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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., (© 2020 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics (NFOG).)

Human parvovirus B19 (B19V) is well known for its infectivity. However, the risk for communicability to previously unexposed healthcare professionals is controversial. We report here a small outbreak of B19V infection among physicians and family members in an adult rheumatology practice that occurred after providing care for a patient with B19V arthropathy. As B19V-infected patients who demonstrate findings of erythema infectiosum or viral arthritis are generally beyond the period of transmissability, strict handwashing and droplet precautions remain imperative when there is contact with potentially pre-symptomatic family members.

Objective : In this systematic review, we aimed to summarize the evidence on the association between being a daycare educator working with children and the possible increased risk of parvovirus B19 infection compared to the general population. Methods : The Medline and Embase databases were searched using a defined search to find studies published since 2000. Two reviewers evaluated the search hits using predefined inclusion and exclusion criteria. The resulting studies were extracted and were assessed in eight domains of bias. A pooled relative risk (RR) of parvovirus infection for daycare workers compared to the general population was calculated. Results : After evaluating the 7781 search hits and manual search, four methodologically-adequate studies were identified: three cross-sectional studies and one retrospective cohort study. Of the three studies investigating the risk of infection, one evaluated parvovirus B19 seroconversion rates for daycare workers. There was an indication for an increased risk for daycare workers compared to the unexposed population (RR = 1.12, 95% CI 0.98-1.27) using prevalence estimators. Furthermore, daycare workers had a higher seroconversion rate compared to the unexposed population (RR = 2.63, 95% 1.27-5.45) in the low risk of bias study. Conclusions : Our findings suggest a higher risk of parvovirus B19 infection for daycare workers compared to an unexposed comparison population, which necessitate preventative efforts. Considering the underestimation of the occupational seroconversion risk by prevalence-based estimators, parvovirus B19 infections among daycare workers might mostly be occupationally acquired., Competing Interests: The authors declare no conflict of interest.

Parvovirus B19 (PB19) is an important human pathogen that results in a wide spectrum of clinical outcomes, from mild, self-limiting erythema infectiosum in immunocompetent children and arthralgia in adults to lethal cytopenia in immunocompromised patients and intrauterine fetal death. However, there have been few reports of PB19 infection in neonates or young infants (aged 28-90 days), and no previous reports contained descriptions of PB19 infection as a cause of sepsislike syndrome in this age group. We report a case of sepsislike syndrome caused by PB19 infection in a 56-day-old infant whose mother had polyarthralgia at the time of his admission. PB19 infection was diagnosed on the basis of positive polymerase chain reaction results for PB19 DNA in the serum and cerebrospinal fluid. Positive immunoglobulin M and negative immunoglobulin G for PB19 suggested acute infection. He was admitted to the ICU because of poor peripheral circulation, but fully recovered without antibiotic administration. After excluding other possible pathogens, PB19 should be suspected as a cause of sepsislike syndrome in young infants, especially those who have close contact with PB19-infected individuals., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2018 by the American Academy of Pediatrics.)

Background: Congenital cytomegalovirus (cCMV) infection is the most prevalent congenital infection acquired worldwide, with higher incidence in developing countries and among HIV-exposed children. Less is known regarding vertical transmission of parvovirus B19 (B19V) and enterovirus (EV). We aimed to assess the prevalence of CMV, B19V and EV vertical transmission and compare results of screening of congenital CMV obtained from two different specimens in a semirural Mozambican maternity., Methods: A cross sectional study was conducted among pregnant mothers attending Manhiça District Hospital upon delivery. Information on maternal risk factors was ascertained. Dried umbilical cord (DUC) samples were collected in filter paper for CMV, B19V and EV detection by real-time polymerase chain reaction (RT-PCR), and nasopharyngeal aspirates (NPA) to test for CMV by RT-PCR. Maternal blood samples and placental biopsy samples were also obtained to investigate CMV maternal serology, HIV status and immunopathology., Results: From September 2014 to January 2015, 118 mothers/newborn pairs were recruited. Prevalence of maternal HIV infection was 31.4% (37/118). CMV RT-PCR was positive in 3/115 (2.6%) of DUC samples and in 3/96 (6.3%) of NPA samples obtained from neonates. The concordance of the RT-PCR assay through DUC with their correspondent NPA sample was moderate (Kappa = 0.42 and p<0.001. No differences on cCMV prevalence were found among HIV-exposed and unexposed. All (100%) mothers were seropositive for CMV IgG. RT-PCR of EV and B19V in DUC were both negative in all screened cases. No histological specific findings were found in placental tissues. No risk factors associated to vertical transmission of these viral infections were found., Conclusions: This study indicates the significant occurrence of vertical transmission of CMV in southern Mozambique. Larger studies are needed to evaluate the true burden, clinical relevance and consequences of congenital infections with such pathogens in resource-constrained settings.

Persistent parvovirus B19 (PVB) infection has been reported sporadically in immunocompromised patients including hematopoietic stem cell and solid organ transplant recipients. However, the pathogenesis of persistent infection has yet to be fully elucidated. We report here a patient with multiple myeloma developing red cell aplasia during the hematopoietic recovery after allogeneic hematopoietic stem cell transplantation (HSCT) caused by PVB. The patient had already had PVB viremia before transplantation and remained asymptomatic. The route of PVB transmission was considered to be direct contact with the patient's family member with primary PVB infection 1 month before transplantation. Treatment with intravenous immunoglobulin resulted in prompt resolution of anemia. These findings suggest that monitoring of PVB DNA is recommended for patients undergoing HSCT and having contact with individuals with documented PVB infection, even if they are asymptomatic., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The prevalence of postinfectious glomerulonephritis has decreased in most developed countries. We report the case of a previously healthy, immunocompetent 65-year-old woman who developed acute glomerulonephritis associated with human parvovirus B19 infection. She was referred by her primary care physician for suspected congestive heart failure but she had an elevated creatinine level and an abnormal urinalysis. Renal biopsy showed diffuse endocapillary proliferative glomerulonephritis. After biopsy, we learned that she had been in frequent contact with her grandson who had been diagnosed with erythema infectiosum. Her human parvovirus B19 serum IgM titer was elevated at 3.50, indicating current infection.

After a steep monotone rise with age, the seroprevalence profiles for human parvovirus B19 (PVB19) display a decrease or plateau between the ages of 20 and 40, in each of 5 European countries. We investigate whether this phenomenon is induced by waning antibodies for PVB19 and, if this is the case, whether secondary infections are plausible, or whether boosting may occur. Several immunological scenarios are tested for PVB19 by fitting different compartmental dynamic transmission models to serological data using data on social contact patterns. The social contact approach has already been shown informative to estimate transmission rates and the basic reproduction number for infections transmitted predominantly through nonsexual social contacts. Our results show that for 4 countries, model selection criteria favor the scenarios allowing for waning immunity at an age-specific rate over the assumption of lifelong immunity, assuming that the transmission rates are directly proportional to the contact rates. Different views on the evolution of the immune response to PVB19 infection lead to altered estimates of the age-specific force of infection and the basic reproduction number. The scenarios which allow for multiple infections during one lifetime predict a higher frequency of PVB19 infection in pregnant women and of associated fetal deaths. When prevaccination serological data are available, the framework developed in this paper could prove worthwhile to investigate these different scenarios for other infections as well, such as cytomegalovirus.

Question: One of my pregnant patients came for a routine prenatal visit at 20 weeks' gestation. Near the end of the consultation, she asked me about "slapped cheek" disease and pregnancy, as her son had been diagnosed with fifth disease the previous week. What is the current guideline for pregnant women exposed to parvovirus B19?, Answer: The rate of vertical transmission during maternal parvovirus B19 infection is estimated at 33%, with fetal complications occurring in 3% of infected women. Fetal complications comprising hemolysis, anemia, and nonimmune hydrops fetalis and fetal loss are more frequent when maternal infection occurs before 20 weeks of gestation. The first step in the management of this patient would be to obtain immunoglobulin (Ig) M and IgG titres against parvovirus to evaluate if the patient has had previous immunity against the disease. If results are negative for IgG but positive for IgM (ie, primary infection), this patient would need close obstetrical monitoring for the following weeks, including serial ultrasounds to rule out fetal anemia and hydrops fetalis.

Background: Although the main transmission pathway of parvovirus B19 (B19) is typically via the respiratory route, several transfusion-transmitted infections have been reported. To increase blood safety, all blood donations to our blood donor service have been screened by a B19 minipool real-time nucleic acid testing (NAT) since April 2000. Additional customers have been screened since the summer of 2003., Study Design and Methods: In total, 2.8 million donations from Germany and Austria were screened for B19 by real-time minipool NAT. A subgroup of 50 B19 DNA-positive donors was screened for B19 immunoglobulin G (IgG) and IgM antibodies and B19 DNA over a 6-month period. Results were compared to those of 100 B19 DNA-negative donors., Results: Data accumulated over the past 6 years indicate a high incidence period from May 2004 to January 2006. In total, the incidence was 12.7 and 261.5 per 100,000 donations with high virus loads equal to or above 10(5) and below 10(5) IU per mL, respectively. Median virus concentration in the case group was 4.85 x 10(7) IU per mL at Time Point T0 and was reduced to 4 x 10(2) IU per mL at the time of the next donation (3 months later). Neutralizing antibodies (VP2) were detected in all donations if virus load was reduced to less than 10(5) IU per mL., Conclusion: The release of B19 DNA-positive blood products with a concentration of less than 105 IU per mL is thought to be safe due to the high level of neutralizing VP2 antibodies and is currently examined in a donor recipient infectivity study. In contrast, blood products with a high B19 DNA concentration (> or =10(5) IU/mL), some of which did not contain neutralizing antibodies, were discarded to protect at risk individuals.

Background: Blood donor parvovirus B19 DNA prevalence with sensitive nucleic acid test assays has recently been demonstrated to be higher than that found with assays designed to detect high viral titers in the plasma manufacturing sector., Study Design and Methods: Stored plasma aliquots from 5020 donations collected between 2000 and 2003 at seven US blood centers were tested. Testing was performed with a real-time B19 DNA polymerase chain reaction (PCR; TaqMan, Applied Biosystems) assay with a 50 percent limit of detection (LOD) of 1.6 IU per mL (95% confidence interval [CI], 1.2-2.1 IU/mL) and a 95 percent LOD of 16.5 IU per mL (95% CI, 10.6-33.9 IU/mL). Confirmation and quantitation of B19 DNA was accomplished by retesting of two additional subaliquots. Confirmed-positive specimens were tested for the presence of anti-B19 immunoglobulin M (IgM) and IgG with FDA-licensed assays., Results: B19 DNA prevalence was 0.88 percent (95% CI, 0.64%-1.2%). Among the 23 donations with B19 DNA titers of at least 20 IU per mL, the median DNA concentration was 105 IU per mL with an interquartile range of 42 to 481 IU per mL; the highest value was 1869 IU per mL. All B19 DNA-positive donations were positive for the presence of IgG and 10 (23%) were also positive for the presence of IgM; IgM seropositivity was associated with increasing DNA levels (p = 0.0013)., Conclusion: Low-level B19 DNA was detected in nearly 1 percent of donations. The 23 percent of DNA-positive donations with both IgM and IgG B19 antibody most likely represent acute resolving infection, whereas those with IgG but no IgM are most consistent with a more chronic and possibly persistent phase of B19 infection.

Background: B19 virus (B19V) is a human pathogen frequently present in blood specimens. Transmission of the virus occurs mainly via the respiratory route, but it has also been shown to occur through the administration of contaminated plasma-derived products. Parvoviridae are highly resistant to physicochemical treatments; however, B19V is more vulnerable than the rest of parvoviruses. The molecular mechanism governing the inactivation of B19V and the reason for its higher vulnerability remain unknown., Study Design and Methods: After inactivation of B19V by wet heat and low pH, the integrity of the viral capsid was examined by immunoprecipitation with two monoclonal antibodies directed to the N-terminal of VP1 and to a conformational epitope in VP2. The accessibility of the viral DNA was quantitatively analyzed by a hybridization-extension assay and by nuclease treatment., Results: The integrity of the viral particles was maintained during the inactivation procedure; however, the capsids became totally depleted of viral DNA. The DNA-depleted capsids, although not infectious, were able to attach to target cells. Comparison studies with other members of the Parvoviridae family revealed a remarkable instability of B19V DNA in its encapsidated state., Conclusion: Inactivation of B19V by heat or low pH is not mediated by capsid disintegration but by the conversion of the infectious virions into DNA-depleted capsids. The high instability of the viral DNA in its encapsidated state is an exclusive feature of B19V, which explains its lower resistance to inactivation treatments.

Pregnant women who report possible exposure to a viral illness can present a clinical predicament for obstetric providers. Although some viruses are benign in pregnancy, others can have serious consequences. Parvovirus B19, the causative agent of fifth disease, is one of the more serious of the common viruses. Understanding the pathophysiology and appropriate testing for parvovirus will help providers better counsel their patients.

Background: Human parvovirus B19 (B19) is a widely distributed infectious agent, which causes a variety of illnesses including erythema infectiosum (fifth disease) especially in children, arthritis, aplastic crisis, and hydrops fetalis. B19 can be transmitted from asymptomatic blood donors to recipients of their blood components. Fifth disease has been reported in patients receiving red blood cells, platelets, solvent/detergent-treated plasma, and clotting factor concentrates., Study Design and Methods: A new B19-specific Light Cycler (LC) reverse transcription-polymerase chain reaction (RT-PCR) infectivity assay was developed for quantitative analysis of the infectivity of B19 in virus validation studies. The cycling conditions and the primers of the new assay were designed to amplify spliced RNA forms but not precursor RNA or B19 genome. One 50 percent infectious dose, determined on UT7/Epo-S1 cells of low passage, equaled 3.74+/-0.1 log international units of B19 DNA., Results: The efficiency of the dry-heat process (100 degrees C) on inactivation of B19 spiked and lyophilized with fibrinogen, a major component of the clotting factor concentrate and hemostatic dressing products, was investigated by use of B19-specific LC RT-PCR infectivity assay. At 1.3 to 1.7 percent residual moisture of fibrinogen, the infectivity of B19 was reduced dramatically by 3.3 to 5.1 log for 1 and 2 hours of dry-heat treatment, respectively. B19 infectivity was reduced 1.5, 2.8, and 3.8 log for 1, 2, and 3 hours of dry-heat treatment, respectively, at 0.5 to 0.7 percent residual moisture level., Conclusion: These findings suggest that level of residual moisture of lyophilized fibrinogen with B19 spike correlated with a different resistance of B19 to dry-heat treatment, and that low moisture may stabilize virus against heat.

Background and Objectives: Human parvovirus (erythrovirus) B19 is recognized as a major contaminant of blood and blood products. To reduce the risk of contamination, plasma-pool screening and exclusion of highly viraemic donations are recommended. The objectives of this study were to estimate the prevalence of B19 DNA in our blood-donor population, to determine the appropriate pool size to be tested (taking into account parameters such as prevalence, viral load, test sensitivity, and the efficacy of inactivation procedures), and to correlate viral loads with the serological status of donors as regards antibodies against different viral proteins., Materials and Methods: Pools of different sizes were tested for B19, using a sensitive nested polymerase chain reaction (PCR) as well as an simple, un-nested, less sensitive PCR. Positive pools were resolved to the level of individual donations, and the viral load and serological markers were determined., Results: Of 16,859 donations, 27 (one of 625) were found to be B19 DNA positive, with viral loads ranging from 10(2) to > 10(7) IU/ml. Twenty-five of the positive donations were tested for VP-specific anti-B19 antibodies, and eight (32%) were negative for both immunoglobulin (Ig)M and IgG. They were probably collected in the preseroconversion window period or from chronic carriers without detectable antibodies. We regarded the seven (28%) IgM-positive donors as being in the early phase of infection. The remaining 10 (40%) IgM-negative, IgG-positive donors were probably carriers of persistent infection (i.e. PCR positive despite the presence of IgG antibodies), as suggested by their low viral loads (< 10(4) IU/ml). Fifteen out of 36 major pools contained one or more contaminated donations. Among these, 12 tested positive by nested PCR and only three by un-nested PCR, this reflecting a viral load of > 10(4) IU/ml., Conclusions: By testing all donations as pools of 480 by un-nested PCR, and resolving positive pools to identify the responsible donations, it is possible to ensure that the viral load in fractionation pools (5000 donations) remains < 10(3) IU/ml, compatible with the efficacy of inactivation procedures and complying with Food and Drug Administration (FDA) recommendations.

Background and Objectives: To date there has been no published report on a systematic evaluation of the heat sensitivity of human parvovirus B19 (B19) and the related safety of the plasma-derived fractionated products. In this study, we examined the heat sensitivity of B19 by using the infectivity assay with cultured cells., Materials and Methods: The heat sensitivity of B19 was examined by measuring the reduction in viral infectivity titres after heating liquid containing B19 at 60 degrees C. Viral infectivity was assayed by detection of viral antigens or viral mRNA in infected cells. As a control, canine parvovirus (CPV) was also heat-treated., Results: B19 displayed quite different inactivation kinetics to CPV when both were heated in liquid at 60 degrees C. In sharp contrast to the latter, B19 was rapidly inactivated within 1 h when the virus was suspended in 5% or 25% human serum albumin solution, phosphate-buffered saline, or complete medium. However, B19 appeared to be resistant to heat inactivation in liquid containing 60% sucrose., Conclusions: The heat sensitivity of B19 in liquid was clearly different from that of CPV. Significantly, the efficiency to inactivate B19 and reduce its infectivity following heating in liquid was mainly affected by the composition of the solutions used for virus suspension.

Some infections are more serious in pregnant than non-pregnant women because of the potential for vertical transmission to the fetus or infant (eg, varicella, rubella, cytomegalovirus infection, toxoplasmosis and listeriosis). Pre-pregnancy or routine antenatal screening for presence of, or susceptibility to, some of these infections and appropriate management can prevent adverse fetal or perinatal outcomes; screening should include rubella IgG, hepatitis B surface antigen, serological tests for syphilis and HIV antibody. If certain other vertically transmissible infections are suspected because of a positive antenatal test result, confirmatory tests for maternal and, if indicated, fetal infection are essential before intervention is considered (eg, cytomegalovirus infection). For some vertically transmissible infections that are not readily preventable, appropriate management of maternal infection can reduce fetal damage (eg, toxoplasmosis).

Introduction: Acute parvovirus B19 infection induces a transient inhibition of erythroid cell formation, which may induce an erythroblastopenia crisis in patients suffering from chronic hemolytic anemia., Exegesis: We report here an exceptional observation of acute erythroblastopenia crisis with good outcome, occurring at the same time in a mother and her son, both suffering from hereditary spherocytosis. Diagnosis of parvovirus infection is based on detection of serum parvovirus B19-specific immunoglobulin M antibodies in the mother and her son and by the positivity of parvovirus B19 DNA detected by PCR in serum in the mother. Outcome was good, with the end of the erythroblastopenia crisis obtained 7 to 10 days later, but requiring blood transfusion in the mother., Conclusion: Our observation is a reminder that the contagiosity of parvovirus B19 is high in household contacts and that protection of family members should rapidly be considered in hereditary spherocytosis.

We describe a case of symptomatic parvovirus B19 infection transmitted by bone marrow (BM). The infection caused prolonged anaemia, thrombocytopenia, arthralgia and erythema infectiosum in a 16-year-old girl with acute myeloid leukaemia receiving a BM transplant (BMT). The BM donor was a 19-year-old asymptomatic brother who had parvovirus B19 viraemia at the time of BM harvest. Sequencing of the VP2 gene from the patient and the donor showed a perfect match of DNA sequences, confirming the mode of transmission. Parvovirus B19 represents a potential complicating factor in patients undergoing BMT, but screening by polymerase chain reaction (PCR) of donor BM may reduce the risk of infection.

Interventions for parvovirus B19 infection need to balance the low risk of infection at a population level with the potential for serious adverse outcome for particular groups, notably the fetus, people with haemoglobinopathies and the immunocompromised. This guidance aims to assist the local decision-making process to be as evidence-based as the available evidence allows.

Context: Parvovirus B19 infection during pregnancy has been associated with fetal death. However, the incidence of and risk factors for infection in pregnant women have not been well studied., Objectives: To estimate a pregnant woman's risk of infection with parvovirus B19 in epidemic and endemic situations and to study risk factors for infection., Design: Population-based cohort study conducted between November 1992 and June 1994., Setting: Three regions in Denmark., Participants: A total of 30946 pregnant women from a consecutive and population-based screening., Main Outcome Measures: Specific IgG antibodies in serum samples obtained in the first trimester of pregnancy and from the newborn infant to assess past infection and seroconversion. Information on family structure, educational background, socioeconomic status, and pregnancy outcome was obtained from national registers., Results: Based on 30 946 serum samples, 65.0% of pregnant women had evidence of past infection. Annual seroconversion rates among susceptible women during endemic and epidemic periods were 1.5% (95% confidence interval [CI], 0.2%-1.9%) and 13.0% (95% CI, 8.7%-23.1 %), respectively. Baseline seropositivity was significantly correlated with increasing number of siblings, having a sibling of the same age, number of own children, and occupational exposure to children. Risk of acute infection increased with the number of children in the household as follows: 0 children odds ratio (OR), 1 (reference); 1 child OR, 3.17 (95% CI, 2.24-4.49); 2 children OR, 5.47 (95% CI, 3.55-8.45); 3 or more children OR, 7.54 (95% CI, 3.80-14.94). Having children aged 6 to 7 years resulted in the highest rate of seroconversion among mothers (6.8%; OR, 4.07; 95% CI, 1.89-8.73). Compared with other pregnant women, nursery school teachers had a 3-fold increased risk of acute infection (OR, 3.09; 95% CI, 1.62-5.89). Population-attributable risk of seroconversion was 55.4% for number of own children and 6.0% for occupational exposure., Conclusions: The risk of infection is high for susceptible pregnant women during epidemics and associated with the level of contact with children. Nursery school teachers have the highest occupational risk, but most infections seem to be the result of exposure to the woman's own children.

Background and Objectives: Human parvovirus B19 (B19 virus) can be transmitted through blood transfusion and plasma-derived products. In a previous report, we utilized the simple hemagglutination method based on the interaction between the B19 virus and P antigen on human erythrocytes in order to screen the blood donors. We called this method receptor-mediated hemagglutination (RHA) [Lancet 1995;346:1237-1238]. In this paper, we report on a large-scale screening of the B19 virus by RHA and discuss the results., Materials and Methods: Donor sera from September 1995 to March 1997 and seroconversion panels were enrolled. Donor sera were examined by RHA for large-scale screening. The positive sera in the first screening were then further investigated by the RHA inhibition test, countercurrent immunoelectrophoresis (CIE), an enzyme-linked immunosorbent assay, and polymerase chain reaction (PCR). We also evaluated the infectivity and neutralizing activity of various kinds of sera by the erythroid colony forming unit (CFU-e) assay. To examine the detection limits of the B19 virus by RHA, B19-viremic sera were purified by sucrose gradient ultracentrifugation., Results: Among 257,710 sera specimens, 293 sera (0.11%) gave a positive reaction in the first screening using RHA. Out of these 293 sera specimens, 31 were positive for PCR, of which 28 were also RHA inhibition-positive, and 25 of the 28 CIE-positive. In the CFU-e injury assay, all the RHA inhibition (+) sera showed a decrease in the number of erythroid colonies. The RHA inhibition (-) PCR (+) B19 antibody (+) sera did not affect the erythroid colony formation and protected CFU-e from injury by the B19 virus. By measuring the amount of purified B19 protein and its RHA titer, the detection limit of the B19 virus by RHA was calculated to the 0.37+/-0.03 ng/ml., Conclusion: These results suggest that the RHA(+) RHA inhibition (+) sera were infectious in vitro. The combination of RHA and the RHA inhibition test is considered to be useful for the large-scale screening of infectious B19 virus in blood donors with high specificity.

Objective: To define the intrauterine viral transmission rate during primary maternal parvovirus B19 infection and identify factors that may influence this rate., Methods: Forty-three pregnant women at two medical centers were identified with a primary B19 infection and followed to delivery. At delivery maternal and infant (umbilical cord) blood was obtained for B19 serologic and virologic PCR testing., Results: All of the women delivered healthy infants at term and none was hydropic. Overall 22 (51%) of the 43 infants had some evidence of a congenital B19 infection. B19-specific IgM was detected in 11 infants at delivery, B19 IgA was detected in 10 and B19 DNA was detectable by PCR in 11 infants. One infant was negative at birth but became positive for IgM, IgA and PCR at 6 weeks of age. No association was found between the likelihood of intrauterine infection and: maternal age; symptomatic maternal infection; method of delivery; maternal IgG titer at delivery; maternal IgG avidity at delivery; or maternal viremia at delivery. Intrauterine infection was associated with maternal IgM positivity at delivery; this association may have been a result of maternal infection occurring later in gestation., Conclusion: Although the incidence of intrauterine hydrops and fetal demise after maternal infection is low, there is a high rate of intrauterine viral infection that occurs throughout gestation and yields newborns who, although infected in utero, are asymptomatic at birth.

This case report of the sequential presentation of parvovirus B19 in a family describes a 38-year-old woman initially presenting with 'gloves and socks' syndrome, along with her husband and five children who were also affected. A high clinical attack rate with prolonged illness and variable clinical presentations was demonstrated, including polyarthritis, erythema infectiosum and symptoms of a respiratory tract infection. In addition, the range of syndromes and clinical features of parvovirus B19 are presented.

A report is presented of a patient with neonatal erythema infectiosum who developed petechiae, transient thrombocytopenia and transient cardiac failure due to transplacental transmission of human parvovirus B19 (HPV B19) infection. It is suggested that the thrombocytopenia was caused by platelet-associated IgG produced by the patient, and that the cardiac failure may have been caused by direct entry of HPV B19 into the cardiac tissue.

This article summarizes new information on the natural history of maternal varicella and maternal parvovirus B19. Controversies in the therapy of respiratory syncytial virus are presented. Prophylactic and therapeutic immunotherapy of neonatal enteroviral disease are reviewed.

During an outbreak of parvovirus B19 infection among four related families at least 70% of the household contacts, including a woman at the 33rd week of pregnancy, became infected. Twins were born at the 39th week of pregnancy, both with B19 infection. B19 DNA was detected in their sera by a nested PCR, anti-B19 IgM was detectable only by an immunofluorescence assay, and low levels of maternal anti-B19 IgG were demonstrable by an immunoenzymatic test in the serum of both children. All the haematological parameters were normal at birth and 6 months later, when B19 DNA and anti-B19 antibody were no longer detectable in serum samples. This observation emphasizes the high risk of B19 infection among household contacts and the possibility of a favourable outcome of the foetal infection, possibly related to infection late in the pregnancy.

Human parvovirus B19 and cytomegalovirus (CMV) are two common viruses that can have significant and devastating effects on a fetus. Maternal infection may lead to vertical transmission of the virus to the fetus. Parvovirus infection in the fetus may cause miscarriage, nonimmune hydrops, or demise. Fetal CMV infection can cause a number of problems, including nonimmune hydrops and neurosensory disabilities. Nurses who are knowledgeable about possible viral effects during pregnancy can collaborate in the management of these patients, particularly in the areas of patient assessment, education, and support.

Many patients with haemophilia are infected with viruses, due to treatment with blood products--particularly from large pool clotting factor concentrates before 1985. AIDS in haemophilic patients was first described in 1982 and it has significantly reduced the life expectancy of these patients. Although no new sero-conversions have occurred since 1986, management of HIV in haemophilia remains a clinical challenge. Transfusion-associated hepatitis was recognized in 1943, and it is now an important complication of haemophilia treatment. Vaccination against HAV is recommended. Intensively-treated older haemophilic patients usually have serological evidence of HBV infection. HBV transmission has been stopped, but hepatitis B vaccination is still practised, because HDV requires HBV for propagation. Many patients are infected with HCV: before 1985 almost all patients who received clotting factor concentrate developed non-A, non-B hepatitis, now recognized as HCV. Treatment strategies are being developed for HCV in haemophilic patients. Parvo virus can be transmitted by clotting factor concentrate; it is very resistant to sterilization processes, transmission causing severe illness even in immuno-competent individuals. New blood-borne viruses responsible for sero-negative hepatitis include: GBV-A, B and C, and HGV. Although there is no link between CJD and haemophilia, there is concern about possible blood product transmission.

The risk of acquiring diseases from transfusion of blood and blood products is well recognized and the issue of parvovirus in haemophiliacs is not a new one. We report two patients with haemophilia acquiring iatrogenic parvovirus B19 infection, resulting in life-threatening sepsis in one, and immunocompetent adult. Over the last 10 years there has been great progress in manufacturing safer products with regard to enveloped viruses such as HIV, hepatitis B and C. A recent outbreak across Europe of hepatitis A in haemophiliacs treated with plasma-derived factor VII concentrates has made haemophilic treaters concerned about the known (parvovirus B19 and hepatitis A) and the unknown non-lipid enveloped viruses that may be contained in the clotting factor concentrates, because these are resistant to the existing viral inactivating techniques. The possibility of HIV itself mutating into a non-lipid enveloped virus emphasizes the need to seek and use safer products.