concern for transfusion safety. In response to the growing recognition of B19V's impact on transfusion safety, various international health organisations have introduced guidelines to minimise its transmission through blood and plasma products. However, the implementation of these guidelines varies globally, with some regions, such as India, still lacking formal protocols for B19V monitoring. This review article explores the existing methodologies for screening blood donors for B19V, assesses the associated transfusion risks, and considers the implications for public health and clinical practice. By emphasising advancements in diagnostic techniques and the challenges of their implementation, this article provides a comprehensive overview of efforts to reduce the transmission of B19V through blood transfusions, thereby ensuring safer blood supplies and improved patient outcomes.

Parvovirus B19 infection in pediatric allogeneic hematopoietic cell transplantation - Single-center experience and review

BACKGROUND

Parvovirus B19 (B19V) infection following pediatric hematopoietic cell transplantation (HCT) is a rare complication and available data is scarce. Therefore, we present the experience with B19V Infection in allogeneic pediatric HCT recipients at our transplant center together with a systematic review of the literature.

METHODS

Pediatric HCT patients with Parvovirus B19 infection treated at the University Children's Hospital Münster between 1999 and 2021 were retrospectively identified and clinical data were analyzed. Additionally, a systematic MEDLINE search to identify relevant articles was performed.

RESULTS

We identified three out of 445 patients (0.6%) with B19V infection post-transplantation. B19V infection occurred in combination with other complications like Graft-versus-Host disease, additional infections, or autoimmune-mediated hemolysis potentially triggered by B19V. In one patient these complications lead to a fatal outcome. The review of the literature showed considerable morbidity of B19V infection with the potential for life-threatening complications. Most patients were treated by red blood cell transfusion and intravenous immunoglobulins (IVIG) with a high succession rate.

CONCLUSION

Symptomatic B19V infection following HCT remains a rare but potentially challenging complication. A causal antiviral therapy does not exist as well as general recommendations on dosage and duration of IVIG therapy. Despite this, most patients are treated successfully with these measures. Additionally, transmission via blood or stem cell products is also rare and no general recommendations on B19V screenings exist.

Algorithm for laboratory diagnostics of parvoviral infection in risk groups

Parvovirus infection (PVI) is widespread, characterized by airborne, bloodborne and vertical transmission routes. Parvovirus B19 (PVB19) exhibits tropism to erythropoietic cells. According to the increased likelihood principle of PVB19 infection and the severity of the consequences, immunocompromised individuals, especially those with hematological manifestations of diseases, are in increased risk group. Based on the own research results and analysis of the published data, we have proposed specific algorithms for PVI laboratory testing in individual risk groups, taking into account the peculiarities of the development and infection manifestation in each group: in HIV-infected patients, in oncohematological patients with to whom allogeneic hematopoietic stem cell transplantation (allo-HSCT) have been prescribed (blood and bone marrow recipients), as well as in patients with chronic anemia of parasitic etiology. For each group, the main clinical or laboratory marker, treatment procedure, or patient physiological parameters have been determined, based on which it was recommended to test for PVI. For HIV-infected patients, the main criterion for PVI testing is persistent anemia. For oncohematological patients, the basis for PVI testing is allo-HSCT procedure, which is planned or performed for this particular patient. For malaria patients, the patient's age was considered as major criterion, since in malaria and PVI coinfected young children can lead to a fatal outcome. The proposed PVI diagnostics algorithms usein risk groups can help to predict the severe course of underlying disease associated with PVB19 infection, and timely correct the therapy used.

Wild Felids Blood Group System

Wild felids and domestic cats share the AB blood group. However, there have been few studies regarding the characterization and prevalence of the different blood types in wild animals. The erythrocyte membrane glycolipids of the wild cats correspond to the major disialoganglioside patterns observed in domestic cats. Like in domestic cats, type A blood seems to be the most common, although wild felid species seem to exhibit one single blood type. Of the species studied, the wild domestic cats, and the Panthera and ocelot lineages, all had type A blood; the Puma lineage showed almost exclusively type B blood. The prevalence of wild felids blood types show that there seems to be variation between species, but not within species, and no evidence of geographical variation has yet been found, showing apparently no genetic variability. The presence of alloantibodies has also been demonstrated, so the risk of life-threatening transfusion reactions due to mismatched transfusions and neonatal isoerythrolysis is a possibility. Like in other species, the recognition of wild felids blood groups is clinically relevant, as it can also be important in establishing phylogenetic relationships within the Felidae family. We will review the current knowledge on this topic and give insights into the wild felids blood groups potential for zoo transfusion medicine and phylogenetic studies in order to help support reintroduction projects and to preserve genetic diversity.

Prevalence and Phylogenetic Analysis of Parvovirus (B19V) among Blood Donors with Different Nationalities Residing in Qatar

Human parvovirus (B19V) is the causative agent of erythema infectiosum in children and is linked to a wide range of clinical manifestations. Studies related to B19V prevalence in the Middle East and North Africa (MENA) region and other parts of Asia are very scarce. The objectives of this study were to estimate the seroprevalence (anti-B19V IgM and IgG), the viremia rate (B19V DNA), and the circulating genotypes of B19V among blood donors in Qatar.

METHODS

Donors' blood samples (n = 5026) from different nationalities, mainly from the MENA region and South East Asia, were collected from 2014-2016. Samples were tested for the B19V DNA using RT-PCR. Furthermore, 1000 selected samples were tested to determine the seroprevalence of B19V antibodies using enzyme-linked immunosorbent assay (ELISA). Genotyping was performed on 65 DNA positive samples by sequencing of nested PCR fragments (NS1-VP1u region, 927 nt).

RESULTS

Only 1.4% (70/5026) of the samples had detectible B19V DNA in their blood. B19V DNA prevalence statistically decreased with age (p = 0.03). Anti-B19V IgG was detected in 60.3% (561/930) of the tested samples, while only 2.1% (20/930) were IgM-positive and 1.2% (11/930) were both IgM- and IgG-positive. B19V genotyping showed a predominance of Genotype 1 (100%). Sequence analysis of the NS1-VP1u region revealed 139 mutation sites, some of which were amino acid substitutions.

CONCLUSION

Our results indicated a relatively high seroprevalence of B19V in Qatar. Most importantly, B19 DNA was detected among Qatari and non-Qatari blood donors. Therefore, blood banks in Qatar might need to consider screening for B19V, especially when transfusion is intended for high-risk populations, including immunocompromised patients.

Serosurvey of parvovirus B19 and cytomegalovirus infections among female university students in Shiraz, Southern Iran

Infection with parvovirus B19 and cytomegalovirus (CMV) during pregnancy might lead to fetal infection, resulting in congenital abnormalities. This study aimed to investigate the frequency of IgM and IgG antibodies against parvovirus B19 and CMV in female university students in Shiraz, in Fars province, Southern Iran. In this cross-sectional study, 370 female university students were included. Blood samples were collected from each participant and tested for anti-parvovirus B19 and CMV IgG and IgM antibodies, using commercial ELISA kits. The mean age of the participants was 24 (±7)years. Out of 370 participants, 327 (88.4%) and 9 (2.4%) were positive for IgG and IgM antibodies against CMV. Moreover, 211 (57.0%) and 4 (1.1%) of the participants were respectively positive for IgG and IgM antibodies against parvovirus B19. The difference in CMV or parvovirus B19 seropositivity between different age groups was not statistically significant (P>0.05). The findings of our study showed that more than 50% of the female university students are seropositive to CMV and parvovirus B19 infections. It highlights the importance of health education and also the laboratory screening of females at childbearing age to reduce the risk of congenital infections resulting from these viral infections.

Enhanced Cell-Based Detection of Parvovirus B19V Infectious Units According to Cell Cycle Status

Human parvovirus B19 (B19V) causes various human diseases, ranging from childhood benign infection to arthropathies, severe anemia and fetal hydrops, depending on the health state and hematological status of the patient. To counteract B19V blood-borne contamination, evaluation of B19 DNA in plasma pools and viral inactivation/removal steps are performed, but nucleic acid testing does not correctly reflect B19V infectivity. There is currently no appropriate cellular model for detection of infectious units of B19V. We describe here an improved cell-based method for detecting B19V infectious units by evaluating its host transcription. We evaluated the ability of various cell lines to support B19V infection. Of all tested, UT7/Epo cell line, UT7/Epo-STI, showed the greatest sensitivity to B19 infection combined with ease of performance. We generated stable clones by limiting dilution on the UT7/Epo-STI cell line with graduated permissiveness for B19V and demonstrated a direct correlation between infectivity and S/G2/M cell cycle stage. Two of the clones tested, B12 and E2, reached sensitivity levels higher than those of UT7/Epo-S1 and CD36⁺ erythroid progenitor cells. These findings highlight the importance of cell cycle status for sensitivity to B19V, and we propose a promising new straightforward cell-based method for quantifying B19V infectious units.

Viral metagenomics in blood donations with post-donation illness reports from Brazil

BACKGROUND

Post-donation illness can be described as appearance of clinical symptoms in blood donors after donation. The consequent call back of the donor to report these symptoms to the blood collection institution is considered a post-donation illness report (PDIR). The most suitable way to examine whether PDIR is related to infection is to apply next-generation sequencing (NGS) and viral metagenomics. Investigation into a PDIR can reveal its importance for transfusion safety and help elaborate strategies for donor education in order to prevent the transfusion transmission of infections which are not routinely tested by the blood collection services.

MATERIALS AND METHODS

We applied NGS and viral metagenomics on blood donations which were deferred due to a PDIR. Thirty-three PDIR donations obtained in the Blood Center of Ribeirão Preto, Southeast Brazil, were evaluated. Sequencing was performed using Illumina NextSeq 550 (Illumina Inc, San Diego, CA, USA) equipment and the reads obtained for each sample were analysed by specific bioinformatic pipeline for the classification and discovery of emerging viruses. The identified viral agents by metagenomics were directly confirmed by molecular methods.

RESULTS

In all PDIR donations, we found abundant reads of commensal viruses belonging to the Anelloviridae family as well as human pegivirus-1. However, we were also able to identify blood donations positive for clinically important viruses like dengue serotype-2 (DENV-2) of the Asian-American genotype and parvovirus B19 (B19V). Both viruses were also confirmed by real-time polymerase chain reaction, detecting DENV-2 RNA in a significant number of cases (7 samples, 21.2%), compared to B19V which was confirmed in 1 case (3.0%).

DISCUSSION

Our study applies for the first time viral metagenomics to evaluate the significance of PDIRs. We confirm the crucial importance of the donor providing a timely PDIR for the prevention of transfusion transmission of viral infections which are not routinely tested in the blood banks worldwide.

Overall prevalence of human parvovirus B19 among blood donors in mainland China: A PRISMA-compliant meta-analysis

BACKGROUND

Human parvovirus B19 (B19V) infection exhibits a broad range of clinical outcomes. Blood transfusion is a common route of B19V transmission. However, information about the overall prevalence of B19V infection and B19V genotypes among blood donors in mainland China is lacking.

METHODS

This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search for studies reporting the B19V prevalence among blood donors in mainland China from 2000 to 2018 was performed. The prevalence of B19V was estimated through a meta-analysis of the relevant literature. A comprehensive meta-analysis program was used for data processing and statistical analysis.

RESULTS

Twenty-one eligible articles were included, involving 48,923 participants assessed for B19V-DNA, 12,948 participants assessed for anti-B19V immunoglobulin M (IgM), and 8244 participants assessed for anti-B19V immunoglobulin G (IgG). The analysis revealed the pooled estimates of the prevalence rates of B19V-DNA, anti-B19V IgM, and anti-B19V IgG among blood donors to be 0.7% (95% confidence interval [CI] 0.2-2.4%), 2.7% (95% CI 1.7-4.3%), and 33.6% (95% CI 28.2-39.4%), respectively. Moreover, phylogenetic analyses indicated that 142 of 169 (84.0%) B19V isolates belonged to Genotype 1.

CONCLUSIONS

The overall prevalence of B19V among blood donors is not high in mainland China, and most isolates belong to Genotype 1.

The human parvovirus B19/human immunodeficiency virus co-infection in healthy eligible voluntary blood donors at the Blood Transfusion National Center in Kinshasa

Introduction

Parvovirus B19 (PVB19) is one of several viruses transmissible by blood transfusion. Levels of exposure to PVB19 among HIV-infected voluntary blood donors are comparable to those among HIV-negative controls because, in blood donors, the PVB19 infection is transmitted mainly via the respiratory route. Thus, we hypothesize that the seroprevalence of PVB19 in HIV-positive blood donors is equal to the seroprevalence of PVB19 in HIV-negative blood donors. The objective of this study was to compare the seroprevalence of PVB19 between asymptomatic HIV-positive and HIV-negative blood donors.

Methods

A random sample of 360 eligible blood donors were firstly examined for HIV antibodies by using ELISA automaton and so were categorized as HIV-positive donors and HIV-negative donors. Then the two categories of donors were examined for PVB19 IgG and IgM by using ELISA kits. The seroprevalence of PVB19 in HIV-positive donors was compared to that of HIV-negative donors by using chi-square test or Fisher's exact test. All statistical analyzes were performed with SPSS 21.

Results

The prevalences of PVB19 IgG and IgM in HIV-positive blood donors were 92.1% (35 of 38) and 44.7% (17 of 38), respectively and those in control group were 89.1% (287 of 322) and 46.3% (149 of 322), respectively. But for both IgG and IgM the difference was not statistically significant (p > 0.05).

Conclusion

This research confirms our hypothesis: the seroprevalence of PVB19 in HIV-positive blood donors is equal to the seroprevalence of PVB19 in HIV-negative blood donors.

An assessment of the risk, cost-effectiveness, and perceived benefits of anti-parvovirus B19 tested blood products

BACKGROUND

Parvovirus B19 (B19V) can cause severe anemia, hydrops foetalis, and even death in vulnerable patients. To prevent transfusion-transmitted B19V infection of at-risk patients, B19V antibody screening of blood donors was implemented. The cost-effectiveness of this intervention is unclear, as the likelihood of transmission through blood and subsequent complications for recipients are unknown. This study estimates the cost-effectiveness of anti-B19V donor screening in the Netherlands.

STUDY DESIGN AND METHODS

The estimates needed for the cost-effectiveness model were: the occurrence of B19V in Dutch blood donors, the number of anti-B19V tested products required by hospitals, the likelihood of morbidity and mortality given B19V infection, treatment costs, and screening costs. These estimates were obtained from literature and observational data. When data were unavailable, structured expert judgment elicitation and statistical modeling were applied.

RESULTS

The costs of preventing one transfusion transmitted B19V infection are estimated at €68,942 (€42,045 - €102,080). On average, 1.25 cases of morbidity and 0.12 cases of mortality are prevented annually. Although the perceived risk of transfusion transmitted B19V infection was low, half of the treating physicians favored anti-B19V screening.

CONCLUSION

The estimated mortality and morbidity caused by B19V infection was low in the risk groups. The cost-effectiveness ratio is similar to other blood safety screening measures. No guidance exists to evaluate the acceptability of this ratio. The explicit overview of costs and effects may further guide the discussion of the desirability of B19V safe blood products.

Parvovirus B19 seroprevalence, viral load, and genotype characterization in volunteer blood donors from southern Brazil

Usually transmitted via respiratory droplets, parvovirus B19 (B19V) can also be acquired by blood transfusion especially because of viral persistence, resistance to blood treatment procedures, and high viral load during the early infection phase. This is particularly problematic in immunocompromised or anemic patients where the infection can have a severe outcome. As B19V DNA was detected in blood donations from South Brazil during a viral metagenomic survey performed by Next-Generation Sequencing, the objective of this retrospective study was to evaluate the seroprevalence, B19V DNA presence and circulating genotypes in a Hospital Blood Transfusion Service in Santa Maria city in South Brazil (Rio Grande do Sul state). Among 480 volunteer blood donors, 53.9% (n = 258 of 479) were anti-B19V IgG-positive, and 9 (1.9%) plasma samples presented B19V DNA. In almost all cases (n = 7 of 9, 77.8%), B19V DNA load was accompanied by the presence of anti-B19V IgG suggesting a persistent infection. The sequencing of the strains demonstrated that all belong to genotype 1 which is the most prevalent worldwide. The analysis of the recipient information of the positive for B19V DNA units revealed no related posttransfusion adverse effects. Our results demonstrate for the first time, B19V seroprevalence, viral load, and genotypes among blood donors from South Brazil and give a light for the circulation and impact of this B19V in this part of the country.

Parvovirus B19 in South African blood donors

BACKGROUND

Parvovirus B19 (PVB19) is transmitted via transfusion of blood and blood products. PVB19 is resistant to viral inactivation methods, which poses a threat to blood safety. We investigated the prevalence of PVB19 antibodies and DNA in healthy blood donors from the South African National Blood Bank Service to evaluate the necessity of PVB19 DNA testing.

STUDY DESIGN AND METHOD

A retrospective analysis of 1500 residual plasma specimens from healthy blood donors from the SANBS repository were screened in mini-pools of 20 for PVB19 DNA using a quantitative polymerase chain reaction (PCR). Positive pools were resolved by individual viral load testing and screened for PVB19 immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies to correlate viral loads with serological status. PVB19 IgG prevalence was determined by testing 90 randomly selected specimens from the 1500 plasma specimens.

RESULTS

The prevalence of PVB19 IgG, IgM and IgG, and DNA was 62.2%, 0.06%, and 0.9%, respectively. Fourteen of the 1500 blood donor specimens received, had detectable PVB19 viral loads. Nine of the fourteen donors with detectable viral loads were PVB19 IgG seropositive. The PVB19 viral loads ranged from 1.81 to 5.32 log IU/mL. Four of the fourteen viraemic donors had a viraemia >10 ⁴ IU/mL.

CONCLUSION

We have demonstrated a low prevalence of PVB19 DNA in SANBS blood donors. The predominance of low-level viraemia and the presence of PVB19 antibodies, suggests that the risk of transfusion transmission of PVB19 among SANBS donors may be relatively low.

Seroprevalence of antibodies to primate erythroparvovirus 1 (B19V) in Australia

Backgroud

Primate erythroparvovirus 1 (B19V) is a globally ubiquitous DNA virus. Infection results in a variety of clinical presentations including erythema infectiosum in children and arthralgia in adults. There is limited understanding of the seroprevalence of B19V antibodies in the Australian population and therefore of population-wide immunity. This study aimed to investigate the seroprevalence of B19V antibodies in an Australian blood donor cohort, along with a cohort from a paediatric population.

Methods

Age/sex/geographical location stratified plasma samples (n = 2221) were collected from Australian blood donors. Samples were also sourced from paediatric patients (n = 223) in Queensland. All samples were screened for B19V IgG using an indirect- enzyme-linked immunosorbent assay.

Results

Overall, 57.90% (95% CI: 55.94%–59.85%) of samples tested positive for B19V IgG, with the national age-standardized seroprevalence of B19V exposure in Australians aged 0 to 79 years estimated to be 54.41%. Increasing age (p < 0.001) and state of residence (p < 0.001) were independently associated with B19V exposure in blood donors, with the highest rates in donors from Tasmania (71.88%, 95% CI: 66.95%–76.80%) and donors aged 65–80 years (78.41%, 95% CI: 74.11%–82.71%). A seroprevalence of 52.04% (95% CI: 47.92%–56.15%) was reported in women of child-bearing age (16 to 44 years). Sex was not associated with exposure in blood donors (p = 0.547) or in children (p = 0.261) screened in this study.

Conclusions

This study highlights a clear association between B19V exposure and increasing age, with over half of the Australian population likely to be immune to this virus. Differences in seroprevalence were also observed in donors residing in different states, with a higher prevalence reported in those from the southern states. The finding is consistent with previous studies, with higher rates observed in countries with a higher latitude. This study provides much needed insight into the prevalence of B19V exposure in the Australian population, which has implications for public health as well as transfusion and transplantation safety in Australia.

Seroprevalence, molecular epidemiology and quantitation of parvovirus B19 DNA levels in Iranian blood donors

Human parvovirus B19 (B19) infection is common among blood donors, and healthy blood donors can transmit virus via transfusion. Due to resistance of B19 to viral inactivation methods, there is a potential concern regarding transfusion safety in blood products. We aimed to determine the seroprevalence, molecular epidemiology, and quantitation of B19 DNA levels in blood donors in Tehran, Iran. A total of 500 blood donors from Blood Transfusion Research Center were studied. ELISA was used for detection of B19 IgG and IgM and nested PCR was carried out for detection of B19 DNA. PCR products were subjected to direct sequencing. B19 viral load was determined by real time PCR. B19 IgG, IgM, and DNA were detected in 27.6, 2.6, and 1.2% of donors respectively. Ten samples (2%) were positive for both antibodies while in four cases (0.8%), B19 IgG and DNA detected simultaneously. One case had B19 IgM, IgG, and viremia concurrently. The titers of B19 DNA in four of six donors were more than 106 IU/mL (high level viremia) and all four cases had IgG simultaneously. All B19 isolates categorized in genotype 1A. Our findings indicated that prevalence of B19 DNA in Iranian blood donors was comparable with previous studies throughout the world. High level B19 viremia found in 0.8% of our donors and all viremic donors revealed neutralizing B19 antibody. Therefore implementation of a B19 screening test for each volunteer blood donor does not appear to be necessary but B19 testing for plasma‐derived products seems important in Iranian donors.

Parvovirus B19: What Is the Relevance in Transfusion Medicine?

Parvovirus B19 (B19V) has been discovered in 1975. The association with a disease was unclear in the first time after the discovery of B19V, but meanwhile, the usually droplet transmitted B19V is known as the infectious agent of the “fifth disease,” a rather harmless children’s illness. But B19V infects erythrocyte progenitor cells and thus, acute B19V infection in patients with a high erythrocyte turnover may lead to a life-threatening aplastic crisis, and acutely infected pregnant women can transmit B19V to their unborn child, resulting in a hydrops fetalis and fetal death. However, in many adults, B19V infection goes unnoticed and thus many blood donors donate blood despite the infection. The B19V infection does not impair the blood cell counts in healthy blood donors, but after the acute infection with extremely high DNA concentrations exceeding 10¹⁰ IU B19V DNA/ml plasma is resolved, B19V DNA persists in the plasma of blood donors at low levels for several years. That way, many consecutive donations that contain B19V DNA can be taken from a single donor, but the majority of blood products from donors with detectable B19V DNA seem not to be infectious for the recipients from several reasons: first, many recipients had undergone a B19V infection in the past and have formed protective antibodies. Second, B19V DNA concentration in the blood product is often too low to infect the recipient. Third, after the acute infection, the presence of B19V DNA in the donor is accompanied by presumably neutralizing antibodies which are protective also for the recipient of his blood products. Thus, transfusion-transmitted (TT-) B19V infections are very rarely reported. Moreover, in most blood donors, B19V DNA concentration is below 1,000 IU/ml plasma, and no TT-B19V infections have been found by such low-viremic donations. Cutoff for an assay for B19V DNA blood donor screening should, therefore, be approximately 1,000 IU/ml plasma, if a general screening of blood donors for single donation blood components is considered at all: for the overwhelming majority of transfusion recipients, B19V infection is not relevant as well as for the blood donors. B19V DNA screening of vulnerable patients after transfusion seems to be a more reasonable approach than general blood donor screening.

Parvovirus B19 in the Context of Hematopoietic Stem Cell Transplantation: Evaluating Cell Donors and Recipients

Background

Parvovirus B19 (B19V) is a common human pathogen, member of the family Parvoviridae. Typically, B19V has been found to infect erythroid progenitors and cause hematological disorders, such as anemia and aplastic crisis. However, the persistence of genomic deoxyribonucleic acid (DNA) has been demonstrated in tonsils, liver, skin, brain, synovial, and testicular tissues as well as bone marrow, for both symptomatic and asymptomatic subjects. Although the molecular and cellular mechanisms of persistence remain undefined, it raises questions about potential virus transmissibility and its effects in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients.

Methods

With this aim, we retrospectively screened allogeneic stem cell donors from 173 patients admitted for allo-HSCT from January 2008 to May 2013 using a seminested polymerase chain reaction approach.

Results

We found 8 positive donor samples, yielding a 4.6% of parvovirus prevalence (95% confidence interval, 2.36-8.85). Pre- and post-HSCT samples (n = 51) from the 8 recipients of the positive donors were also investigated, and 1 case exhibited B19V DNA in the post-HSCT follow-up (D + 60). Direct DNA sequencing was performed to determine the genotype of isolates and classification, performed by phylogenetic reconstruction, showed a predominance of genotype 1a, whereas the rare genotype 3b was detected in 2 additional patients. By molecular cloning, different B19V 1a substrains polymorphisms were evidenced in the single case in which donor and its recipient were B19V+.

Conclusions

Our results suggest that HSCT allografts are not a main source for B19V transmission, pointing to potential events of reinfection or endogenous viral reactivation.

[Risk of transmission of blood-derived pathogens by transfusion in Poland]

Blood transfusion in Poland is the safest in history. High virological level of safety has been achieved mainly by improving not only the qualification of donors and methods used for donor screening, but also applying leukoreduction, pathogen reduction technology and grace period for serum.In this article, we discuss the improvement of the epidemic situation among blood donors for hepatitis B virus (HBV) and hepatitis C virus (HCV) and the increasing trend for HIV. Preliminary results of residual risk calculation for these pathogens are presented.Hepatitis E virus (HEV) and Babesia microti were considered as new factors potentially relevant for the safety of blood transfusion in our country. Due to evidence of West Nile virus (WNV) circulation in the ecosystem in Poland, it is also necessary to monitor the infections with this pathogen.In this article, it was emphasized that the reporting of all possible complications associated with transfusion and meticulous implementation of the look-back procedure play a key role for monitoring the risk of transmission of infectious agents by blood. It is especially important in view of the increasing epidemiological problems associated with emerging infectious agents.

Persistent symptomatic parvovirus B19 infection with severe thrombocytopenia transmitted by red blood cell transfusion containing low parvovirus B19 DNA levels

BACKGROUND

Transfusion-mediated human parvovirus B19 (PVB19) infection is rare but often causes severe hematologic disorders. In Japan, routine blood donor screening for PVB19 antigen (detection sensitivity, 10^6.4 IU/mL) using a chemiluminescent enzyme immunoassay (CLEIA) was introduced in 2008. However, there is no consensus on the minimal infectious dose of PVB19 permissible for red blood cells (RBCs).

CASE REPORT

A 64-year-old man, who had received hemodialysis for diabetic nephropathy for 5 years, underwent an RBC transfusion for anemia caused by hemorrhagic enterocolitis. He developed persistent high fever and progressive thrombocytopenia. He was diagnosed with PVB19 infection when a marrow examination showed giant erythroblasts, and his serum was positive for PVB19 DNA. His serum was negative for PVB19 immunoglobulin (Ig)M and IgG before transfusion, but positive for both after transfusion. This PVB19 infection was deemed to be transmitted by the RBC transfusion because low levels of PVB19 DNA (1.10 × 10⁴ IU/mL) were detected in one of the blood donors. A DNA homology test of PVB19 showed complete genomic identity between the virus in the donor and our patient.

CONCLUSION

We report a patient who developed persistent PVB19 infection from an RBC transfusion containing low levels of PVB19. This is the second case of transfusion-mediated PVB19 infection since the introduction of CLEIA in 2008. Transmission may occur in immunocompromised patients lacking PVB19-neutralizing antibodies. The report of further such cases will allow the establishment of minimal threshold values and more effective screening tests for PBV19 transmission through RBC products.

Human parvovirus B19 in patients with beta thalassemia major from Tehran, Iran

Background

Due to the tropism of human parvovirus B19 to erythroid progenitor cells, infection in patients with an underlying hemolytic disorder such as beta-thalassemia major leads to suppression of erythrocyte formation, referred to as transient aplasia crisis (TAC), which may be life-threatening. We investigated the prevalence of parvovirus B19 among patients with beta thalassemia major attending the Zafar Adult Thalassemia Clinic in Tehran, Iran.

Methods

This cross-sectional study was performed to determine the presence of parvovirus B19 DNA in blood samples and parvovirus B19 genotypes in plasma samples of patients with thalassemia major. The population consisted of 150 patients with beta-thalassemia major who attended the Zafar clinic in Tehran. Specimens were studied using a real-time polymerase chain reaction assay.

Results

The prevalence of parvovirus B19 in our study population was 4%. Of 150 patients with thalassemia, six (4%) were positive for B19 DNA. There was no significant correlation between blood transfusion frequency and B19 DNA positivity. Finally, phylogenetic analysis of human parvovirus B19 revealed genotype I in these six patients.

Conclusion

In this study, acute B19 infections were detected in patients with beta thalassemia major. Screening of such high-risk groups can considerably reduce the incidence and prevalence of B19 infection; thus, screening is required for epidemiologic surveillance and disease-prevention measures.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

Parvovirus B19 Passive Transmission by Transfusion of Intercept® Blood System-Treated Platelet Concentrate

BACKGROUND

Pathogen reduction methods for blood components are effective for a large number of viruses though less against small, non-enveloped viruses such as Parvovirus B19 (B19V). This article describes the passive transmission by transfusion of two B19V-contaminated pooled platelet concentrates (PCs) which were treated with the Intercept® blood pathogen reduction system.

CASE REPORTS

Two transfusion cases of B19V-contaminated Intercept-treated pooled PCs were described. Due to the analysis delay, the PCs were already transfused. The viral content of each donation was 4.87 × 10(10) IU/ml in case 1and 1.46 × 10(8) IU/ml in case 2. B19V (52 IU/ml) was detected in the recipient of the case 1 PC, whereas no virus could be detected in the case 2 PC recipient. A B19V IgM response and a transient boost of the underlying B19V IgG immune status and was observed in recipient 1. Recipient of the case 2 PC remained B19V IgG- and IgM-negative. B19V DNA sequence and phylogenetic analysis revealed a 100% homology between donor and recipient.

CONCLUSION

This report describes passive B19V transmission by a PC with very high B19 viral load which elicited a transient boost of the B19V immunity, but not by a PC with a lower B19V content, suggesting that there is a B19 viral load threshold value at which B19V inactivation is exceeded.

The prevalence of hepatitis A virus and parvovirus B19 in source-plasma donors and whole blood donors in China

AIMS

To compare the prevalence of hepatitis A virus (HAV) and human parvovirus B19 (B19V) between source-plasma (SP) donors and whole blood (WB) donors.

BACKGROUND

In China, source plasma is in severe shortage while plasma recovered from WB is in surplus. Thus, the government is considering transferring the recovered plasma (RP) to produce plasma derivatives. HAV and B19V are two pathogens threatening the safety of plasma-based derivatives. However, there is no data about if transferring of the RP to produce plasma derivatives will increase the risk of HAV and B19V infection. Thus, we compared the prevalence of HAV and B19V between SP donors and WB donors in this study.

METHODS

A total of 5030 samples from SP donors and 5040 samples from WB donors were collected. All the samples were tested for HAV RNA and B19V DNA and tested for HAV IgM by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The prevalence of B19V DNA was 0.06% (95% confidence interval (CI), 0-0.09%) in WB donors and 0.079% (95% CI, 0-0.12%) in SP donors, respectively. No significant difference was found in the prevalence of B19V DNA between SP donors and WB donors. The prevalence of anti-HAV IgM in SP donors was 0.079% whereas no WB donor sample was found anti-HAV IgM reactive.

CONCLUSIONS

The transfer of RP to producing plasma derivatives will not increase the risk of transmission of HAV and B19 through plasma products.

Look-back study on recipients of Parvovirus B19 (B19V) DNA-positive blood components

BACKGROUND AND OBJECTIVES

To assess the relevance of Parvovirus B19 (B19V) DNA at low to intermediate concentrations in blood donors for the recipients of their blood components.

MATERIAL AND METHODS

We studied recipients of B19V DNA-positive blood components [red blood cell concentrates (RBCs), pooled platelet concentrates and fresh frozen plasma]. This included archived pretransfusion samples as well as follow-up samples investigated by ELISA or NAT and genome sequence analysis.

RESULTS

In 132 out of 424 recipients, we could detect no anti-B19V IgG before transfusion. In 67 out of 132 sero-negative recipients, a follow-up sample was available. Sixty-five of these received blood components from donors with <10(4) IU B19V DNA/ml plasma and had no evidence of transfusion-transmitted (TT)-B19V infection. Homology in genome sequences in donor and recipient provided evidence for a TT-B19V infection in two recipients. Both patients received RBC containing 3.4 × 10(6) and 1.8 × 10(4) IU B19V DNA/ml plasma, respectively. The anti-B19V IgG titres in the donors were 2 and 76 IU/ml plasma, respectively. The antibodies in the second donor were directed against capsid proteins and are thus considered as potential neutralizing antibodies.

CONCLUSIONS

TT-B19V infections through blood components with low (<10(4) IU/ml plasma) B19V DNA concentrations did not occur in our study. One of the TT-B19V infections occurred from RBC with intermediate B19V DNA concentration despite the presence of potential neutralizing antibodies in the donor, but its clinical significance was low.

The genomic and seroprevalence of human bocavirus in healthy Chinese plasma donors and plasma derivatives

BACKGROUND

Human bocavirus (HBoV) is a novel parvovirus identified in 2005. It has mostly been detected in respiratory and enteric infections and has not been studied large scale in blood products in relation to transfusion.

STUDY DESIGN AND METHODS

An in-house quantitative polymerase chain reaction (Q-PCR) was developed to test HBoV DNA in plasma and plasma derivatives. Plasma samples (n = 6096) collected from healthy donors, 241 plasma pools, and 326 plasma derivatives were screened for HBoV DNA by Q-PCR. Positive samples were confirmed by nested PCR and further amplified for sequence analysis and phylogenetic studies. The prevalence of immunoglobulin (Ig)G and IgM specific to HBoV structural proteins was measured by enzyme-linked immunosorbent assay in 209 samples grouped according to virus load (Group 1, HBoV DNA >10(4) copies/mL; Group 2, HBoV DNA >5 × 10(2) copies/mL but below 10(4) copies/mL; Group 3,HBoV DNA negative).

RESULTS

The genomic prevalence of HBoV in the plasma donors was 9.06%, ranging from 5.01 × 10(2) to 3.02 × 10(6) copies/mL. HBoV-specific IgG and IgM were detected at 20.00 and 7.50% in Group 1, at 20.29 and 2.90% in Group 2, and at 13.00 and 4.0% in Group 3, respectively. Phylogenetic analyses proved that HBoV Genotype 1 was the prevalent genotype in Chinese plasma donors.

CONCLUSION

Low levels of HBoV DNA were detectable at high prevalence in Chinese plasma donors and plasma derivatives. Further study is needed to determine whether HBoV screening is necessary.

Persistence of Parvovirus B19 (B19V) DNA and humoral immune response in B19V-infected blood donors

BACKGROUND AND OBJECTIVES

Parvovirus B19 (B19V) DNA seems to persist in the plasma of B19V-infected blood donors. The relevance of this for recipients of single-donor blood components is yet unclear.

MATERIAL AND METHODS

We studied serial archive and follow-up samples from 75 B19V-infected blood donors to obtain more data about the duration and degree of viraemia and the presence of IgG and IgM anti-B19V. IgG antibodies were further characterized by Western blot analysis in 29 donors.

RESULTS

In 411 B19V DNA-positive samples collected, we found high concentrations (>10(6) IU B19V DNA/ml plasma) in five. B19V DNA persisted for a mean of 21·5 months (range: 2·3-52·4; 95% confidence interval, 19·1-23·9 months) in all donors. Only 15 such samples had either no or low-titre IgG anti-B19V. IgG antibodies were predominantly directed against epitopes on the minor capsid protein VP1, thus probably of neutralizing type with high avidity. IgM anti-B19V was detectable in 9/13 samples with high DNA concentrations.

CONCLUSIONS

The vast majority of single-donor blood components with detectable B19V DNA are probably not infectious for their recipients because DNA is at only low levels and the donors also have potentially neutralizing antibodies with high avidity. Anti-B19V IgM testing does not identify every donation with high B19V DNA concentrations, but, in addition to B19V NAT testing, donors with persistent IgG anti-B19V might be considered 'B19V-safe' for single-donor blood components.

Parvovirus b19 infections and blood counts in blood donors

OBJECTIVES

Parvovirus B19 (B19V) is a transfusion-transmissible virus. To obtain data about the prevalence, incidence, the course of B19V infection in blood donors and whether B19V might impair their blood counts, samples from blood donors with B19V infection were investigated.

METHODS

Blood donations were screened for B19V DNA using the Cobas TaqScreen DPX Test® in mini-pools. B19V DNA concentration, anti-B19V IgG antibody titer and blood counts were determined in positive donors.

RESULTS

157/23,889 (0.66%) donors provided 347 B19V DNA-positive samples. Prevalence of B19V infection was 0.45%, incidence 0.20%. B19V DNA concentrations were predominantly low; only in 8 samples were viral loads of ≥10(5) IU B19V DNA/ml plasma detectable. Besides a slight decrease in hemoglobin, hematocrit, mean corpuscular volume, mean cellular hemoglobin and mean hemoglobin concentration, no major differences in blood counts occurred in B19V DNA-positive samples. In samples with a low B19V DNA concentration, anti-B19V IgG titers were rather high. 98 donors provided at least 1 B19V DNA-positive follow-up sample, indicating a prolonged viremia.

CONCLUSIONS

B19V infection induced no major impairment in the blood counts. In donors with low-level viremia, infectivity through their donations is probably reduced by high antibody titers. Low-level viremia is prolonged, probably exceeding 1 year in many cases.

Parvovirus B19V DNA contamination in Chinese plasma and plasma derivatives

Background

To ensure the safety of plasma derivatives, screening for human parvovirus B19V genomic DNA in donated plasma using a pooling strategy is performed in some countries. We investigated the prevalence of B19V DNA and anti-B19V antibodies in Chinese plasma pools, plasma derivatives and plasma donations to evaluate the risk posed by B19V.

Methods

Using a Q-PCR assay developed in-house, we tested for B19V genomic DNA in 142 plasma pools collected between January 2009 and June 2011 from two Chinese blood products manufacturers. Plasma derivatives collected between 1993–1995 (10 batches of albumin, 155 batches of intravenous immunoglobulin, IVIG) and 2009–2011 (50 batches of albumin, 54 batches of IVIG, 35 batches of factor VIII, 7 batches of fibrinogen, and 17 batches of prothrombin complex concentrate, PCC) were also tested for B19V contamination. In addition, B19V genome prevalence in minipools(including 90 individual donations) of 49680 individual plasma samples collected between August 2011 and March 2012 by a single Chinese manufacturer was investigated. IgM/IgG was also investigated in plasma pools/derivatives and in minipools with B19V-DNA titers above 1x10⁴ and 1x10⁶ geq/mL using B19 ELISA IgM/IgG assay(Virion-Serion, Würzburg, Germany), respectively.

Results

B19V-DNA was detected in 54.2% of plasma pools from two Chinese blood product manufacturers; among recently produced blood products, B19V was detected in 21/54 IVIG samples, 19/35 factor VIII samples, 6/7 fibrinogen samples, and 12/17 PCC samples, but not in albumin samples. The levels of B19V-DNA in these samples varied from 10²-10⁷ geq/mL. In samples with >10⁴ geq/mL genome DNA, B19V-specific IgG was also found in all corresponding plasma pools and IVIG, whereas none was detected in the majority of other plasma derivatives. Screening of plasma donations indicated that most minipools were contaminated with B19V-DNA (10²-10⁸ geq/mL) and one donation had 1.09 × 10¹⁰ geq/mL B19V genomic DNA along with a non-classical IgG/IgM profile.

Conclusions

Despite the implementation of some inactivation/removal methods designed to prevent viral contamination, B19V DNA was detectable in Chinese plasma pools and plasma derivatives. Thus, the introduction of B19V screening and discard donation with high viramic concentration for Chinese plasma donors would be desirable.

Multicenter evaluation of a commercial multiplex polymerase chain reaction test for screening plasma donations for parvovirus B19 DNA and hepatitis A virus RNA

BACKGROUND

Three European laboratories evaluated the TaqScreen DPX test (DPX test), a multiplex nucleic acid test assay for the simultaneous detection and quantitation of parvovirus B19 (B19V) DNA and the detection of hepatitis A virus (HAV) RNA.

STUDY DESIGN AND METHODS

The 95% limit of detection of the test for B19V and HAV was determined using the respective WHO International Standards. The reproducibility of the test was evaluated by testing replicate samples of B19V at log 4.0 and 40 IU/mL and HAV at 5 IU/mL. The accuracy of the DPX test for B19V was evaluated by replicate testing of B19V samples containing log 3.0, log 4.0, and log 5.0 IU/mL. Panels of B19V Genotypes 1, 2, and 3 and HAV genotypes were evaluated. Cross-contamination was evaluated. For comparison of the DPX test and the established tests, the sites tested plasma samples in pools of either 96 or 480 donations.

RESULTS

The mean 95% lower limits of detection of the three laboratories for B19V and HAV were 20.30 and 1.85 IU/mL. The test showed good reproducibility with the major part of the variance of the test being attributed to intermediate assay variation. The test showed great accuracy for B19V, especially at log 4.0 IU/mL. Spiking of test pools of 480 donations and manufacturing pools with log 4.0 IU/mL B19 DNA and 4 IU/mL HAV RNA showed that the DPX assay was robust. The test was able to detect the three genotypes of B19V and HAV genotypes. No cross-contamination was seen. Test results of routine samples correlated well with those of the established tests.

CONCLUSION

The DPX test is a robust and sensitive test for the detection of B19V and HAV in plasma samples. The quantitative B19V results obtained with the test are accurate, and the test is able to detect all the known genotypes of B19V and HAV and fulfills all the European Pharmacopoeia and Food and Drug Administration requirements for a B19V and HAV test for screening of plasma donations and samples from plasma pools for manufacture.

Alternative blood products and clinical needs in transfusion medicine

The primary focus of national blood programs is the provision of a safe and adequate blood supply. This goal is dependent on regular voluntary donations and a regulatory infrastructure that establishes and enforces standards for blood safety. Progress in ex vivo expansion of blood cells from cell sources including peripheral blood, cord blood, induced pluripotent stem cells, and human embryonic stem cell lines will likely make alternative transfusion products available for clinical use in the near future. Initially, alloimmunized patients and individuals with rare blood types are most likely to benefit from alternative products. However, in developed nations voluntary blood donations are projected to be inadequate in the future as blood usage by individuals 60 years and older increases. In developing nations economic and political challenges may impede progress in attaining self-sufficiency. Under these circumstances, ex vivo generated red cells may be needed to supplement the general blood supply.

Serological study on parvovirus B19 infection in multitransfused thalassemia major patients and its transmission through donor units

Background:

Human parvovirus B19 (B19) virus is a newly recognized agent for transfusion transmitted diseases. Beta-thalassemia major patients receive a hypertransfusion regimen, hence, are prone to acquire B19 infection; moreover, B19 escapes viral inactivation methods and donor units are not tested for B19, but there are just a couple of studies globally and none from the Asian continent. Hence, a study was designed to find the frequency of B19 infection and its transmission in multitransfused thalassemia patients.

Materials and Methods:

Ninety multitransfused beta-thalassemia major (thalassemia) patients, 32 controls (age, sex matched) without any history of transfusion were enrolled. Besides the donor units were tested in B19 un-infected patients. B19 specific IgG and IgM antibodies in the sera were analyzed by ELISA (in-house), using B19 VPI and VP2 recombinant and purified antigens; additionally HBsAg and anti-HIV and anti-HCV antibodies were tested for coexisting infections.

Results:

Seventy-three (81%) thalassemia patients tested positive for anti-B19 IgG antibodies as compared to seven (21%) in the controls group (P < 0.01), while anti-B19 IgM antibodies were detected in 37 (41.1%) compared to two (6.2%) in the controls (P < 0.01). Mean age of the thalassemia patient was eight years (range 2 – 18 years) and B19 infection was highest in the six-to-ten year range. Seropositivity increased with the number of transfusions. Two of the four HBsAg positive and five of the seven anti-HCV IgM antibody-positive patients also had anti-B19 IgM. After a six-month follow-up, four (25%) of the 16 seronegative patients seroconverted and anti-B19 IgM antibodies were detected in their donor units.

Conclusions:

Most of multitransfused thalassemics were B19 seropositive or had anti-B19 IgM; in the remaining uninfected group, B19 got transmitted through infected / IgM-positive donor units.