Phylogenetic analysis of human parvovirus b19 sequences from eleven different countries confirms the predominance of genotype 1 and suggests the spread of genotype 3b

Parvovirus B19 remains an underestimated pathogen among infections during gestation in Argentina: Insights through the study of symptomatic and asymptomatic pregnant patients and newborns from Córdoba

BACKGROUND

Parvovirus B19 (B19 V) infection during pregnancy can cause adverse fetal outcomes. Our aim was to characterize both clinical and asymptomatic maternal and neonatal cases by studying virological and serological markers of B19 V infection, and to sequence the complete genome of the circulating virus in Argentina.

METHODS

Symptomatic patients were included based on maternal and/or fetal-neonatal signs attributable to B19 V infection during gestation. Pregnant patients were analyzed in either the timely diagnosis group (TD, samples obtained when symptoms were present and infection was suspected) or the retrospective diagnosis group (RD, samples collected immediately postpartum), and newborns were analyzed at birth. A sample of asymptomatic individuals was also analyzed. Diagnostic tests (PCR/qPCR/serology) and sequencing were performed on archived serum samples from 2018 to 2023, and clinical data were obtained from medical records.

RESULTS

We studied 328 symptomatic patients, including 185 pregnant patients (73 TD and 112 RD) and 143 newborns. Among them, we identified 27/328 (8.2 %) positive cases (B19V+): 12/73 (16.4 %) in the TD group, 6/112 (5.4 %) in the RD group, and 9/143 (6.3 %) newborns. Within the 77 mother-newborn pairs included, there were 8 (10.4 %) B19 V infections and 6 cases of vertical transmission. Additionally, B19 V infection was detected in 26/310 (8.4 %) asymptomatic patients. Phylogenetic analysis identified genotype 1a as a circulating strain in Argentina.

CONCLUSIONS

Our findings highlight the need to raise awareness and enhance diagnostic approaches in Argentina to more effectively identify and manage B19 V infections during pregnancy in our region.

Reassessing the Risk of Severe Parvovirus B19 Infection in the Immunocompetent Population: A Call for Vigilance in the Wake of Resurgence

Despite Parvovirus B19 (B19V) generally causing mild or asymptomatic infections, and only certain high-risk groups such as hematological or immunocompromised patients and pregnant women tending to develop complications, several factors challenge the assumption of a "benign" clinical course in immunocompetent adults and adolescents. A significant proportion of the population may harbor undiagnosed health conditions or genetic predispositions that could render them more susceptible to severe B19V complications. These could include mild hematological disorders, immune dysregulation not resulting in overt immunodeficiency, or underlying cardiac conditions. Concurrent infections with other pathogens, even seemingly minor ones, could synergistically increase the severity of B19V infection, leading to more pronounced clinical manifestations. While not definitively proven, the possibility of emerging B19V strains with increased virulence or altered tissue tropism cannot be entirely discounted. Additionally, the period of pandemic-related restrictions likely led to reduced B19V circulation, potentially resulting in a cohort of young adults with limited natural immunity, making them more vulnerable to infection. Potential clinical consequences include atypical and severe presentations, even in individuals without known risk factors. The traditional focus on B19V primarily as a pediatric concern might lead to underdiagnosis or delayed diagnosis in adults, potentially hindering timely intervention and management. A surge in B19V-related complications, even if individually mild, could collectively strain healthcare resources, particularly in settings with limited capacity or pre-existing pressures. Possible recommendations are to heighten clinical awareness with a high index of suspicion for B19V infection in adults and adolescents presenting with compatible symptoms, even in the absence of classic risk factors. Additionally, expanding testing criteria and enhancing public health surveillance efforts would be prudent.

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.

Changing epidemiology of parvovirus B19 in the Netherlands since 1990, including its re-emergence after the COVID-19 pandemic

Parvovirus B19V (B19V) infection during pregnancy can be complicated by potentially life-threatening fetal hydrops, which can be managed by intrauterine transfusion (IUT). This study investigates the long-term temporal patterns in the epidemiology of B19V and evaluates the impact on fetal hydrops, by combining data on B19V infections from the Dutch Sentinel Surveillance system in the period 1990 to 2023, Dutch blood banking data and hospital data on fetal hydrops. Using wavelet analysis, we identified annual epidemic cycles in the Netherlands in the period 1990-2019 and we identified superimposed multiannual cycles in the period 1990-2009. After 2009, no multiannual cycle could be identified, although the incidence fluctuated and correlates with number of IUT performed. As of 2020, weekly reports of B19V infection demonstrated a historically low incidence and B19V-DNA positive blood donors were nearly absent. From May 2020 to May 2023, no IUT for B19V-related hydrops was performed. In the spring of 2023, B19V infections re-emerged, reaching pre-pandemic epidemic levels. Due to the changes in B19V epidemiology over the last 30 years and the near-absence of B19V during the COVID-19 pandemic, the resulting low immunity levels may lead to rebound outbreaks. Alertness to severe complications such as fetal hydrops is warranted.

A Glimpse into the Past: What Ancient Viral Genomes Reveal About Human History

Humans have battled viruses for millennia. However, directly linking the symptomatology of disease outbreaks to specific viral pathogens was not possible until the twentieth century. With the advent of the genomic era and the development of advanced protocols for isolation, sequencing, and analysis of ancient nucleic acids from diverse human remains, the identification and characterization of ancient viruses became feasible. Recent studies have provided invaluable information about past epidemics and made it possible to examine assumptions and inferences on the origin and evolution of certain viral families. In parallel, the study of ancient viruses also uncovered their importance in the evolution of the human lineage and their key roles in shaping major events in human history. In this review, we describe the strategies used for the study of ancient viruses, along with their limitations, and provide a detailed account of what past viral infections have revealed about human history.

Vasconcelos D, Côrtes MF, Costa SF, Mendoza TRT, Gomes HR, Witkin SS, Mendes-Correa MC. Encephalopathy Caused by Human Parvovirus B19 Genotype 1 Associated with Haemophilus influenzae Meningitis in a Newborn

Parvovirus B19 infection is associated with a wide range of clinical manifestations, from asymptomatic to severe neurological disorders. Its major clinical symptoms, fever and rash, are common to multiple viruses, and laboratory tests to detect B19 are frequently not available. Thus, the impact of B19 on public health remains unclear. We report the case of a 38-day old girl admitted to São Paulo Clinical Hospital, Brazil, with an initial diagnosis of bacterial meningitis, seizures, and acute hydrocephalus. Antibiotic therapy was maintained for one week after admission and discontinued after negative laboratory results were obtained. Nine days after symptoms onset, a cerebral spinal fluid (CSF) sample revealed persistent pleocytosis. The complete B19 complete genome was subsequently identified in her CSF by a metagenomic next-generation sequencing approach. This report highlights the possible involvement of B19 in the occurrence of acute neurological manifestations and emphasizes that its possible involvement might be better revealed by the use of metagenomic technology to detect viral agents in clinical situations of unknown or uncertain etiology.

Clinical Presentation of Parvovirus B19 Infection in Adults Living with HIV/AIDS: A Case Series

Parvovirus B19 (B19V) infection varies clinically depending on the host's immune status. Due to red blood cell precursors tropism, B19V can cause chronic anemia and transient aplastic crisis in patients with immunosuppression or chronic hemolysis. We report three rare cases of Brazilian adults living with human immunodeficiency virus (HIV) with B19V infection. All cases presented severe anemia and required red blood cell transfusions. The first patient had low CD4⁺ counts and was treated with intravenous immunoglobulin (IVIG). As he remained poorly adherent to antiretroviral therapy (ART), B19V detection persisted. The second patient had sudden pancytopenia despite being on ART with an undetectable HIV viral load. He had historically low CD4⁺ counts, fully responded to IVIG, and had undiagnosed hereditary spherocytosis. The third individual was recently diagnosed with HIV and tuberculosis (TB). One month after ART initiation, he was hospitalized with anemia aggravation and cholestatic hepatitis. An analysis of his serum revealed B19V DNA and anti-B19V IgG, corroborating bone marrow findings and a persistent B19V infection. The symptoms resolved and B19V became undetectable. In all cases, real time PCR was essential for diagnosing B19V. Our findings showed that adherence to ART was crucial to B19V clearance in HIV-patients and highlighted the importance of the early recognition of B19V disease in unexplained cytopenias.

Cutavirus on the skin in an Asian cohort: identification of a novel geographically related genotype

BACKGROUND

Cutavirus (CuV) is the newest human parvovirus and is currently receiving increasing attention because of its possible association with cutaneous T-cell lymphoma. Despite the pathogenetic potential of CuV, it has been detected in normal skin; however, little is known about the prevalence, infection levels, and genetic variations of this virus in the skin of the general population.

METHODS

We investigated the CuV DNA prevalence and viral loads concerning age, sampling location, and gender using 678 skin swabs collected from the normal-appearing skins of 339 Japanese participants aged 2-99 years. Phylogenetic analyses were also conducted based on the near-full-length CuV sequences identified in this study.

RESULTS

Both the CuV DNA prevalence and viral loads were significantly higher in the skin of elderly persons aged ≥60 years compared with those of persons aged < 60 years. CuV DNA tended to persist in the skin of elderly individuals. No significant difference in viral loads was observed between the skin of the upper arm and the skin of the forehead in CuV DNA-positive specimens. Significantly higher viral loads were evident in men vs. women, although no gender-associated differences in viral prevalence were noted. Phylogenetic analyses demonstrated the existence of Japanese-specific viruses that were genetically distinct from viruses prevalent in other areas, especially Europe.

CONCLUSIONS

This large study suggests that high levels of CuV DNA are prevalent on the skin of elderly adults. Our findings also indicated the prevalence of geographically related CuV genotypes. A follow-up study of this cohort should provide helpful information on whether CuV may become pathogenic.

Next Generation Sequencing for the Analysis of Parvovirus B19 Genomic Diversity

Parvovirus B19 (B19V) is a ssDNA human virus, responsible for an ample range of clinical manifestations. Sequencing of B19V DNA from clinical samples is frequently reported in the literature to assign genotype (genotypes 1-3) and for finer molecular epidemiological tracing. The increasing availability of Next Generation Sequencing (NGS) with its depth of coverage potentially yields information on intrinsic sequence heterogeneity; however, integration of this information in analysis of sequence variation is not routinely obtained. The present work investigated genomic sequence heterogeneity within and between B19V isolates by application of NGS techniques, and by the development of a novel dedicated bioinformatic tool and analysis pipeline, yielding information on two newly defined parameters. The first, α-diversity, is a measure of the amount and distribution of position-specific, normalised Shannon Entropy, as a measure of intra-sample sequence heterogeneity. The second, σ-diversity, is a measure of the amount of inter-sample sequence heterogeneity, also incorporating information on α-diversity. Based on these indexes, further cluster analysis can be performed. A set of 24 high-titre viraemic samples was investigated. Of these, 23 samples were genotype 1 and one sample was genotype 2. Genotype 1 isolates showed low α-diversity values, with only a few samples showing distinct position-specific polymorphisms; a few genetically related clusters emerged when analysing inter-sample distances, correlated to the year of isolation; the single genotype 2 isolate showed the highest α-diversity, even if not presenting polymorphisms, and was an evident outlier when analysing inter-sample distance. In conclusion, NGS analysis and the bioinformatic tool and pipeline developed and used in the present work can be considered effective tools for investigating sequence diversity, an observable parameter that can be incorporated into the quasispecies theory framework to yield a better insight into viral evolution dynamics.

Ancient viral genomes reveal introduction of human pathogenic viruses into Mexico during the transatlantic slave trade

After the European colonization of the Americas, there was a dramatic population collapse of the Indigenous inhabitants caused in part by the introduction of new pathogens. Although there is much speculation on the etiology of the Colonial epidemics, direct evidence for the presence of specific viruses during the Colonial era is lacking. To uncover the diversity of viral pathogens during this period, we designed an enrichment assay targeting ancient DNA (aDNA) from viruses of clinical importance and applied it to DNA extracts from individuals found in a Colonial hospital and a Colonial chapel (16th-18th century) where records suggest that victims of epidemics were buried during important outbreaks in Mexico City. This allowed us to reconstruct three ancient human parvovirus B19 genomes and one ancient human hepatitis B virus genome from distinct individuals. The viral genomes are similar to African strains, consistent with the inferred morphological and genetic African ancestry of the hosts as well as with the isotopic analysis of the human remains, suggesting an origin on the African continent. This study provides direct molecular evidence of ancient viruses being transported to the Americas during the transatlantic slave trade and their subsequent introduction to New Spain. Altogether, our observations enrich the discussion about the etiology of infectious diseases during the Colonial period in Mexico.

Molecular-genetic characterization of human parvovirus B19 prevalent in Kerala State, India

Background

Human parvovirus B19V is a DNA virus, and a member of the family Parvoviridae, that causes various clinical manifestations, from asymptomatic to persistent infection that is associated with different autoimmune diseases. The parvovirus B19 evolves with a very high mutation rate that is closer to those of existing RNA viruses. Globally circulating B19V is currently classified into three genotypes, but their distribution is not spatially and temporally correlated. Except for a few recent reports on B19V entry into the human host and its genetic diversity, there is a lack of sufficient studies on this virus from distinct geographical locations and no clear understanding of its evolution has been documented.

Methods

To better understand the evolution of the Human parvo B19V virus from India's southern part, a geographically distinct location with no reports of B19V genomes, we have screened for B19V in 456 suspected cases using VP1/2 surface marker genes, and its characteristics were studied in detail. Amongst 456 clinically suspected B19V samples, 7.2% (33/456) were found positive by nested PCR (nPCR) were subsequently validated by real-time PCR, Sanger sequencing, and metagenome analysis.

Results

Human parvovirus B19 infection was shown among 33 of 456 patients when tested by nPCR; 30 among these were also positive by qPCR and were subsequently confirmed by sequencing 75% nPCR positive samples and 76% qPCR positive samples were from patients with age. ≥ 50 years respectively (Additional file 1: Table S1). The complete VP1/2 gene assembly from the South Indian strain showed three novel mutations (T122A, V128I, I283V), which might significantly impact the stability and virulence of the B19V virus circulating in this part of the world. These mutations might be crucial for its adaptive evolutionary strategies facilitating the spread and infectivity potential of the virus. In maximum likelihood phylogeny of VP1/2 sequences, the South Indian B19V strain forms a separate clade closer to the existing genotype two strains circulating worldwide.

Conclusion

Our study contributes to a better understanding of the human parvovirus's genetic and evolutionary characteristics in South India. Also, it highlights the possibility that a positive selection pressure acting on VP1/2 could increase the survival and replication capabilities of the viruses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01569-1.

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.

Identification of human parvovirus 4 genotypes 1 and 2 in Chinese source plasma pools

Human parvovirus B19 (B19V) and human parvovirus 4 (PARV4) are known to infect humans and transmit through contaminated blood and blood products. Globally, three genotypes of B19V, as well as PARV4, have been identified, respectively. The existence of different B19V genotypes in Chinese plasma donors has been investigated, however, the data regarding PARV4 were not available. The main objective of this study is to identify the genotypes of PARV4 circulating in Chinese plasma donors. By using a duplex quantitative polymerase chain reaction assay adapted for all genotypes of B19V and PARV4, 78 source plasma pools for fractionation were screened and quantified. Results showed that positive rates of B19V and PARV4 DNA in plasma pool samples were 25.64% and 14.10%, respectively. PARV4 sequences in two positive samples were next genotyped, and these two sequences belonged to PARV4 genotypes 1 and 2, respectively. In conclusion, the data present demonstrate the existence of PARV4 genotypes 1 and 2 in Chinese plasma donors for the first time and also show the relatively lower prevalence and level of PARV4 DNA in Chinese plasma donors in comparison with that of B19V DNA.

At least two PARV4 genotypes, 1 and 2, were currently present in China.

The prevalence and level of PARV4 DNA in Chinese plasma donors were relatively lower in comparison with that of B19V DNA.

The rate of B19V and PARV4 coinfection in Chinese source plasma pools was low.

Comprehensive surveillance data suggest a prominent role of parvovirus B19 infection in Belarus and the presence of a third subtype within subgenotype 1a

Human parvovirus B19 (B19V) infection is not notifiable in Belarus and its most common clinical presentation erythema infectiosum (EI) is often difficult to distinguish from other exanthematous diseases. The objective of this study was to provide comprehensive data about EI epidemiology in Belarus based on the serological and molecular investigation of samples from measles and rubella discarded cases collected between 2005 and 2019. Overall, 4919 sera were investigated for IgM antibodies against B19V and the positive cases were analysed according to year, season and age. B19V DNA was amplified by PCR in a total of 238 sera from all over the country, and sequenced for phylogenetic analyses. B19V infection was confirmed in 1377 (27.8%) measles and rubella discarded cases. Two high incidence periods and a seasonal increase of EI between mid-February to mid-July were identified. Children from 4 to 6 and from 7 to 10 years of age represented the largest groups of patients (22.51% and 22.66% of all cases, respectively), followed by adults between 20 and 29 years of age (14.23%). Among the 238 B19Vs sequenced, one belonged to subgenotype 3b and 237 to subgenotype 1a with 81 (34.2%) clustering with subtypes 1a1 and 153 (64.6%) with 1a2. Three strains (1.2%) formed an additional, well-supported cluster suggesting the presence of another subtype of 1a, tentatively named 1a3. The epidemiological and molecular analyses highlighted not only the prominent role of B19V in exanthematous diseases in Belarus, but also suggested a previously underestimated diversity of subgenotype 1a sequences with a third subtype 1a3.

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.

Parvovirus B19 DNA detection in treatment-naïve HIV anemic patients in Lagos, Nigeria: a case control study

BACKGROUND

Parvovirus B19 (B19) has tropism for cells of the erythroid lineage, which may lead to transient inhibition of erythropoiesis. Several studies and case reports suggested that B19 infection may contribute significantly to severe chronic anemia in HIV infected persons.

OBJECTIVE

To detect parvovirus B19 DNA in treatment-naïve HIV patients.

METHODS

This was a case control retrospective study. One hundred nineteen anemic and 81 non-anemic treatment-naïve HIV infected patients participated in the study at the Lagos University Teaching Hospital, Lagos, Nigeria. Polymerase chain reaction was used to detect B19 DNA.

RESULTS

Out of 200 patients analysed, 13(6.5%) had parvovirus B19 DNA. Eight HIV patients with anemia had B19 DNA while five non-anemic HIV patients had B19 DNA. This suggests that the presence of B19 DNA in the blood of HIV positive individuals may contribute to anemia because the majority (61.5%) who were positive for B19 DNA had anemia as compared to the non-anemic control group (38.5%).

CONCLUSION

This study shows that the presence of B19 DNA in anemic HIV infected patients is not associated with chronic anaemia in HIV infection because no significant association exist.

Optimized nested PCR enhances biological diagnosis and phylogenetic analysis of human parvovirus B19 infections

Diagnosis and epidemiological analysis of human parvovirus B19 (hB19V) infections are essential for disease management in severely ill patients. This study aimed to evaluate the performance of an optimized NS1-VP1u nested PCR for detection and sequencing of viruses in clinical samples using 224 clinical and five reference samples. PCR sensitivity, specificity, and positive and negative predictive values were perfect (100%). While phylogenetic analysis of a 615 bp-long fragment demonstrated that the viruses in all of the samples belonged to genotype 1, this study confirmed that this optimized PCR could detect all known hB19V with high performance.

Identification of human parvovirus B19 among measles and rubella suspected patients from Cuba

Between September 2014 and December 2015, 298 sera from rash and fever patients from all over Cuba were investigated for specific IgM antibodies against measles, rubella, dengue, human parvovirus B19 (B19V) and human herpesvirus 6 (HHV6) using a commercial enzyme-linked immunosorbent assay kits. B19V IgM positive and equivocal samples were investigated by a polymerase chain reaction and genotyping. No measles, rubella or dengue cases were detected. HHV6-IgM antibodies were confirmed in 5.7% and B19V-IgM antibodies in 10.7% of the patients. A total of 31.3% of the B19V cases were between 5 and 9 years old and 34.4% were 20 years and older. The only B19V sequence obtained belonged to genotype 1a. Diagnosis was established for only 16% of the rash and fever patients, suggesting that other diseases such as Zika or Chikungunya may play a role.

Genetic diversity of primate erythroparvovirus 1 between 2009 and 2016: First report from Turkey

Parvovirus B19 (B19V) is one of the major viral pathogens that infect only human beings. This study's aim is to determine which genotypes of the B19V are present in Turkey and to perform a phylogenetic analysis. Twelve B19V positive serum specimens already diagnosed by real-time PCR amplifying a partial region of the NS gene were included in this study. The serological markers and viral loads of the patients were determined. The positivity of the specimens was confirmed using semi-nested PCR. To determine the genotype of the B19V, PCR-positive amplicons were sequenced directly and compared to GenBank-referenced strain sequences. The phylogeny of the 12 sequenced strains was constructed with the maximum likelihood method. Two different genotypes of B19V were identified in our study. Genotype 2 of B19V was not detected. All of the B19V genotype 1 sequences were clustered in the common genotype 1a cluster (10/12, 83.3%). The average quantification of the B19V strains was determined to be 2.1 × 10⁷ IU/ml. The nucleotide identities between our strains and those isolated in other countries were 85.8%-99.5%. Compared to the Turkish strains identified in our study, at the nucleotide level, the closest strains based on genotypes 3b and 1a were the Germany and Netherlands isolates respectively. This study was the first to provide the genotypic variation of B19V circulated in Turkey. We determined two distinct subtypes of B19V, including subtype 3b and 1a. While the genotype 1 is common all over the world, genotype 3 has begun to spread outside of Africa.

Ancient human parvovirus B19 in Eurasia reveals its long-term association with humans

Human parvovirus B19 (B19V) is a ubiquitous human pathogen associated with a number of conditions, such as fifth disease in children and arthritis and arthralgias in adults. B19V is thought to evolve exceptionally rapidly among DNA viruses, with substitution rates previously estimated to be closer to those typical of RNA viruses. On the basis of genetic sequences up to ∼70 years of age, the most recent common ancestor of all B19V has been dated to the early 1800s, and it has been suggested that genotype 1, the most common B19V genotype, only started circulating in the 1960s. Here we present 10 genomes (63.9-99.7% genome coverage) of B19V from dental and skeletal remains of individuals who lived in Eurasia and Greenland from ∼0.5 to ∼6.9 thousand years ago (kya). In a phylogenetic analysis, five of the ancient B19V sequences fall within or basal to the modern genotype 1, and five fall basal to genotype 2, showing a long-term association of B19V with humans. The most recent common ancestor of all B19V is placed ∼12.6 kya, and we find a substitution rate that is an order of magnitude lower than inferred previously. Further, we are able to date the recombination event between genotypes 1 and 3 that formed genotype 2 to ∼5.0-6.8 kya. This study emphasizes the importance of ancient viral sequences for our understanding of virus evolution and phylogenetics.

Prevalence and Genotypes of Parvovirus B19 Among HIV Positive Children in Ibadan, Oyo State, Nigeria

Human Parvovirus B19 (B19V) is a global infection with over 50% of infected children residing in sub-Saharan Africa. It causes persistent anaemia under immuno-compromised states such as HIV infection, thereby complicating the course of HIV infection. This study was therefore designed to determine the prevalence and genotypes of B19V among HIV positive children. Blood specimens were collected from HIV positive children and genomic DNA extracted and assayed for the presence of Parvovirus B19 DNA using polymerase chain reaction and the product detected by gel electrophoresis. Amplicons for positive PCR were purified and sequenced for genotype analysis. For the purpose of comparison (differences in the sequences of the NS1/VP1u region), nine HIV negative children were enrolled in this study. Two (1.3%) of the 158 HIV infected children were positive for Parvovirus B19 DNA. Analysis of the results showed a low prevalence of Parvovirus B19 among HIV positive children but a significant relationship was established between Parvovirus B19 infection and the severity of anaemia (p=0.015). Phylogenetic analysis of the sequence data showed that all the B19 virus isolates detected in this study were genotype 1. This study therefore has been able to give an insight to the prevalence and circulating genotypes of Parvovirus B19 among HIV infected children and also establishing a relationship between anaemia and parvovirus B19 infection.

Detection of human parvovirus B19 in serum samples from children under 5 years of age with rash-fever illnesses in the Democratic Republic of the Congo

BACKGROUND

It has been demonstrated that infection with human parvovirus B19 (B19V) is associated with rash-fever illnesses. The present study aimed to investigate B19V as an aetiological agent of rash-fever syndromes in Congolese children confirmed as measles and rubella IgM-negative. An ELISA IgM test and PCR were performed to screen for B19V.

METHODS

A total of 177 archived serum samples were randomly selected from the measles biobank of the National Institute for Biomedical Research (INRB). Samples were investigated for anti-B19V IgM and B19V DNA. These samples originated from children <5years of age with measles-like rashes, previously confirmed as negative for both measles and rubella IgM.

RESULTS

Out of 177 serum samples tested by ELISA and 168 tested by PCR, 109 were positive for B19V IgM antibodies (61.6%) and 87 (51.8%) were positive for B19V DNA. Positive samples in both assays were from all provinces of DRC.

CONCLUSIONS

B19V plays a role in rash-fever illnesses in children under 5 years of age suspected of having measles or rubella infections in DRC. As an aetiological cause of rash and fever syndromes, the present study demonstrates that B19V should also be considered during the laboratory investigation of rash-fever illnesses in DRC, particularly in the paediatric population. There is a need to conduct further studies in order to gain a better understanding of the spatiotemporal pattern of B19V and to define the genotype(s) of B19V circulating in DRC.

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.

Serological and molecular analysis of parvovirus B19 infection in Mayan women with systemic lupus erythematosus in Mexico

Background:

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that mainly affects women, characterized by the production of autoantibodies. Its causal agent is unknown, but the combination of environmental, hormonal and genetic factors may favor the development of the disease. Parvovirus B19 has been associated with the development of SLE, since it induces the production of anti-single stranded DNA antibodies. It is unknown whether PV-B19 infection is an environmental factor that trigger or reactivate SLE in the Mexican Mayan population.

Aim:

A preliminary serological and molecular study of PV-B19 infection in Mayan women with established SLE was done.

Methods:

IgG and IgM anti PV-B19 were evaluated in 66 SLE patients and 66 control subjects, all women of Mayan origin. Viral DNA and viral load were analyzed by qPCR.

Results:

Insignificant levels of IgM were observed in 14.3% (4/28) of the patients and 11.4% (4/35) of control subjects. IgG was detected in 82.1% (23/28) of the patients and 82.9% (29/35) of control subjects, but were significantly higher in patients. Viral DNA was found in 86.0% (57/66) of the patients and 81.0% (54/66) of control subjects. Viral load, quantified in 28/66 patients and 31/66 controls which were positive for IgM and IgG, was significantly higher in controls.

Conclusion:

The high prevalence of PV-B19 in Yucatan, and the presence of IgM, IgG, and viral load in Mayan women with established SLE suggest that PV-B19 infection could be an environmental factor to trigger or reactivate SLE.

Simultaneous detection and differentiation of human parvovirus B19 and human parvovirus 4 by an internally controlled multiplex quantitative real-time PCR

Human parvovirus B19 (B19V) and human parvovirus 4 (PARV4) are two parvoviruses known to infect humans and transmit through blood and plasma derived medicinal products (PDMPs). Inactivation of the two parvoviruses has proven to be difficult and nucleic acid testing (NAT) would be an efficient means to exclude viruses. In this study, an internally controlled multiplex quantitative real-time PCR (qPCR) assay for B19V and PARV4 simultaneous detection and quantification was established and evaluated. The optimized multiplex qPCR assay allowed for simultaneous detection of all of the genotypes (1-3) of B19V and PARV4, with equal limit of quantification (LOQ) of 5 copies/μL, rather than other blood-borne viruses. It had a wide dynamic range of reliable amplification linearity of at least 8 orders of magnitude. Low standard deviations (SD) of quantification cycle (Cq) values and low coefficients of variation (CV) of copy numbers for both B19V and PARV4 suggested a high level of repeatability and reproducibility for the multiplex qPCR assay. This multiplex qPCR assay can be served as a readily applicable approach to screen plasma units intended for further manufacturing into PDMPs to reduce the risk of parvoviruses infection by such products and may also be useful for the detection of B19V/PARV4 co-infection or co-existence.

Impact of Parvovirus B19 Viremia in Liver Transplanted Children on Anemia: A Retrospective Study

Acute parvovirus B19 (B19V) infection in immunocompromised patients may lead to severe anemia. However, in adult transplant recipients, B19V reactivations without anemia and low-level viremia are common. The impact of B19V in pediatric transplant patients, with high risk of primary infection, is investigated here. In a six-month period, 159 blood samples of 54 pediatric liver transplant recipients were tested for B19V DNA by quantitative real-time PCR. Viremia was correlated with anemia and immunosuppression and compared with rates in adult transplant recipients. B19V DNA was detected in 5/54 patients. Primary B19V infections were observed in four patients prior to and in one patient after transplantation. Rates of viremia were significantly higher in pediatric recipients than in adults. Prolonged virus shedding after primary infection prior to transplantation accounts for most viremic cases. Anemia was significantly more frequent in samples from viremic patients, but remained mild. In 15% of anemic samples, B19V DNA was detected. Therefore, in anemic pediatric transplant recipients, diagnostics for B19V seem reasonable.

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.

Existence of various human parvovirus B19 genotypes in Chinese plasma pools: genotype 1, genotype 3, putative intergenotypic recombinant variants and new genotypes

Background

Human parvovirus B19 (B19V) is a frequent contaminant of blood and plasma-derived medicinal products. Three distinct genotypes of B19V have been identified. The distribution of the three B19V genotypes has been investigated in various regions or countries. However, in China, data on the existence of different B19V genotypes are limited.

Methods

One hundred and eighteen B19V-DNA positive source plasma pool samples collected from three Chinese blood products manufacturers were analyzed. The subgenomic NS1/VP1u region junction of B19V was amplified by nested PCR. These amplified products were then cloned and subsequently sequenced. For genotyping, their phylogenetic inferences were constructed based on the NS1/VP1-unique region. Then putative recombination events were analyzed and identified.

Results

Phylogenetic analysis of 118 B19V sequences attributed 61.86 % to genotype 1a, 10.17 % to genotype 1b, and 17.80 % to genotype 3b. All the genotype 3b sequences obtained in this study grouped as a specific, closely related cluster with B19V strain D91.1. Four 1a/3b recombinants and 5 new atypical B19V variants with no recombination events were identified.

Conclusions

There were at least 3 subtypes (1a, 1b and 3b) of B19V circulating in China. Furthermore, putative B19V 1a/3b recombinants and unclassified strains were identified as well. Such recombinant and unclassified strains may contribute to the genetic diversity of B19V and consequently complicate the B19V infection diagnosis and NAT screening. Further studies will be required to elucidate the biological significance of the recombinant and unclassified strains.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-016-0611-6) contains supplementary material, which is available to authorized users.

Insights into epidemiology of human parvovirus B19 and detection of an unusual genotype 2 variant, Bulgaria, 2004 to 2013

The present study aimed to determine the role of human parvovirus В19 (B19V) as an aetiological agent in measles and rubella negative fever/rash patients from Bulgaria between 2004 and 2013. A total of 1,266 sera from all over the country were tested for B19V IgM antibodies and all positives were further investigated by polymerase chain reaction (PCR). Overall, 280 sera (22%) were B19V IgM positive and 227 of these (81%) were also PCR positive. The highest number of IgM positives was found among five to nine year-old children (27%). Eight infected women gave birth to healthy children; one fetus was aborted with hydrops fetalis. Of the 55 genetic sequences obtained, 54 belonged to genotype 1a and one grouped as a genotype 2 outlier. Phylogenetic analysis of all available genotype 2 sequences covering the 994 nucleotide non-structural protein 1(NS1)/capsid viral protein 1 (VP1) unique region junction, showed that only one other sequence grouped with the outlier strain, forming a clearly distinct and well-supported cluster of genotype 2 (between-group genetic distance: 3.32%). In accordance with B19V nomenclature, this cluster may represent a new subgenotype 2b. The study showed that B19V infections may be falsely identified as rubella or measles in ca 22% of cases, emphasising the need for laboratory confirmation.

Genotype 3b of human parvovirus B19 detected from hospitalized children with solid malignancies in a North Indian tertiary care hospital

Human parvovirus B19 (B19V) infection is known to cause serious consequences in immuno-compromized individuals. The present cross sectional study was designed to estimate the prevalence and genotype distribution of B19V in children receiving chemotherapy for solid malignancies at a tertiary care hospital in North India during October 2013 to May 2015. Serum samples from all the patients were tested for anti-B19V IgM and IgG antibodies and for B19V-DNA as soon as received. Samples testing positive for B19V-DNA were subjected to viral load estimation and to genotype determination by sequencing. Total 96 children were enrolled of which 9 (9.3%), 32 (33.3%), and 25 (26%) tested positive for anti-B19V IgM, anti-B19V IgG, and B19V-DNA, respectively. The viral load of B19V-DNA positive children ranged from 5.5 × 10(2) to 3.5 × 10(12) copies/ml. Accordingly children were divided into three groups: group I, with acute infection (n = 25); group II, previously exposed (n = 27), and group III, negative for B19V infection or with inappropriate antibody response (n = 44). B19V positivity was significantly associated (P-value < 0.0001) with a history of blood transfusion in the past 6 months, severe anemia (hemoglobin levels <6 gm%) and thrombocytopenia (platelets <150,000/cu.mm.). Sequence analysis of 21 of 25 DNA positive samples showed that all of them were Genotype 3b that clustered into three groups. All the sequences within each cluster were identical. The nucleotide identity of the sequences suggests a nosocomial outbreak of B19V during the study period. Children on chemotherapy for solid tumors should be routinely screened for B19V infection by both serology and PCR. J. Med. Virol. 88:1922-1929, 2016. © 2016 Wiley Periodicals, Inc.

Update of the human parvovirus B19 biology

Since its discovery, the human parvovirus B19 (B19V) has been associated with many clinical situations in addition to the prototype clinical manifestations, i.e. erythema infectiosum and erythroblastopenia crisis. The clinical significance of the viral B19V DNA persistence in sera after acute infection remains largely unknown. Such data may constitute a new clinical entity and is discussed in this manuscript. In 2002, despite the genetic diversity among B19V viruses has been reported to be very low, the description of markedly distinct sequences showed a new organization into three genotypes. The most recent common ancestor for B19V genotypes was estimated at early 1800s. B19V replication is enhanced by hypoxia and this might to explain the high viral load detected by quantitative PCR in the sera of infected patients. The minimum infectious dose necessary to transmit B19V infection by the transfusion of labile blood products remains unclear. At the opposite, the US Food and Drug Administration proposed a limit of 10(4)IU/mL of viral DNA in plasma pools used for the production of plasma derivatives. Recently, a new human parvovirus (PARV4) has been discovered. The consequences on blood transfusion of this blood-borne agent and its pathogenicity are still unknown.

Detection of Human parvovirus B19 (HPVB19) in serum samples from fever-rash ill individuals during the rubella outbreak (2005) in Bulgaria

The present study aimed to determine the involvement of the parvovirus B19 (HPVB19) as an etiological agent in individuals with fever-rash infections but not infected with rubella during the rubella outbreak (2005) in Bulgaria. A total of 194 serum samples with negative results for measles and rubella-specific IgM antibodies were tested in the National Reference Laboratory. The individuals aged 5–52 years (mean age 17.2 ± 10.15) were divided into four age groups: 5–14; 15–24; 25–34; and 35+ years old. Serological (indirect enzyme immunoassay – EIA) and molecular (extraction and detection of HPVB19-DNA) methods were used. A genotyping assay of the NS1-PCR product was proceeded with the MfeI restriction enzyme. Out of the total number of samples, 95 samples (48.97%) tested positive for HPVB19-IgM and 109 (56.18%) for HPVB19-DNA. The results from the genotyping assay revealed that genotype 1 (prototype B19) was dominant in 106 from 109 samples (97.25%), while genotype 3 (prototype V9) was detected in only 3 (2.75%). Subjects whose sera tested positive for IgM and had a positive PCR result formed a group that was most frequently linked (in 40% of cases) to acute infection. The highest prevalence was established in the group of the school-age children (5–14 years). The combined application of serological and molecular methods confirms the etiological role of HPVB19, and including virus genotyping, confirms the involvement of HPVB19 in the etiological palette of febrile rash diseases and provides a correct differential diagnostic approach.

Keeping pace with parvovirus B19 genetic variability: a multiplex genotype-specific quantitative PCR assay

Three genotypes have been identified within the parvovirus B19 species (B19V), and such genetic diversity may have significant implications for the development of molecular detection assays. In the present study, B19V genetic variability has been examined on a subset of genomic sequences available in the NCBI nucleotide database, and a quantitative PCR (qPCR) assay able to detect, differentiate, and quantify all viral variants has been established. The designed primers and probes have been used for the development of alternative detection formats, based on a combined use of intercalating dye and genotype-specific hydrolysis probes. The qPCR assay analytical performances have been determined on the 1st WHO International Reference Panel for Parvovirus B19 Genotypes. The developed qPCR protocols allow for the detection of genotypes 1 to 3 with equal accuracy, and with a limit of detection (LOD) of 200 IU/ml. A comparison of routine performance was carried out with respect to a previously established assay specifically validated on B19V genotype 1. For 130 clinical samples analyzed, 126 showed concordant results (31 positive and 97 negative), while 4 showed discordant results. Overall, the genotype-specific qPCR assay showed a sensitivity of 93.94% and a specificity of 97.94%, with an agreement rate of 96.92%. The proposed qPCR assay and the alternative protocols developed, each with robust performance, may allow choice with respect to operational systems and diagnostic requirements and might contribute to provide a more reliable diagnostic service and epidemiological surveillance of B19 virus.

Parvovirus B19 Achievements and Challenges

Parvovirus B19 is a widespread human pathogenic virus, member of the Erythrovirus genus in the Parvoviridae family. Infection can be associated with an ample range of pathologies and clinical manifestations, whose characteristics and outcomes depend on the interplay between the pathogenetic potential of the virus, its adaptation to different cellular environments, and the physiological and immune status of the infected individuals. The scope of this review is the advances in knowledge on the biological characteristics of the virus and of virus-host relationships; in particular, the interactions of the virus with different cellular environments in terms of tropism and ability to achieve a productive replicative cycle, or, on the contrary, to establish persistence; the consequences of infection in terms of interference with the cell physiology; the process of recognition of the virus by the innate or adaptive immune system, hence the role of the immune system in controlling the infection or in the development of clinical manifestations. Linked to these issues is the continuous effort to develop better diagnostic algorithms and methods and the need for development of prophylactic and therapeutic options for B19V infections.

Molecular and phylogenetic analyses of human Parvovirus B19 isolated from Brazilian patients with sickle cell disease and β-thalassemia major and healthy blood donors

Human Parvovirus B19 (B19V) is a recognized cause of life-threatening conditions among patients with hemoglobinopathies. This study investigates B19V infection in patients with sickle cell disease and β-thalassemia using different experimental approaches. A total of 183 individuals (144 with sickle cell disease and 39 with β-thalassemia major) and 100 healthy blood donors were examined for B19V using anti-B19V IgG enzyme immunoassay, quantitative PCR, DNA sequencing, and phylogenetic analysis. Viremia was documented in 18.6% of patients and 1% of donors, and was generally characterized by low viral load (VL); however, acute infections were also observed. Anti-B19V IgG was detected in 65.9% of patients with sickle cell disease and in 60% of donors, whereas the patients with thalassemia exhibited relatively low seroreactivity. The seroprevalence varied among the different age groups. In patients, it progressively increased with age, whereas in donors it reached a plateau. Based on partial NS1 fragments, all isolates detected were classified as subgenotype 1A with a tendency to elicit genetically complex infections. Interestingly, quasispecies occurred in the plasma of not only patients but also donors with even higher heterogeneity. The partial NS1 sequence examined did not exhibit positive selection. Quantitation of B19V with a conservative probe is a technically and practically useful approach. The extensive spread of B19V subgenotype 1A in patients and donors and its recent introduction into the countryside of the São Paulo State, Brazil were demonstrated; however, it is difficult to establish a relationship between viral sequences and the clinical outcomes of the infection.

Parvovirus transmission by blood products - a cause for concern?

The introduction of dual viral inactivation of clotting factor concentrates has practically eliminated infections by viruses associated with significant pathogenicity over the last 20 years. Despite this, theoretical concerns about transmission of infection have remained, as it is known that currently available viral inactivation methods are unable to eliminate parvovirus B19 or prions from these products. Recently, concern has been raised following the identification of the new parvoviruses, human parvovirus 4 (PARV4) and new genotypes of parvovirus B19, in blood products. Parvoviruses do not cause chronic pathogenicity similar to human immunodeficiency virus or hepatitis C virus, but nevertheless may cause clinical manifestations, especially in immunosuppressed patients. Manufacturers should institute measures, such as minipool polymerase chain reaction testing, to ensure that their products contain no known viruses. So far, human bocavirus, another new genus of parvovirus, has not been detected in fractionated blood products, and unless their presence can be demonstrated, routine testing during manufacture is not essential. Continued surveillance of the patients and of the safety of blood products remains an important ongoing issue.

Inactivation and neutralization of parvovirus B19 Genotype 3

BACKGROUND

Parvovirus B19 (B19V) is a common contaminant of human plasma donations. Three B19V genotypes have been defined based on their DNA sequence. Reliable detection of Genotype 3 DNA has proved problematic because of unexpected sequence variability. B19V Genotype 3 is found primarily in West Africa, but was recently detected in plasma from a North American donor. The safety of plasma-derived medicinal products, with respect to B19V, relies on exclusion of high-titer donations, combined with virus clearance at specific manufacturing steps. Studies on inactivation of B19V are difficult to perform and inactivation of Genotype 3 has not yet been investigated.

STUDY DESIGN AND METHODS

Inactivation of B19V Genotypes 3 and 1 by pasteurization of human serum albumin and incubation at low pH was studied using a cell culture assay for infectious virus particles. Infected cells were detected by reverse transcription-polymerase chain reaction analysis of virus capsid mRNA. Neutralization of B19V Genotype 3 was investigated using human immunoglobulin preparations.

RESULTS

Genotypes 1 and 3 displayed comparable inactivation kinetics during pasteurization of albumin at 56°C, as well as by incubation at various low-pH conditions (pH 4.2 at 37°C and pH 4.5 at 23°C, respectively) used in immunoglobulin manufacturing. Both Genotypes were readily neutralized by pooled immunoglobulin preparations of North American or European origin.

CONCLUSION

Pasteurization and low-pH treatment were equally effective in inactivating B19V Genotypes 1 and 3. Neutralization experiments indicated that pooled immunoglobulin of North American or European origin is likely to be equally effective in treatment of disease induced by both genotypes.