B19V Infection Research Articles

Parvovirus B19 induces cellular senescence in human dermal fibroblasts: putative role in systemic sclerosis-associated fibrosis.

ObjectiveEmerging evidence demonstrates that excessive accumulation of senescent cells is associated with some chronic diseases and suggests a pathogenic role of cellular senescence in fibrotic processes, such as that occurring in ageing or in SSc. Recently we demonstrated that parvovirus B19 (B19V) activates normal human dermal fibroblasts and induces expression of different profibrotic/pro-inflammatory genes. This observation prompted us to investigate whether it is also able to induce fibroblast senescence as a potential pathogenetic mechanism in B19V-induced fibrosis.MethodsPrimary cultures of fibroblasts were infected with B19V and analysed for the acquisition of senescence markers, such as morphological modifications, senescence-associated β-galactosidase (SA-β-gal) activity, DNA damage response and expression of senescence-associated secretory phenotype (SASP)-related factors.ResultsWe demonstrated that B19V-infected fibroblasts develop typical senescence features such as enlarged and flat-shaped morphology and SA-β-gal activity similar to that observed in SSc skin fibroblasts. They also developed an SASP-like phenotype characterized by mRNA expression and release of some pro-inflammatory cytokines, along with activation of the transcription factor nuclear factor κB. Moreover, we observed B19V-induced DNA damage with the comet assay: a subpopulation of fibroblasts from B19V-infected cultures showed a significantly higher level of DNA strand breaks and oxidative damage compared with mock-infected cells. An increased level and nuclear localization of γH2AX, a hallmark of DNA damage response, were also found.ConclusionsB19V-induced senescence and production of SASP-like factors in normal dermal fibroblasts could represent a new pathogenic mechanism of non-productive B19V infection, which may have a role in the fibrotic process.

Guillain-Barre´ Syndrome

Guillain-Barre´ syndrome (GBS) is characterized by rapidly evolving symmetrical limb weakness, loss of tendon reflexes, absent or mild sensory signs, and variable autonomic dysfunction. It occurs most commonly after a respiratory tract or a gastrointestinal infection. Campylobacter jejune and cytomegalovirus (CMV) constitute the most frequent bacterial and viral triggers. Epstein-Barr virus (EBV), Mycoplasma pneumonia, and human immunodeficiency virus (HIV) have also been associated with GBS whereas parvovirus B19 (B19V) is not usually cited as a cause of GBS. We report a case of GBS in a chronically HIV-infected patient in association with a primary B19V infection.

Parvovirus B19 and Pregnant Women: A Bibliographic Review

Parvovirus B19 (PVB19) is one of the smallest viruses that are known to infect humans [1]. The clinical manifestations of B19V infection vary greatly and depend on age, hematologic and immunologic status. In immunocompetent individuals, the infection can be completely asymptomatic or can cause mild and self-limiting clinical manifestations such as erythema infectiosum or fifth disease during childhood, arthralgias and arthritis in adults, particularly in women [2,3], chronic hemolytic anemia, and fetal death in utero or non-immune hydrops fetalis in pregnant women [4]. Due to the efficient replication of B19V in the erythroid progenitor cells [5]. In temperate climates, the infection may occur throughout the year, Infection is most common in late winter or early spring [6]. During pregnancy, the virus is transmitted through exposure to infected respiratory droplets or blood products and vertically from mother to fetus [7,8]. The vertical transmission of B19 occurs in about one-third of women infected [9].The proportion of pregnant women susceptible to B19 infection ranges from 34% to 65% in various parts of the world. The incidence of seroconversion during pregnancy is estimated at between 1% and 1, 5% in the endemic period, increasing to 13% in the epidemic period [10]. Non-immune women are most likely to be infected by young children [11]. Parvovirus infection of mothers is diagnosed using serologic or an immune assay enzyme B19 IgM and B19 IgG [12]. Viral DNA can be detected by Polymerase Chain Reaction (PCR) and is considered to be the best indicator of infection in maternal, fetal blood, and amniotic fluid [13]. In these conditions, it seemed necessary to us to study this virus in this article and to answer the various practical questions raised by the occurrence of contagion and/or infection with Parvovirus B19 during pregnancy.

High-Throughput Screening Identifies Inhibitors for Parvovirus B19 Infection of Human Erythroid Progenitors.

Parvovirus B19 (B19V) infection can cause hematological disorders and fetal hydrops during pregnancy. Currently, no antivirals or vaccines are available for the treatment or prevention of B19V infection. To identify novel small-molecule antivirals against B19V replication, we developed a high-throughput screening (HTS) assay, which is based on an in vitro nicking assay using recombinant N-terminal amino acids 1 to 176 of the viral large nonstructural protein (NS1N) and a fluorescently labeled DNA probe (OriQ) that spans the nicking site of the viral DNA replication origin. We collectively screened 17,040 compounds and identified 2,178 (12.78%) hits that possess >10% inhibition of the NS1 nicking activity, among which 84 hits were confirmed to inhibit nicking in a dose-dependent manner. Using ex vivo-expanded primary human erythroid progenitor cells (EPCs) infected by B19V, we validated 24 compounds that demonstrated >50% in vivo inhibition of B19V infection at 10 μM, which can be categorized into 7 structure scaffolds. Based on the therapeutic index (half-maximal cytotoxic concentration [CC50]/half-maximal effective concentration [EC50] ratio) in EPCs, the top 4 compounds were chosen to examine their inhibitions of B19V infection in EPCs at two times of the 90% maximal effective concentration (EC90). A purine derivative (P7) demonstrated an antiviral effect (EC50 = 1.46 μM) without prominent cytotoxicity (CC50 = 71.8 μM) in EPCs and exhibited 92% inhibition of B19V infection in EPCs at 3.32 μM, which can be used as the lead compound in future studies for the treatment of B19V infection-caused hematological disorders. IMPORTANCE B19V encodes a large nonstructural protein, NS1. Its N-terminal domain (NS1N) consisting of amino acids 1 to 176 binds to viral DNA and serves as an endonuclease to nick the viral DNA replication origins, which is a pivotal step in rolling-hairpin-dependent B19V DNA replication. For high-throughput screening (HTS) of anti-B19V antivirals, we miniaturized a fluorescence-based in vitro nicking assay, which employs a fluorophore-labeled probe spanning the terminal resolution site (trs) and the NS1N protein, into a 384-well-plate format. The HTS assay showed high reliability and capability in screening 17,040 compounds. Based on the therapeutic index (half-maximal cytotoxic concentration [CC50]/half-maximal effective concentration [EC50] ratio) in EPCs, a purine derivative demonstrated an antiviral effect of 92% inhibition of B19V infection in EPCs at 3.32 μM (two times the EC90). Our study demonstrated a robust HTS assay for screening antivirals against B19V infection.

Donor-Derived Human Parvovirus B19 Infection in Kidney Transplantation.

BackgroundDonor-derived human parvovirus B19 (B19V) infections are rarely reported. Thus, its incidence in kidney transplantation is still unknown due to lack of surveillance studies. Similarly, whether the donor needs to be routinely screened for B19V and whether the kidneys from those with B19V DNAemia could be accepted also remain unknown.MethodsThis retrospective study aims to evaluate the donor-derived B19V infections occurring in 823 living and 1,225 deceased donor kidney transplantations from January 2016 to December 2020. The serum viral load of living donors and their corresponding recipients was evaluated before and after transplantation. Meanwhile, for the deceased donor kidney transplantation, the serum viral load of recipients was only tested after transplantation; if recipients of a deceased donor subsequently developed B19V infection, the serum viral load of recipients and their corresponding donors before transplantation would then be further traced.ResultsA total of 15 living donors were B19V DNAemia positive before the donation, of which B19V DNAemia occurred in three corresponding recipients. In deceased donor kidney transplantation, DNAemia occurred simultaneously in 18 recipients and their corresponding nine donors. A progressive decline in hemoglobin and reticulocyte count could be observed in one living donor recipient and other 11 deceased donor recipients, which were all well controlled by treatment eventually.ConclusionThe incidence of donor-derived B19V infection was 0.4% and 1.5% in living and deceased kidney transplantations, respectively. B19V was seemingly unnecessary to be routinely screened for the donor. Moreover, kidneys of the donors with B19V infection were acceptable.

Parvovirus b19 infection in pregnancy – A review

Parvovirus B19 (B19V) is a widespread infection that may affect 1–5% of pregnant women, mainly with normal pregnancy outcome. Vertical transmission occurs in 33–51% of cases of maternal infection. B19V infection is an important cause of fetal morbidity (fetal anaemia and non-immune hydrops) and mortality, predominantly in the second trimester.Diagnosis of B19V infection requires a multi-method approach using mainly serology and PCR techniques. Severe fetal anaemia is managed with intrauterine transfusion with perinatal survival rates following intrauterine transfusion ranging from 67% to 85%. If fetal anaemia is mild, and considering that hydrops can spontaneously resolve, invasive therapy is not recommended and B19V complicated pregnancy may be non-invasively monitored by serial ultrasound examination and MCV-PSV measurements. As an alternative, intrauterine IVIG therapy has been described with successful treatment of fetal hydrops.No specific antiviral therapy or vaccine is presently available for B19V infection but efforts in the search for compounds inhibiting B19V replication are now being pursued. New virus-like-particle based parvovirus B19 vaccine candidates, produced by co-expressing VP2 and either wild-type VP1 or phospholipase-negative VP1 in a regulated ratio from a single plasmid inSaccharomyces cerevisiae have been developed and show sufficient promise to test in humans.

The N-terminal 5-68 amino acids domain of the minor capsid protein VP1 of human parvovirus B19 enters human erythroid progenitors and inhibits B19 infection.

Parvovirus B19 (B19V) infection causes diseases in humans ranging from the mild erythema infectiosum to severe hematological disorders. The unique region of the minor structural protein VP1 (VP1u) of 227 amino acids harbors strong neutralizing epitopes which elicit dominant immune responses in patients. Recent studies have shown that the VP1u selectively binds to and enters B19V permissive cells through an unknown cellular proteinaceous receptor. In the present study, we demonstrated that purified recombinant VP1u effectively inhibits B19V infection of ex vivo expanded primary human erythroid progenitors. Furthermore, we identified the amino acid sequence 5-68 of the VP1 (VP1u5-68aa) is sufficient to confer the inhibition of B19V infection at a level similar to that of the full-length VP1u. In silico structure prediction suggests that the VP1u5-68aa contains three α-helices. Importantly, we found that the inhibition capability of the minimal domain VP1u5-68aa is independent of its dimerization but is likely dependent on the structure of the three predicated α-helices. As VP1u5-68aa outcompetes the full-length VP1u in entering cells, we believe that VP1u5-68aa functions as a receptor-binding ligand during virus entry. Finally, we determined the effective inhibition potency of VP1u5-68aa in B19V infection of human erythroid progenitors, which has a half maximal effective concentration (EC50) of 67 nM, suggesting an anti-viral peptide candidate to combat B19V infection.IMPORTANCEHuman parvovirus B19 infection causes severe hematological disorders, including transient aplastic crisis, pure red cell aplasia, and hydrops fetalis. A productive B19 infection is highly restricted to human erythroid progenitors in human bone marrow and fetal liver. In the current study, we identified that the N-terminal 5-68 amino acids domain of the minor viral capsid protein VP1 enters ex vivo expanded human erythroid progenitors, which is nearly 5 times more efficient than the full-length VP1 unique region (1-227aa). Importantly, purified recombinant 5-68aa of the VP1 has a high efficiency in inhibition of parvovirus B19 infection of human erythroid progenitors, which has a half maximal effective concentration (EC50) of 67 nM and a low cytotoxicity. The N-terminal 5-68 amino acids holds the potential as an effective antiviral of parvovirus B19 caused hematological disorders, as well as a carrier to deliver proteins to human erythroid progenitors.

Parvovirus B19 DNA detectable in hearts of patients with dilated cardiomyopathy, but absent or inactive in blood.

AimsParvovirus B19 (B19V) is often assumed to be a cause of dilated cardiomyopathy (DCM), based on the quantification of B19V DNA in endomyocardial biopsies (EMB). Whether the presence of B19V DNA correlates with active infection is still debated. Application of the enzyme endonuclease to blood samples results in degradation of B19V DNA remnants but leaves viral particles intact, which enables differentiation between active and past infection. In this study, the susceptibility to degradation by endonuclease of B19V DNA in blood was compared between DCM patients and a control group of recent B19V infections.Methods and resultsTwenty blood samples from 20 adult patients with DCM, who previously tested positive for B19V DNA in EMB and/or blood, were tested with B19V PCR before and after application of endonuclease to the samples. Six blood samples tested positive for B19V DNA with a mean viral load of 2.3 × 104 IU/mL. In five samples, B19V DNA became undetectable after endonuclease (100% load reduction); in one sample DNA load showed a 23% log load reduction (viral load before endonuclease: 9.1 × 104 IU/mL; after: 6.5 × 103 IU/mL). Presence of cardiac inflammation did not differ between patients with B19V DNAemia (1/4) and patients without B19V DNAemia (6/14) ( P value = 1.0). In all 18 control samples of proven recent B19V infections, DNA remained detectable after application of endonuclease, showing only a mean log load reduction of 2.3% (mean viral load before endonuclease: 8.1 × 1011 IU/mL; after: 8.0 × 1011 IU/mL). Load reduction differed significantly between the DCM group and the control group; indicating the presence of intact viral particles in the control group with proven active infection and the presence of DNA remnants in the DCM group (P value = 0.000).ConclusionDuring recent B19V infection, viral DNA levels in blood were unaffected by endonuclease. In contrast, B19V DNA in blood in patients with DCM became undetectable or strongly reduced after application of endonuclease. Circulating viral DNA in this subset of patients with presumed parvovirus‐associated DCM does not consist of intact viral particles. Viral replicative activity cannot be assumed from demonstrating B19V DNA in cardiac tissue or in blood in DCM patients.

Nucleoside Analogue Reverse Transcriptase Inhibitors Improve Clinical Outcome in Transcriptional Active Human Parvovirus B19-Positive Patients.

Human parvovirus B19 (B19V) is the predominant cardiotropic virus associated with dilated inflammatory cardiomyopathy (DCMi). Transcriptionally active cardiotropic B19V infection is clinically relevant and triggers adverse long-term mortality. During the study; we evaluated whether antiviral treatment with the nucleoside analogue telbivudine (LTD) is effective in suppressing transcriptional active B19V in endomyocardial biopsies (EMBs) of B19V positive patients and improving clinical outcomes. Seventeen B19V-positive patients (13 male; mean age 45.7 ± 13.9 years; mean left ventricular ejection fraction (LVEF) 37.7 ± 13.5%) with positive B19V DNA and transcriptional activity (B19V mRNA) in EMBs were treated with 600 mg/d LTD over a period of six months. Patients underwent EMBs before and after termination of the LTD treatment. B19V RNA copy numbers remained unchanged in 3/17 patients (non-responder) and declined or disappeared completely in the remaining 14/17 patients (responder) (p ≤ 0.0001). Notably; LVEF improvement was more significant in patients who reduced or lost B19V RNA (responder; p = 0.02) in contrast to non-responders (p = 0.7). In parallel; responder patients displayed statistically significant improvement in quality of life (QoL) questionnaires (p = 0.03) and dyspnea on exertion (p = 0.0006), reflecting an improvement in New York Heart Association (NYHA) Classification (p = 0.001). Our findings demonstrated for the first time that suppression of B19V transcriptional activity by LTD treatment improved hemodynamic and clinical outcome significantly. Thus; the present study substantiates the clinical relevance of detecting B19V transcriptional activity of the myocardium.

Serological detection of human parvovirus B19 infection and associated risk factors among pregnant women in Jigawa State, Nigeria

ABSTRACT Human Parvovirus B19 (B19 V) infection is hyperendemic in Nigeria. Pregnant women are not classically immunocompromised but maybe physiologically immunosuppressed and susceptible to viral infection. However, there is a paucity of studies on the epidemiology of B19V in Jigawa State, Northwestern Nigeria. This study aims to determine the seroprevalence, sociodemographic, and risk factors of human B19V infection among present women attending antenatal clinics of Jahun General Hospital, Nigeria. Between 2 February and 30 June 2019, blood samples were collected from 200 consented pregnant women and analyzed for anti-B19V IgM and IgG using commercially available enzyme-linked immunosorbent assay (ELISA). Sociodemographic and risk factors of subjects were collated through pre-tested structured questionnaires. Data generated were statistically analyzed for the association of anti-B19V and subjects’ variables studied. Overall, the seroprevalence of anti-B19V IgM and IgG among pregnant women attending antenatal clinics of Jahun General Hospital, Nigeria was 6.0% and 22.5%, respectively. There was no significant association between the seroprevalence of anti-B19V IgM and anti-B19V IgG with all the sociodemographic variables and risk factors of pregnant women (P ˃0.05). However, pregnant women with a history of blood transfusion had a significant risk associated with seroprevalence of B19V IgM (OR = 5.95; 95% CI: 1.96–22.76; P = .009). Findings from this study revealed that a high proportion of the pregnant women were susceptible to B19V infection and anti-B19V IgG immunity decreased with age. Given the incidence of acute B19V infection, it is clinically important to continuously monitor their erythrocytes indices and screen their neonates for B19V infection and fetal complications.

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.

Human parvovirus B19: a review of clinical and epidemiological aspects in Brazil.

Since the first evidence of human parvovirus B19 (B19V) infection in late 80s, several studies have been conducted to clarify the spectrum of clinical diseases in Brazil. B19V infection is prevalent in the general population and has exhibited a cyclical pattern of occurrence every 4-5years, with the predominance of genotype 1 over 3b. During epidemic periods the wide range of clinical conditions, such as ertythema infectiosum, arthropathy, transient aplastic crisis, nonimmune hydrops fetalis and B19V-hepatitis were diagnosed. However, many infections are likely asymptomatic or have a self-limiting clinical course and are not readly diagnosed. Besides, the similarity of the symptoms of ertythema infectiosum to other rash diseases and the broadly circulation of arboviruses makes differential diagnosis more difficult. In this article, we provide a historical comprehensive overview of the research on parvovirus B19 conducted in Brazil, with a focus on the clinical and epidemiological aspects of the infection.

Molecular and serological markers of human parvovirus B19 infection in blood donors: A systematic review and meta-analysis.

BACKGROUND:Human parvovirus B19 (B19V) is one of the blood-borne viruses. The virus can be transmitted to susceptible individuals by blood or blood products. The virus is not associated with significant disease in general population, while people with underlying problems such as immunodeficiency can cause anemia and arthritis. The current systematic review and meta-analysis aimed to estimate the overall prevalence of B19V DNA, anti-B19V IgG, and anti-B19V IgM antibodies in blood donors worldwide.METHODS:A systematic search was carried out in online databases for relevant studies from inception until March 30, 2019. Study selection was performed based on predesigned eligibility criteria. The proportion of B19V DNA, anti-B19V IgG, and anti-B19V IgM antibodies were pooled using the inverse variance method. All statistical analyses were performed using the R version 3.5.3, package “meta.”RESULTS:According to the random-effects model, the pool prevalence of B19V DNA, anti-B19V IgM, and anti-B19V IgG among blood donors was calculated to be 0.4% (95% confidence interval [CI] =0.3%–0.6%), 2.2% (95% CI = 1.3%–3.7%), and 50.1% (95% CI = 43.1%–57.1%), respectively.CONCLUSION:For the transmission of B19V through blood, the presence of the virus genome is required, and the present study showed that the prevalence of the virus genome in blood donors is <1%. Therefore, there is no need to screen donated blood for B19V infection.

The VP1u of Human Parvovirus B19: A Multifunctional Capsid Protein with Biotechnological Applications.

The viral protein 1 unique region (VP1u) of human parvovirus B19 (B19V) is a multifunctional capsid protein with essential roles in virus tropism, uptake, and subcellular trafficking. These functions reside on hidden protein domains, which become accessible upon interaction with cell membrane receptors. A receptor-binding domain (RBD) in VP1u is responsible for the specific targeting and uptake of the virus exclusively into cells of the erythroid lineage in the bone marrow. A phospholipase A2 domain promotes the endosomal escape of the incoming virus. The VP1u is also the immunodominant region of the capsid as it is the target of neutralizing antibodies. For all these reasons, the VP1u has raised great interest in antiviral research and vaccinology. Besides the essential functions in B19V infection, the remarkable erythroid specificity of the VP1u makes it a unique erythroid cell surface biomarker. Moreover, the demonstrated capacity of the VP1u to deliver diverse cargo specifically to cells around the proerythroblast differentiation stage, including erythroleukemic cells, offers novel therapeutic opportunities for erythroid-specific drug delivery. In this review, we focus on the multifunctional role of the VP1u in B19V infection and explore its potential in diagnostics and erythroid-specific therapeutics.

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.

Detection of parvovirus mRNAs as markers for viral activity in endomyocardial biopsy-based diagnosis of patients with unexplained heart failure.

Erythroparvovirus (B19V) genomes have been detected in various organs of infected individuals including endothelial cells of the heart muscle. However, the role of B19V as a causative pathogen of myocardial damage is still unknown. The majority of reports focus on the presence of viral DNA ignoring proof of viral RNAs as important markers for viral activity. During this study, we established (RT-) qPCR to characterize expression of B19V RNAs (NS1 and VP1/2) in endomyocardial biopsies (EMBs) of 576 patients with unexplained heart failure. 403/576 (70%) EMBs were positive for B19V DNA. B19V mRNAs NS1 and/or VP1/2, indicating viral activity, could be detected in 38.5% of B19V DNA positive samples using the newly established B19V RT-PCRs. 22.1% of samples were characterized by only NS1 mRNA detection while 6.0% revealed only VP1/2 mRNA expression. Detection of both intermediates was successful in 10.4% of samples. Applying the molecular testing, our study revealed that a high proportion (38.5%) of B19V DNA positive EMBs was characterized by viral transcriptional activity. Further prospective studies will evaluate relevance of viral transcription intermediates as a diagnostic marker to differentiate between latent B19V infection and clinically relevant transcriptionally active B19V-infection of the heart muscle.

Parvovirus B19 NS1 and VP1/2 mRNAs expression indicates viral activity in endomyocardial biopsy-based diagnosis of patients with unexplained heart failure

Abstract Background Human erythroparvovirus-1 (B19V) is the most frequently found virus in endomyocardial biopsies (EMBs). Recent studies have detected B19V genomes in various organs of symptomatic and asymptomatic individuals including endothelial cells of the heart muscle. Accordingly, B19V as a causative pathogen of myocardial damage has been questioned. To date, the majority of studies focused on the presence of viral DNA in the myocardium, but lack the analysis of viral RNAs as markers for viral activity. In contrast to latent infection, the expression of viral mRNAs is of clinical importance as we could demonstrate in previous studies. Only recently, novel antiviral treatment strategies have become available. A sensitive and specific method to identify and monitor patients that will profit from antiviral treatment is a prerequisite for successful therapy. During this study, we established a new PCR-based diagnostic method to characterize the expression of B19V RNAs coding for the non-structural (NS1) and capsid protein (VP1/2) in endomyocardial biopsies of patients with unexplained heart failure and demonstrated its feasibility in a clinical setting of molecular diagnostics. Methods To quantify B19V RNA expression, we developed real-time (reverse transcription) polymerase chain reactions (qPCRs) targeting the NS1 and VP1/2 regions of B19V genome. 576 randomly selected EMBs of patients with unexplained heart failure were tested for B19V genomes and transcription intermediates using qPCR and nested PCR. Results 403 of 576 (69.9%) EMBs were positive for B19V genomes (B19V DNA). Viral loads ranged from 15 to 51,118 genome equivalents/μg isolated DNA. Of the 403 B19V DNA-positive samples, B19V mRNAs NS1 and/or VP1/2, indicating viral activity, could be detected in 155/403 (38.4%) EMBs using the newly established B19V qPCRs. 89/403 samples were characterized by only NS1 mRNA detection while 24/403 revealed only VP1/2 mRNA expression. Detection of both intermediates was successful in 42/403 samples. Patients characterized by active B19V infection presented with a significantly reduced left ventricular ejection fraction (30.7±13.1%) in contrast to virus free patients (35.5±15.9%; p=0.025) or latently infected patients (34.7±15.7; p=0.043). Conclusion Our newly established molecular testing will improve detection and quantification of B19V. As we could demonstrate here, it is essential to screen for both viral transcription intermediates, the NS1 and VP1/2 viral mRNAs, in order to precisely differentiate between latent infection or a clinically relevant B19V-infection with transcriptional activity of the heart muscle. The results of our study revealed that a remarkable high proportion of 26.9% (155/576) of patients with unexplained heart failure is affected by transcriptional active B19V infection of the myocardium. Prospective studies must be conducted to evaluate our findings and furthermore, effective antiviral treatment strategies need to be adapted. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): IKDT GmbHn

Identification and management of congenital parvovirus B19 infection.

Parvovirus B19 (B19V) infection is well known for its mild, self-limiting clinical presentations in children, such as erythema infectiosum. Approximately 40% of women of childbearing age are susceptible to B19V infection. While maternal B19V infection usually has a good prognosis, B19V can cause severe fetal anaemia and pregnancy loss due to its ability to suppress erythroid progenitor cells. Non-invasive ultrasound monitoring for fetal anaemia is usually performed if maternal seroconversion occurs in the first 20 weeks of gestation, with amniocentesis for fetal infection reserved for those who first present with fetal anaemia or hydrops of unknown cause. Intrauterine transfusion is the standard treatment for severe fetal anaemia and is associated with a significant improvement in survival. However, survivors of hydrops fetalis may have a higher rate of long-term neurodevelopmental complications compared with non-hydropic survivors. This review aims to synthesise published data on the diagnosis, surveillance and outcomes of congenital parvovirus infection to assist clinicians in diagnosing and managing this important condition.

Risks for adverse pregnancy outcomes and infections in daycare workers: an overview of current epidemiological evidence and implications for primary prevention.

Childcare providers are overwhelmingly women of childbearing age. Occupational risks in this sector include exposure to biological (infectious) or physical (standing, carrying loads) hazards, many of which are associated with adverse pregnancy outcomes such as children with congenital infections, low birth weight or prematurity. Here, the authors examined literature on pregnancy outcomes and infectious hazards related to employment in daycare settings. Overall, 33 original studies (10 reporting pregnancy issues, 23 focusing on infectious risks) published in 1980-2018 were retained following a Medline search. Pregnancy issues in daycare workers have rarely been studied, and inconsistent risks of spontaneous abortion, congenital malformations and fetal growth retardation have been reported. Literature pertaining to infectious risks in daycare settings is extensive. The risk of a primary cytomegalovirus infection during pregnancy was increased for daycare workers caring for >6 children and younger children, changing diapers ≥3 days/week, not wearing gloves when changing diapers, and having employment in daycare for ≤2 years. Personal factors (nulliparity, ethnicity) were also independent risk factors. Parvovirus B19 (B19V) infections appear to be related to employment in daycare, but also to having one's own children and an increased number of siblings. Consequently, the risk of a primary B19V infection during an outbreak is of most concern among younger nulliparous workers caring for large numbers of young infected children. Since the main occupational hazard is viral infection, feasible prevention strategies include improving workers' awareness, serological monitoring during pregnancy, educating on appropriate preventive measures, and ensuring age-appropriate immunization of children and staff in childcare facilities. Int J Occup Med Environ Health. 2020;33(6):733-56.

A cross-sectional study on risk factors for infection with Parvovirus B19 and the association with anaemia in a febrile paediatric population in Ghana

Parvovirus B19 (B19V) occurs globally and can cause severe anaemia. The role of co-infections with Plasmodium falciparum (P. falciparum) has been controversially discussed. The study aimed to determine prevalence and severity of B19V infection, and the effect of co-infections on the risk for anaemia. Between November 2013 and April 2015 a total of 1186 hospital visits of children with fever admitted to a hospital in Ghana were recorded. Malaria, B19V and additional diagnostics for fever causes were performed. Recent B19V infection was defined as PCR and/or IgM positivity. Risk factors for a B19V infection and for anaemia were analysed. The prevalence of anaemia was compared between children with/without B19V infection, stratified for the presence of malaria. B19V IgM/PCR was positive in 6.4% (n = 76; 40 IgM + , 30 PCR + , 6 IgM + and PCR +). Among the B19V cases 60.5% had a simultaneous P. falciparum infection. B19V IgM positivity but not PCR positivity was associated with moderate-severe anaemia (OR = 2.6; 95%-CI: 1.3–5.3; P < 0.01 vs. OR = 0.9; 95%-CI: 0.4–1.8; P = 0.70). P. falciparum and IgM positive B19V infection were independent risk factors for anaemia with no evidence of effect modification. Our data show a significant association between B19V infection, defined as IgM but not PCR positivity, and moderate-severe anaemia. A multiplicative effect of B19V and P. falciparum infection was not found.