The risk of maternal parvovirus B19 infection during pregnancy on fetal loss and fetal hydrops: A systematic review and meta-analysis

STORCH Brazil: multicenter cohort study protocol to investigate neurodevelopmental paths and functioning in infants exposed to STORCH in Brazil

BACKGROUND

The acronym STORCH encompasses gestational infections that can lead to congenital syndromes or adverse neurological outcomes in children. In Brazil and worldwide, there has been an alarming increase in confirmed cases of STORCH in recent years. However, no study has examined the impact of STORCH on infants' neurodevelopmental outcomes in a large, multi-center cohort, recruiting a substantial number of participants, with analysis across a broad set of variables and ages and based on the International Classification of Functioning, Disability and Health (ICF) model.

OBJECTIVE

To examine the association between the exposure to classic STORCH (syphilis, toxoplasmosis, rubella, cytomegalovirus infection, and herpes simplex) on components of functioning in infants from 3 to 24 months old in Brazil.

METHODS

We propose a multi-center prospective cohort study that includes data collection in at least one city from each geographical region of Brazil. A proposed total sample size of 296 infants will be included at 3 months (12-15 weeks post term). They will be equitably divided into: (a) an exposed group (n = 148), consisting of those diagnosed with any congenital STORCH infection or whose mothers experienced prenatal STORCH infection; (b) an unexposed group (n = 148). Assessments are carried out longitudinally at 3, 6, 9, 12, 18, and 24 months of age. Assessment tools include Prechtl's General Movements Assessment, Hammersmith Infant Neurological Examination, Alberta Infant Motor Scale; Bayley Scales of Infant and Toddler Development; Survey of Well-being of Young Children; Autism Observational Scale for Infants; Modified Checklist for Autism in Toddlers; Child Behavior Checklist; and Young Children's Participation and Environment Measure. Descriptive analyses, including the calculation of relative risk, and logistic regressions will be conducted to examine the association between gestational exposure to STORCH agents and infants' responses/outcomes.

DISCUSSION

The STORCH Brazil study will investigate the impact of STORCH exposure on functioning, including neurodevelopmental trajectories, in infants during their first two years, aligning with the ICF framework. This will enhance understanding of the characteristics and needs of STORCH-exposed infants, aiding therapists in making informed clinical decisions. The results might support public policies tailored to this population. Findings will be disseminated to ensure knowledge translation.

CLINICAL TRIAL NUMBER

Not applicable.

Parvovirus B19 in Pregnancy-Do We Screen for Fifth Disease or Not?

Parvovirus B19 (B19V) infection is the cause of erythema infectiosum, or the "fifth disease", a widespread infection, potentially affecting 1-5% of pregnant women, in most cases without significant damage to the pregnancy or fetus. It follows a seasonal variation, with a higher prevalence in temperate climates, mainly in late winter and early spring. Women at increased risk include mothers of preschool and school-age children, and those working in nurseries, kindergartens, and schools. Vertical transmission occurs in 33% to 51% of cases of maternal infection. Parvovirus infection is an important cause of fetal perinatal infection resulting in increased morbidity through the development of fetal anemia, heart failure, and non-immune hydrops. A comprehensive literature review was conducted using PubMed, Cochrane Library, and Google Scholar, focusing on publications from the last 10 years and prioritizing studies related to parvovirus B19 infection in pregnancy. We summarized the existing data in the literature on the effects of parvovirus B19 infection during pregnancy and weighed if there is a need for screening in pregnant patients. Routine screening for parvovirus B19 infection can be considered in communities where infection is common, there is occupational exposure, or during endemic periods, with the reason being that accurate identification and treatment of fetuses affected by congenital B19V infection have been shown to improve perinatal outcomes.

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.

Prenatal parvovirus B19 infection

Parvovirus B19 (B19V) causes erythema infectiosum, a.k.a., fifth disease. This disease primarily affects children. It is generally self-limiting and subsides after 1-2 weeks. In pregnancy, the virus can cross the placenta and result in a fetal infection. This may lead to severe fetal anemia, hydrops fetalis, a miscarriage, or intrauterine fetal death. The risk of long-term sequelae also appears to be increased. About one-third of pregnant women are not immune to B19V and, therefore, are at risk to contract a primary infection. The seroconversion rate during pregnancy is generally around 1-2%. During a primary infection, maternal-fetal transplacental transmission of B19V occurs in about 30-50% of the cases and the risk of fetal infection increases with advancing gestational age. The risk of severe fetal anemia or hydrops is around 3-4% overall and is around 6-7% if the primary infection occurs before 20 weeks' gestation. Fetal monitoring in women with a primary B19V infection includes regular ultrasound examinations looking for evidence of hydrops fetalis and Doppler measurements of the middle cerebral artery peak velocity. Fetal blood sampling is performed if a significant anemia is suspected and, if such is found, an intrauterine blood transfusion is needed. This article provides an overview of the epidemiology, pathogenesis, clinical manifestations, diagnostic methods, and management of B19V infection during pregnancy.

Parvovirus B19 Infection and Pregnancy: Review of the Current Knowledge

Parvovirus B19, a member of the Parvoviridae family, is a human pathogenic virus. It can be transmitted by respiratory secretions, hand-to-mouth contact, blood transfusion, or transplacental transmission. Most patients are asymptomatic or present with mild symptoms such as erythema infectiosum, especially in children. In rare cases, moderate-to-severe symptoms may occur, affecting blood cells and other systems, resulting in anemia, thrombocytopenia, and neutropenia. Non-immune pregnant women are at risk for fetal infection by parvovirus B19, with greater complications if transmission occurs in the first or second trimester. Infected fetuses may not show any abnormalities in most cases, but in more severe cases, there may be severe fetal anemia, hydrops, and even pregnancy loss. Maternal diagnosis of intrauterine parvovirus B19 infection includes IgG and IgM antibody testing. For fetal diagnosis, PCR is performed through amniocentesis. In addition to diagnosing the infection, it is important to monitor the peak of systolic velocity of the middle cerebral artery (PVS-MCA) Doppler to assess the presence of fetal anemia. There is no vaccine for parvovirus B19, and fetal management focuses on detecting moderate/severe anemia by fetal PVS-MCA Doppler, which, if diagnosed, should be treated with intrauterine transfusion by cordocentesis. Prevention focuses on reducing exposure in high-risk populations, particularly pregnant women.

How do we perform intrauterine transfusions?

BACKGROUND

Intrauterine transfusion (IUT) is an invasive but critical and potentially life-saving intervention for severe fetal anemia with demonstrated improvement in outcomes. The fetus is vulnerable to hemodynamic alterations and transfusion-related adverse events; therefore, special consideration must be given to blood component selection and modification. There is widespread IUT practice variability, and existing guidance primarily relies on expert opinion and single center experiences.

STUDY DESIGN AND METHODS

Experts in Maternal Fetal Medicine, Pediatric Hematology, and Transfusion Medicine from centers across the United States, collectively performing about 120 IUT annually, offer a multidisciplinary perspective on the performance of IUT and preparation of blood components. This perspective includes strategies for identifying an at-risk fetus, communicating between disciplines, determining the necessary blood volume, selecting and processing blood components, documenting the procedure in medical record, and managing the neonate.

RESULTS

Identifying an at-risk fetus relies on review of the clinical history, non-invasive monitoring, and laboratory evaluation. We recommend the use of relatively fresh, group O, cytomegalovirus-safe, freshly irradiated, red blood cells (RBC) that are Hemoglobin S negative and antigen-negative for any maternal antibody, if indicated. These RBC units should be concentrated to remove additives and increase the hematocrit thus minimizing fluctuations in fetal volume status. The units intended for IUT should be labeled clearly and the documentation of transfusion differentiated in the maternal medical record.

DISCUSSION

An awareness of the technical, logistical, and regulatory considerations for IUT performance will facilitate improved communication and patient care, especially when rare units of RBC are required.

Detection of coinfection with Primate Erythroparvovirus 1 and arboviruses (DENV, CHIKV and ZIKV) in individuals with acute febrile illness in the state of Rio Grande do Norte in 2016

BACKGROUND

Arthropod-borne viruses, known as arboviruses, pose substantial risks to global public health. Dengue (DENV), Chikungunya (CHIKV) and Zika (ZIKV) viruses stand out as significant concerns in Brazil and worldwide. Their overlapping clinical manifestations make accurate diagnosis a challenge, underscoring the need for reliable laboratory support. This study employs a comprehensive molecular diagnostic approach to track viral infections in individuals with acute febrile illness, a period marked by widespread outbreaks of DENV, CHIKV and ZIKV.

METHODS

Between January and August 2016, we received a total of 713 serum samples obtained from individuals with acute febrile illness, previously tested for DENV, CHIKV or ZIKV, with initial negative results, from LACEN-NATAL. Of the total 713 samples, 667 were from females (354 of them pregnant) and 46 from males. Molecular diagnosis was conducted using the Multiplex RT-qPCR technique for simultaneous detection of DENV, CHIKV and ZIKV. Additionally, we performed differential diagnosis by RT-qPCR for other viruses of the Flavivirus, Alphavirus Enterovirus genera and qPCR for Primate Erythroparvovirus 1 (B19V) species, in accordance with Ministry of Health guidelines.

RESULTS

Among the 713 cases, 78.2% tested positive for viral infections, including 48% with CHIKV viremia, 0.6% with DENV and 0.1% with ZIKV. Arboviral coinfections totaled 2.4%, including DENV-CHIKV (1.7%) and CHIKV-ZIKV (0.7%). Moreover, 8% exhibited B19V viremia. Simultaneous infections were identified in 17.5%, encompassing B19V-CHIKV (17.1%), B19V-DENV (0.1%), and B19V-ZIKV (0.3%) Triple infections were observed in 1.3% of cases with B19V-DENV-CHIKV (1%) and B19V-CHIKV-ZIKV (0.3%).

CONCLUSION

Molecular testing demonstrated high efficacy in diagnosing prevalent arboviruses and detecting multiple coinfections. This approach helps to elucidate etiologies for symptomatic cases, especially during arbovirus outbreaks, and aids comprehensive surveillance. Our findings underscore the importance of monitoring co-circulating pathogens, such as B19V, with implications for clinical management, particularly in pregnant individuals. This study enhances our understanding of arbovirus epidemiology and reinforces the critical role of molecular diagnosis in disease surveillance and control.

Can asymptomatic SARS-CoV-2 infection cause spontaneous abortion?

Aim: The probability of spontaneous abortion is known to increase (15%) in the pregnant women who develop symptomatic and even “Severe Acute Respiratory Syndrome (SARS)” due to maternal infections. It is known that the SARS-CoV-2 virus, one of these infectious agents, enters host cells by binding to angiotensin-converting enzyme 2 (ACE2). New literature data have shown the increased ACE2 receptor in the endometrium during the decidualization phase and the ability of SARS-CoV-2 to enter endometrial stromal cells through ACE2 proteins. This shows that the COVID-19 infection can cause many pathologies such as early pregnancy loss. The aim of this study is to investigate the effects of SARS-CoV-2 virus which are positive in the uterine samples on pregnancy loss. Material and Method: 13 women who had first trimester pregnancy loss were included in this cross-sectional study. None of these pregnant women had any known symptoms of SARS-CoV-2 infection. SARS-CoV-2 infection was screened in uterus and naso-oropharynx samples by real-time polymerase chain reaction (RT-PCR) test in these pregnant women. Women with positive RT-PCR results will be evaluated for pneumonia by lung tomography. It is planned to evaluate the sample taken from the naso-oropharynx in the partners of these women for SARS-CoV-2 infection by RT-PCR. In addition, in positive cases, RT-PCR was planned from the uterus and naso-oropharynx samples at 7-day intervals until the case turned negative. Results: RT-PCR test for SARS-CoV-2 was positive only in a sample taken from the uterus of one woman (7.6%). The naso-oropharyngeal sample of the same patient was negative, and the patient had no symptoms of COVID-19. No COVID-19-related lesion was observed in the lung tomography of this patient. The results of the RT-PCR test performed 7 days later with samples taken from the uterus and naso-pharynx were also negative. After the patient's positive RT-PCR result, a naso-oropharyngeal sample was taken from his partner. The RT-PCR test result for SARS-CoV-2 in the patient's partner was negative. Conclusion: The fact that the SARS-CoV-2 virus was negative in the naso-oropharyngeal sample and positive in the uterine sample in a pregnant woman who had a miscarriage suggests that the endometrium may be an entry route for the virus. These data suggest that the virus can lead to adverse pregnancy outcomes, including early pregnancy loss, even without known symptoms. A large number of studies are needed to evaluate the effects of common viruses on pregnancy beyond the expected and defined symptoms.

Cost-Effectiveness of Exome Sequencing versus Targeted Gene Panels for Prenatal Diagnosis of Fetal Effusions and Non-Immune Hydrops Fetalis

BACKGROUND

Although exome sequencing has a greater overall diagnostic yield than targeted gene panels in the evaluation of nonimmune hydrops fetalis and fetal effusions, the cost-effectiveness of this approach is not known.

OBJECTIVE

This study aimed to evaluate the costs and outcomes of targeted gene panels vs exome sequencing for prenatally diagnosed nonimmune hydrops fetalis and fetal effusions when next-generation sequencing is pursued following nondiagnostic standard nonimmune hydrops fetalis evaluations, including karyotype or chromosomal microarray.

STUDY DESIGN

A decision-analytical model was designed using TreeAge Pro to compare 10 genetic testing strategies, including a single test only (RASopathy, metabolic, or nonimmune hydrops fetalis-targeted gene panel or exome sequencing), sequential testing (RASopathy panel followed by nonimmune hydrops fetalis panel, metabolic panel followed by nonimmune hydrops fetalis panel, RASopathy panel followed by exome sequencing, metabolic panel followed by exome sequencing, and nonimmune hydrops fetalis panel followed by exome sequencing), and no additional genetic testing. Our theoretical cohort included cases with normal karyotype and/or microarray and excluded cases of alloimmunization and congenital viral infections. As nonimmune hydrops fetalis and fetal effusions can present throughout gestation, whereas pregnancy management options vary depending on gestational age, outcomes were calculated for 3 time intervals: 10 to 18, 18 to 22, and >22 weeks of gestation. The primary outcome was incremental cost per quality-adjusted life year. Additional outcomes included termination of pregnancy, stillbirth, neonatal death, and neonates born with mild, moderate, and severe or profound disease phenotypes. The cost-effectiveness threshold was $100,000 per quality-adjusted life year.

RESULTS

Among women <18 weeks of gestation, exome sequencing alone was the dominant strategy associated with the lowest costs ($221 million) and the highest quality-adjusted life years (10,288). Strategies with exome sequencing alone or as a sequential test resulted in more terminations but fewer stillbirths, neonatal deaths (NNDs), and affected infants than strategies without exome sequencing. Among women between 18 and 22 weeks of gestation, exome sequencing alone was also associated with the lowest costs ($188 million) and the highest quality-adjusted life years (8734), and similar trends were observed in pregnancy outcomes. Among patients >22 weeks of gestations, when termination was not available, exome sequencing was associated with lower costs ($300 million) and the highest quality-adjusted life years (8492). Exome sequencing was cost-effective up to a cost per test of $50,451 at <18 weeks of gestation, $50,423 at 18 to 22 weeks of gestation, and $9530 at >22 weeks of gestation. Targeted genetic panels and exome sequencing were cost-effective strategies compared with no additional genetic testing.

CONCLUSION

For cases of nonimmune hydrops fetalis and fetal effusions with nondiagnostic karyotype or microarray, next-generation sequencing was cost-effective compared with a strategy without additional genetic testing. For those that undergo next-generation sequencing, exome sequencing was the cost-effective strategy compared with all other testing strategies using targeted gene panels, leading to lower costs and fewer adverse perinatal outcomes. Exome sequencing was cost-effective in a setting without the option for pregnancy termination. These data supported the routine use of exome sequencing when next-generation sequencing is pursued for establishing a genetic diagnosis underlying otherwise unexplained nonimmune hydrops fetalis and fetal effusions.

Human parvovirus B19 infection in a pregnant patient resulting in severe hydrops, foetal death and persistent infection

Human parvovirus B19 (B19V) is the aetiological agent of erythema infectiosum. Primary infection during pregnancy can be transmitted to the foetus and cause foetal abnormalities related to depletion of erythrocyte progenitor cells, including congenital anaemia, hydrops, and foetal death. In this paper we report the detection of B19V infection in a pregnant patient, which onset occurred without appreciable signs and symptoms until she developed inappropriate contractions for gestational age and fluid loss. B19V infection resulted in severe hydrops fetalis with a fatal course for the foetus, while persisted in the mother at least 12 months after foetal death. The objective of this report is to highlight the importance of optimizing B19V diagnosis through early suspicion and testing during pregnancy. Knowing the mother’s immune status before or at the beginning of gestation can contribute, together with early diagnosis, to improve the management of patients at risk.

Potential role of viral infections in miscarriage and insights into the underlying molecular mechanisms

Intrauterine viruses can infect the decidua and placenta and cause adverse effects on the fetus during gestation. This review discusses the contribution of various viral infections to miscarriage and the molecular mechanisms by which viruses can cause devastating effects on healthy fetuses and induce miscarriage. Severe acute respiratory syndrome coronavirus 2 as newly emerged coronavirus was considered here, due to the concerns about its role during pregnancy and inducing miscarriage, as well. In this narrative review, an extensive literature search was conducted to find all studies investigating viral infections in miscarriage and their molecular mechanisms published over the past 20 years. The results of various studies investigating the roles of 20 viral infections in miscarriage are presented. Then, the mechanisms of pregnancy loss in viral infections were addressed, including alteration of trophoblast invasion and placental dysfunction, inducing excessive maternal immune response, and inducing apoptosis in the placental tissue. Viruses may cause pregnancy loss through different mechanisms and our knowledge about these mechanisms can be helpful for controlling or preventing viral infections and achieving a successful pregnancy.

Parvovirus B19 in Pregnancy: A Case Review

Parvovirus B19 has been identified as the cause of erythema infectiosum, a common childhood illness. Also known as fifth disease, this virus is highly contagious among school-age children, especially during the winter months when outbreaks within classrooms are widespread. The majority of adults have had the infection in childhood and are immune to recurrence. Approximately 40% of childbearing-age individuals, however, remain nonimmune and susceptible to infection. If acquired during pregnancy, parvovirus B19 infection can have devastating fetal consequences, especially if contracted in the second trimester. Vertical transmission of parvovirus B19 occurs more readily during this gestational period, and fetal loss rates of 8% to 17% have been reported as a result of severe fetal anemia and hydrops fetalis. Unfortunately, adults with parvovirus B19 infection are often asymptomatic and do not exhibit the classic slapped-cheek rash seen in childhood. More commonly, adults will exhibit atypical symptoms such as joint arthralgias. Maternal history of direct exposure to a confirmed case within the family or the presence of atypical symptoms warrants serum antibody screening. Although the presence of immunoglobulin G confirms immunity, any immunoglobulin M positivity will require ongoing fetal surveillance for evidence of fetal anemia and hydrops fetalis. Serial ultrasound imaging for 8 to 12 weeks with Doppler measurements of the peak systolic velocity in the middle cerebral artery are the mainstays of fetal monitoring. Referral to a maternal-fetal medicine specialist with experience in fetal blood sampling and intrauterine transfusion is recommended for any cases of hydrops fetalis or if a concern for severe fetal anemia exists.

Fetal, neonatal, and infant outcomes associated with maternal Zika virus infection during pregnancy: A systematic review and meta-analysis

The occurrence of fetal and neonatal disorders in pregnant women with Zika virus infection in the literature is not consistent. This study aims to estimate the prevalence rate of these disorders in fetuses/neonates of pregnant women with confirmed or probable infection by Zika virus. A systematic review with meta-analysis was conducted in November 2020. Cohort studies that contained primary data on the prevalence of unfavorable outcomes in fetuses or neonates of women with confirmed or probable Zika virus infection during pregnancy were included. A total of 21 cohort studies were included, with a total of 35,568 pregnant women. The meta-analysis showed that central nervous system abnormalities had the highest prevalence ratio of 0.06 (95% CI 0.03-0.09). Intracranial calcifications had a prevalence ratio of 0.01 (95% CI 0.01-0.02), and ventriculomegaly 0.01 (95% CI 0.01-0.02). The prevalence ratio of microcephaly was 0.03 (95% CI 0.02-0.05), fetal loss (miscarriage and stillbirth) was 0.04 (95% CI 0.02-0.06), Small for Gestational Age was 0.04 (95% CI 0.00-0,09), Low Birth Weight was 0.05 (95% CI 0.03-0.08) and Prematurity was 0.07 (95% CI 0.04-0.10). The positivity in RT-PCR for ZIKV performed in neonates born to infected mothers during pregnancy was 0.25 (95% CI 0.06-0.44). We also performed the meta-analysis of meta-analysis for microcephaly with the prevalence ratios from other two previously systematic reviews: 0.03 (95% CI 0.00-0.25). Our results contribute to measuring the impact of Zika virus infection during pregnancy on children's health. The continuous knowledge of this magnitude is essential for the implementation development of health initiatives and programs, in addition to promoting disease prevention, especially in the development of a vaccine for Zika virus. PROSPERO protocol registration: http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42019125543.

Immune Regulation, Maternal Infection, Vaccination, and Pregnancy Outcome

About 12.5% of all maternal deaths in the United States are due to infectious causes. This proportion, although stable during the past three decades, represents an increase in infectious causes of mortality, as the overall mortality rate in U.S. pregnant women had increased steadily during that same period. During healthy pregnancies, a delicate immunological balance-in which a mother's immune system tolerates the semi-allogeneic fetus yet maintains immune competency against infectious agents-is achieved and maintained. This immunological paradigm, however, results in increased susceptibility to infectious diseases during pregnancy, particularly in later stages and during the early postpartum period. The inflammatory process induced by these infectious insults, as well as some noninfectious insults, occurring during pregnancy can disrupt this carefully achieved balance and, in turn, lead to a state of rampant inflammation, immune activation, and dysregulation with deleterious health outcomes for the mother and fetus. Elucidating mechanisms contributing to the disruption of this immunologic homeostasis, and its disruption by infectious pathogens, might offer opportunities for interventions to reduce maternal and fetal morbidity and mortality.

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.

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.

Multidrug-resistant tuberculosis during pregnancy and adverse birth outcomes: a systematic review and meta-analysis

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is a major global public health concern. However, there is a dearth of literature on whether MDR-TB and its medications impact maternal and perinatal outcomes, and when such evidence exists the findings are conflicting.

OBJECTIVES

This systematic review and meta-analysis aimed to examine the impact of MDR-TB and its medications during pregnancy on maternal and perinatal outcomes.

SEARCH STRATEGY

PubMed, Scopus and Web of Science databases were searched from earliest to February 2020.

SELECTION CRITERIA

Records were screened based on pre-defined selection criteria and assessed for quality by two independent reviewers.

DATA COLLECTION AND ANALYSIS

A meta-analysis was performed using the random effects model to calculate pooled prevalence for each outcome.

MAIN RESULTS

Of the 72 records identified, 12 were included in the systematic review and meta-analysis, consisting of 174 pregnant women with MDR-TB and 110 adverse outcomes. Maternal death, pregnancy loss, preterm birth and low birthweight were the most common maternal and perinatal adverse outcomes reported in the studies. The overall pooled prevalence was 7.5% (95% CI 3.2-12.8) for maternal death, 10.6% (95% CI 6.0-16.3) for pregnancy loss, 12.9% (95% CI 0.0-38.0) for preterm birth and 23.7% (95% CI 17.0-31.0) for low birthweight.

CONCLUSIONS

The findings suggest that MDR-TB is associated with a high risk of adverse maternal and perinatal outcomes, but these should be interpreted cautiously because the evidence is largely preliminary. Adequately powered prospective cohort studies are urgently required to corroborate these findings.

TWEETABLE ABSTRACT

Multidrug-resistant tuberculosis may increase the risk of adverse maternal and perinatal outcomes.

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.

Parvovirus B19 DNAemia in pregnant women in relation to perinatal death: A nested case-control study within a large population-based pregnancy cohort

INTRODUCTION

Parvovirus B19 (B19V) is the infectious cause of exanthema infectiosum. In Europe around 40% of pregnant women are susceptible to infection. Having small children at home is the main risk factor for contracting an infection during pregnancy. The association between B19V-infection and perinatal death is not yet settled. The aims of the study were to estimate the association between maternal parvovirus B19 infection in pregnancy and perinatal death, and to assess the significance of a positive B19V PCR in pregnancy.

MATERIAL AND METHODS

The study population consists of women included in the Norwegian Mother and Child Cohort Study, a prospective population-based pregnancy cohort of nearly 100 000 women. Blood samples were obtained during weeks 17-18 in pregnancy (M1), at birth, and in umbilical cord blood. Within participants in the pregnancy cohort, 138 cases of perinatal death and 1350 controls with live-born children were included in a nested case-control study. Samples were analyzed with B19V serology and B19V PCR according to a predefined test algorithm. For cases, medical records and laboratory results from hospitals were combined with the results of B19V serology and PCR. The reported causes of perinatal death were categorized using the classification system: Causes Of Death and Associated Conditions (CODAC).

RESULTS

The B19V seroconversion rates were 9.8% for cases and 6.8% for control mothers. The odds ratio for maternal B19V infection in cases compared with controls was 1.28 (95% CI 0.35-4.70), adjusted for age, parity, body mass index and tobacco use. B19V-PCR-positive samples were detected at weeks 17-18 of gestation in both cases and controls. The proportion of positive samples was similar in cases and controls, 24% and 28.2%, respectively. Mothers with PCR-positive M1 samples transmitted B19V vertically in 9.1% of cases and in 11.9% of the controls. Of all perinatal deaths, 53% were attributed to placental pathology or unknown causes.

CONCLUSIONS

B19V PCR positivity was high and similar in both cases and controls. In our study B19V DNAemia was not seen to be associated with fatal outcome of pregnancy. The clinical significance of B19V DNA detection during pregnancy is uncertain. Caution is needed when diagnosing a B19V infection based only on B19V DNAemia.

Key Infections in the Placenta

Congenital infections are an important cause of morbidity and mortality worldwide, especially in low-income settings. This review discusses the main pathways of infections and associated adverse maternal and fetal outcomes, considering the TORCH pathogens, including Zika virus; the acronym stands for Toxoplasma gondii infection, other (Listeria monocytogenes, Treponema pallidum, and parvovirus B19, among others, including Zika virus), rubella virus, cytomegalovirus, and herpes simplex viruses type 1 and type 2.

Advances in the Development of Antiviral Strategies against Parvovirus B19

Parvovirus B19 (B19V) is a human pathogenic virus, responsible for an ample range of clinical manifestations. Infections are usually mild, self-limiting, and controlled by the development of a specific immune response, but in many cases clinical situations can be more complex and require therapy. Presently available treatments are only supportive, symptomatic, or unspecific, such as administration of intravenous immunoglobulins, and often of limited efficacy. The development of antiviral strategies against B19V should be considered of highest relevance for increasing the available options for more specific and effective therapeutic treatments. This field of research has been explored in recent years, registering some achievements as well as interesting future perspectives. In addition to immunoglobulins, some compounds have been shown to possess inhibitory activity against B19V. Hydroxyurea is an antiproliferative drug used in the treatment of sickle-cell disease that also possesses inhibitory activity against B19V. The nucleotide analogues Cidofovir and its lipid conjugate Brincidofovir are broad-range antivirals mostly active against dsDNA viruses, which showed an antiviral activity also against B19V. Newly synthesized coumarin derivatives offer possibilities for the development of molecules with antiviral activity. Identification of some flavonoid molecules, with direct inhibitory activity against the viral non-structural (NS) protein, indicates a possible line of development for direct antiviral agents. Continuing research in the field, leading to better knowledge of the viral lifecycle and a precise understanding of virus–cell interactions, will offer novel opportunities for developing more efficient, targeted antiviral agents, which can be translated into available therapeutic options.