Epidemic of parvovirus B19 and disease severity in pregnant people, Denmark, January to March 2024.

We report an epidemic of parvovirus B19 infections in Denmark during the first quarter of 2024, with a peak incidence 3.5 times higher than during the most recent epidemic in 2017. In total, 20.1% (130/648) of laboratory-confirmed cases were pregnant. Severe adverse outcomes were observed among 12.3% (16/130) of pregnant people and included foetal anaemia, foetal hydrops and miscarriage. Parvovirus B19 infection is not systematically monitored, but a national laboratory-based surveillance system is currently being established in Denmark.

Outcome of fetuses with congenital parvovirus B19 infection: systematic review and meta-analysis.

OBJECTIVE: To explore the outcome of fetuses affected by congenital parvovirus B19 (PB19) infection, with or without signs of hydrops on ultrasound. METHODS: PubMed, EMBASE and CINAHL databases were searched for studies reporting on prenatal diagnosis and outcome of fetal PB19 infection. The outcomes explored were miscarriage, perinatal death (PND), intrauterine death, neonatal death, spontaneous resolution of hydrops or fetal anemia, need for intrauterine transfusion (IUT), resolution of hydrops or anemia after transfusion, fetal loss following transfusion, abnormal brain scan after birth and abnormal neurodevelopmental outcome. Outcomes were reported according to the presence or absence of signs of hydrops on ultrasound. A subgroup analysis was performed including hydropic and non-hydropic fetuses diagnosed at < 20 weeks and ≥ 20 weeks of gestation. Meta-analyses of proportions and meta-analyses using individual-data random-effects logistic regression were performed to analyze the data. RESULTS: Thirty-five observational studies were included, involving 611 fetuses affected by PB19 infection. The risks of miscarriage (odds ratio (OR), 11.5; 95% CI, 2.7-49.7) and PND (OR, 4.2; 95% CI, 1.6-11.0) were higher in fetuses with PB19 infection presenting, compared with those not presenting, signs of hydrops on ultrasound. In fetuses affected by hydrops, spontaneous resolution of the infection, defined as disappearance of hydrops without need for IUT, occurred in 5.2% (95% CI, 2.5-8.8%) of cases whereas, in the group of fetuses not affected by hydrops, infection resolved in 49.6% (95% CI, 20.7-78.6%) of cases. IUT was performed in 78.7% (95% CI, 66.4-88.8%) of hydropic and in 29.6% (95% CI, 6.0-61.6%) of non-hydropic fetuses affected by congenital PB19 infection and resolution of the infection after IUT occurred in 55.1% (95% CI, 34.0-75.3%) and in 100% (95% CI, 57.3-100%) of cases, respectively. The risk of fetal loss after IUT was higher in fetuses affected compared with those not affected by hydrops (OR, 9.8; 95% CI, 2.8-34.6). The prevalence of abnormal brain imaging was 9.8% (95% CI, 2.5-21.0%) in fetuses affected and 0.0% (95% CI, 0.0-7.0%) in those not affected by hydrops, whilst the corresponding figures for abnormal neurodevelopmental outcome were 9.5% (95% CI, 2.6-20.2) and 0.0% (95% CI, 0.0-7.5), respectively; however, statistical power to assess these outcomes was inadequate due to the small number of included cases. CONCLUSIONS: Hydrops is the main determinant of mortality and adverse perinatal outcome in fetuses with PB19 infection. Perinatal outcome in non-hydropic fetuses is generally favorable. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Ultrasound Findings Associated With Antepartum Viral Infection.

This article reviews the sonographic manifestations of fetal infection and the role of ultrasound in the evaluation of the fetus at risk for congenital infection. Several ultrasound findings have been associated with in utero fetal infections. For the patient with a known or suspected fetal infection, sonographic identification of characteristic abnormalities can provide useful information for counseling and perinatal management. Demonstration of such findings in the low-risk patient may serve to identify the fetus with a previously unsuspected infection. The clinician should understand the limitations of ultrasound in the prenatal diagnosis of congenital infection and discuss them with the patient.

Clinical features of 10 fetuses with prenatally diagnosed parvovirus b19 infection and fetal hydrops.

OBJECTIVES: To evaluate the clinical features of fetuses with prenatally diagnosed parvovirus B19 infection and fetal hydrops. METHODS: Parvovirus infection was diagnosed by PCR analysis of amniotic fluid or fetal blood. Fetal anemia was assessed by Doppler measurements of the middle cerebral artery peak systolic velocity (MCA-PSV) and confirmed by fetal blood. Intrauterine transfusions (IUT) were performed only if the MCA-PSV was > 1.5°MoM. RESULTS: In our study population 10 cases of parvovirus infection which were associated with fetal hydrops were reviewed. The median gestational age at diagnosis was 21 (16.3-24.2) weeks. Five of our cases received IUT and four fetuses survived. The remaining five cases were managed conservatively and two fetuses survived. CONCLUSIONS: The survival rate for parvovirus infection associated with fetal hydrops was 60%. MCA-PSV and IUT are useful for the management and treatment of fetal anemia due to parvovirus infection.

Parvovirus B19 infection in pregnancy.

OBJECTIVES: This guideline reviews the evidence relating to the effects of parvovirus B19 on the pregnant woman and fetus, and discusses the management of women who are exposed to, who are at risk of developing, or who develop parvovirus B19 infection in pregnancy. OUTCOMES: The outcomes evaluated were maternal outcomes including erythema infectiosum, arthropathy, anemia, and myocarditis, and fetal outcomes including spontaneous abortion, congenital anomalies, hydrops fetalis, stillbirth, and long-term effects. EVIDENCE: Published literature was retrieved through searches of PubMed and The Cochrane Library on July 8, 2013, using appropriate controlled vocabulary (MeSH terms "parvovirus" and "pregnancy") and key words (parvovirus, infection, pregnancy, hydrops). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date restrictions but results were limited to English or French language materials. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, and national and international medical specialty. VALUES: The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Recommendations 1. Investigation for parvovirus B19 infection is recommended apart of the standard workup for fetal hydrops or intrauterine fetal death. (II-2A) 2. Routine screening for parvovirus immunity in low-risk pregnancies is not recommended. (II-2E) 3. Pregnant women who are exposed to, or who develop symptoms of, parvovirus B19 infection should be assessed to determine whether they are susceptible to infection (non-immune) or have a current infection by determining their parvovirus B19 immunoglobulin G and immunoglobulin M status. (II-2A) 4. If parvovirus B19 immunoglobulin G is present and immunoglobulin M is negative, the woman is immune and should be reassured that she will not develop infection and that the virus will not adversely affect her pregnancy. (II-2A) 5. If both parvovirus B19 immunoglobulin G and immunoglobulin M are negative (and the incubation period has passed), the woman is not immune and has not developed the infection. She should be advised to minimize exposure at work and at home. Absence from work should be considered on a case-by-case basis. (II-2C) Further studies are recommended to address ways to lessen exposure including the risk of occupational exposure. (III-A) 6. If a recent parvovirus B19 infection has been diagnosed in the woman, referral to an obstetrician or a maternal-fetal medicine specialist should be considered. (III-B) The woman should be counselled regarding risks of fetal transmission, fetal loss, and hydrops and serial ultrasounds should be performed every 1 to 2 weeks, up to 12 weeks after infection, to detect the development of anemia (using Doppler measurement of the middle cerebral artery peak systolic velocity) and hydrops. (III-B) If hydrops or evidence of fetal anemia develops, referral should be made to a specialist capable of fetal blood sampling and intravascular transfusion. (II-2B).

Objectifs : La présente directive clinique passe en revue les données probantes en ce qui concerne les effets qu'exerce le parvovirus B19 sur la femme enceinte et le fœtus, et traite de la prise en charge (pendant la grossesse) des femmes qui sont exposées au parvovirus B19, qui sont exposées à des risques de contracter une infection au parvovirus B19 ou qui contractent une telle infection. Issues : Les issues évaluées ont été les issues maternelles (dont le mégalérythème épidémique, l'arthropathie, l'anémie et la myocardite) et fœtales (dont l'avortement spontané, les anomalies congénitales, l'anasarque fœtoplacentaire, la mortinaissance et les effets à long terme de l'infection). Résultats : La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed et The Cochrane Library le 8 juillet 2013 au moyen d'un vocabulaire contrôlé (« parvovirus ¼ et « pregnancy ¼) et de mots clés (« parvovirus ¼, « infection ¼, « pregnancy ¼, « hydrops ¼) appropriés. Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Aucune restriction n'a été imposée en matière de date; toutefois, les résultats ont été limités aux documents rédigés en anglais ou en français. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. Valeurs : La qualité des résultats est évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau). Recommandations 1. La tenue d'une exploration visant l'infection au parvovirus B19 est recommandée dans le cadre du bilan standard mis en œuvre dans les cas d'anasarque fœtoplacentaire ou de décès fœtal intra-utérin. (II-2A) 2. Le dépistage de l'immunité au parvovirus n'est pas systématiquement recommandé dans le cadre des grossesses n'étant exposées qu'à de faibles risques. (II-2E) 3. Les femmes enceintes qui sont exposées au parvovirus B19 ou qui en viennent à présenter des symptômes associés à l'infection à ce dernier devraient faire l'objet d'un examen visant à établir (par la détermination de leur statut quant à l'immunoglobuline G et à l'immunoglobuline M du parvovirus B19) si elles sont vulnérables à l'infection (non immunisées) ou si elles présentent bel et bien une infection en cours. (II-2A) 4. Lorsque les résultats sont positifs en ce qui concerne la présence de l'immunoglobuline G du parvovirus B19 et qu'ils sont négatifs en ce qui concerne celle de l'immunoglobuline M, la patiente en question est alors immunisée; son fournisseur de soins peut donc la rassurer en lui indiquant qu'elle n'en viendra pas à connaître cette infection pendant la grossesse et que le virus ne donnera pas lieu à des conséquences indésirables pendant celle-ci. (II-2A) 5. Lorsque les résultats sont négatifs tant en ce qui concerne l'immunoglobuline G que l'immunoglobuline M du parvovirus B19 (et que la période d'incubation est terminée), la patiente n'est alors pas immunisée et n'a pas contracté l'infection. Bien que l'on doive lui conseiller de minimiser le risque d'exposition au travail et à la maison, rien n'indique que le retrait du milieu de travail atténue le risque de transmission. (II-2C) La tenue d'autres études visant à explorer les façons d'atténuer le risque d'exposition (y compris le risque d'exposition professionnelle) est recommandée. (III-A) 6. Lorsqu'une infection récente au parvovirus B19 a été diagnostiquée, l'orientation de la patiente en question vers un obstétricien ou un spécialiste de la médecine fœto-maternelle devrait être envisagée. (III-B) Des services de counseling à l'égard des risques de transmission fœtale, de mort fœtale et d'anasarque devraient lui être offerts. Des échographies en série devraient être menées toutes les 1 à 2 semaines, jusqu'à 12 semaines à la suite de l'infection, pour détecter l'apparition d'une anémie (en ayant recours à la mesure du pic de vitesse systolique de l'artère cérébrale moyenne par étude Doppler) et d'une anasarque. (III-B) Lorsqu'une anasarque ou des signes d'anémie fœtale en viennent à se manifester, la patiente devrait être orientée vers un spécialiste étant en mesure de procéder à un prélèvement de sang fœtal et une transfusion intravasculaire devrait être mise en œuvre. (II-2B).

Parvovirus B19 in Pregnancy.

Importance: Although the risk of parvovirus B19 infection during pregnancy and subsequent risk of adverse fetal outcome are low, understanding management practices is essential for proper treatment of fetuses with nonimmune hydrops fetalis. In addition, continued investigation into delivery management, breastfeeding recommendations, and congenital abnormalities associated with pregnancies complicated by parvovirus B19 infection is needed. Objective: This review describes the risks associated with parvovirus B19 infection during pregnancy and the management strategies for fetuses with vertically transmitted infections. Evidence Acquisition: Original articles were obtained from literature search in PubMed, Medline, and OVID; pertinent articles were reviewed. Results: Parvovirus B19 is a viral infection associated with negative pregnancy outcomes. Up to 50% of people of reproductive age are susceptible to the virus. The incidence of B19 in pregnancy is between 0.61% and 1.24%, and, overall, there is 30% risk of vertical transmission when infection is acquired during pregnancy. Although most pregnancies progress without negative outcomes, viral infection of the fetus may result in severe anemia, congestive heart failure, and hydrops fetalis. In addition, vertical transmission carries a 5% to 10% chance of fetal loss. In pregnancies affected by fetal B19 infection, Doppler examination of the middle cerebral artery peak systolic velocity should be initiated to surveil for fetal anemia. In the case of severe fetal anemia, standard fetal therapy involves an intrauterine transfusion of red blood cells with the goal of raising hematocrit levels to approximately 40% to 50% of total blood volume. One transfusion is usually sufficient, although continued surveillance may indicate the need for subsequent transfusions. There are fewer epidemiologic data concerning neonatal risks of congenital parvovirus, although case reports have shown that fetuses with severe anemia in utero may have persistent anemia, thrombocytopenia, and edema in the neonatal period. Conclusions and Relevance: Parvovirus B19 is a common virus; seropositivity in the geriatric population reportedly reaches 85%. Within the pregnant population, up to 50% of patients have not previously been exposed to the virus and consequently lack protective immunity. Concern for parvovirus B19 infection in pregnancy largely surrounds the consequences of vertical transmission of the virus to the fetus. Should vertical transmission occur, the overall risk of fetal loss is between 5% and 10%. Thus, understanding the incidence, risks, and management strategies of pregnancies complicated by parvovirus B19 is essential to optimizing care and outcomes. Further, there is currently a gap in evidence regarding delivery management, breastfeeding recommendations, and the risks of congenital abnormalities in pregnancies complicated by parvovirus B19. Additional investigations into optimal delivery management, feeding plans, and recommended neonatal surveillance are needed in this cohort of patients.

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

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

Analysis about the influence on the fetus infected with parvovirus B19 using amniotic erythropoietin and troponin-T.

OBJECTIVE: We tried to identify the influence on the fetus infected with parvovirus B19 (PB19) and retrospectively analyze the severity of fetal infection. METHODS: Twenty pregnant women who developed maternal PB19 infection were included in this study. A total of 20 amniotic fluid samples were collected for measurement of PB19-DNA, erythropoietin (Epo) and troponin-T (TnT). RESULTS: Of the 5 fetuses with hydrops, 2 were rescued by fetal therapy. Significant differences between groups were found for Epo and TnT: Epo 107.1 ± 45.3 mU/ml and TnT 0.040 ± 0.028 ng/ml (mean ± standard deviation) for the symptomatic fetus group; and Epo 18.9 ± 13.7 mU/ml and TnT 0.008 ± 0.014 ng/ml for the asymptomatic fetus group (p = 0.043 for both variables). Setting Epo ≥50 mU/ml as the predictor of disease onset resulted in an Odds ratio of 56.0, with a 95 % confidence interval of 7.68-1,108.76. CONCLUSION: The study has determined an amniotic Epo level of ≥50 mU/ml as a factor of the influence on the fetus infected with PB19. The measurement of amniotic Epo level combined with amniotic TnT level is effective for determining the severity of fetal hypoxia.

Ballantyne syndrome and congenital anaemia associated with Parvovirus B19 infection: case report and review.

Acute maternal Parvovirus B19 infection affects about 1% of all pregnancies worldwide. Diaplacental transmission of Parvovirus B19 during the second trimester can cause complications like foetal hydrops, premature delivery or foetal loss in about 20-30% of these pregnancies, whereas the majority of maternal infections remain clinically silent. In individual cases, foetoplacental hydrops (of various origins) can trigger a rare form of Preeclampsia in the pregnant woman. The developing maternal oedema in this situation apparently "mirrors" the hydropic state of the foetus. The symptom triad of foetal hydrops, foetoplacental oedema and maternal anasarca defines Ballantyne syndrome. We report a case of Parvovirus-induced Ballantyne syndrome including a 10-year follow-up of mother and child. While the mother recovered rapidly after (preterm) delivery, the infection complicated the first months of life of the neonate. Congenital transfusion-dependent red cell aplasia and cholestatic hepathopathy took a chronic course but resolved under IVIG treatment. Follow-up now finds both the former neonate and the mother entirely recovered. Current knowledge on Ballantyne syndrome as well as perigestational Parvovirus infections including congenital anaemia is briefly reported and pathophysiological hypotheses are discussed.

Polymicrogyria in a fetus with human parvovirus B19 infection: a case with radiologic-pathologic correlation.

We report the prenatal magnetic resonance imaging (MRI) appearance of polymicrogyria with pathologic correlation in a fetus with congenital parvovirus B19 infection. Prenatal ultrasound revealed non-immune hydrops, but detected no fetal brain abnormalities. A subsequent fetal MRI scan performed at 23 weeks' gestation demonstrated bilateral polymicrogyria, which was confirmed at autopsy. To our knowledge, prenatal diagnosis of polymicrogyria in association with congenital parvovirus B19 infection has not been previously described. This case provides further evidence for brain abnormalities resulting from congenital parvovirus B19 infection, and suggests that fetal neuroimaging with MRI would be of value in suspected cases of congenital parvovirus infection.

Chronic histiocytic intervillositis with cytomegalovirus placentitis in a case of hydrops fetalis.

Chronic histiocytic intervillositis (CHI) is an infrequent inflammatory placental disorder associated with unfavorable pregnancy outcomes and a high rate of recurrence. This disorder is thought to reflect a maternal delayed hypersensitivity response to fetal antigen(s) in placental tissue. We report a case of a 20-week-gestation hydropic fetus in which the placenta showed chronic histiocytic intervillositis with cytomegalovirus placentitis. Immunophenotyping studies supported a delayed hypersensitivity response. This is the first report of these two diseases co-occurring, raising the possibility of a relationship between chronic histiocytic intervillositis and infection. Chronic histiocytic intervillositis may represent an idiosyncratic immune response, in this case to cytomegalovirus.

Viral detection in hydrops fetalis, spontaneous abortion, and unexplained fetal death in utero.

This study was undertaken to investigate the occurrence of viral infection in fetal death by examining tissues for the presence of DNA of several viral agents. Tissue specimens including heart, kidney, liver, lung, and placenta of 73 cases of fetal death were examined with 27 cases of elective termination of pregnancy as a control group. DNA extracted from these samples was tested for the presence of HSV, CMV, EBV, VZV, HHV-6, HHV-7, and PVB19. Viral DNA was found in one or more tissue samples from 25/73 cases (34%): CMV in 20, HSV in 5, parvovirus B19 in 5, HHV-7 in 3, and HHV-6 in 2. The presence of HHV-6 in fetal tissue has been reported rarely. No study so far has reported the detection of HHV-7 in fetal tissues with normal or adverse outcomes. Viral DNA was not found in any of the termination of pregnancy samples. Among the positive cases, eight had dual infection. One further case was positive for three viruses: HSV, CMV, and HHV-7. HHV-6 was the sole infectious agent in two cases, HHV-7 in one case, PVB19 in three, and CMV in ten cases. The finding of multiple viral DNA in 12% of the cases suggests the involvement of complex risk factors in cases of fetal loss. Although the cause of fetal death often includes other factors (e.g., chromosomal abnormalities) these data suggest the incidence of viral infective etiology may be higher than considered previously. However, larger studies are required to establish this link.

Parvovirus B19 infection in pregnancy: new insights and management.

In this article, we review the virology, pathology, epidemiology and clinical spectrum of intrauterine human parvovirus B19 (B19V) infection, including intrauterine fetal death, non-immune hydrops fetalis, thrombocytopenia and neurological manifestations such as pediatric stroke and perivascular calcifications. In addition, we discuss the new insights into the neurodevelopmental outcome of intrauterine B19V infection. Current diagnosis and management of B19V infection is summarized, including a diagnostic and follow-up flowchart for practical clinical use.

Ultrasound diagnosis, management and prognosis in a consecutive series of 27 cases of fetal hydrops following maternal parvovirus B19 infection.

INTRODUCTION: Fetal hydrops caused by anemia from parvovirus B19 infection (FH-B19) is rare. Doppler measurement of the middle cerebral artery peak systolic velocity (PSV-MCA) improves its prenatal diagnosis, but its frequency and prognosis are still poorly known. Despite improved survival due to in utero transfusions, the possibility of late neurological sequelae makes prognosis uncertain. OBJECTIVES: To assess the frequency, management and prognosis of a consecutive series of FH-B19 observed over a 15-year period. METHODS: Retrospective study of 27 cases of FH-B19, that is, 3/100,000 births, 24 of them discovered during routine second-trimester ultrasound. All but 1 case (96.2%) had at least four of the six ultrasound signs that Saltzman et al. [Obstet Gynecol 1989;74:106-111] suggested as indicators of anemia. Of the fetuses tested, 80% had a PSV-MCA >1.5 MoM, also indicative of anemia. Of the 19 fetuses treated by exchange transfusions, 11 were liveborn compared with 2 of the 6 not so treated (57.8 vs. 33.3%, NS). The survival rate was higher during the second half of the study period (23.1 vs. 71.4%, p < 0.02) for less severe anemia (p < 0.03) and for repeated transfusions (p = 0.03). In our series, 1 case of prenatal cerebral atrophy was identified on screening. All 13 liveborn children appeared healthy at the age of 1 year. CONCLUSION: In cases of fetal hydrops, Saltzman et al.'s ultrasound criteria and PSV-MCA measurement made it possible to determine the likelihood that anemia is the cause of the hydrops and to measure its intensity. Use of these techniques allowed us to choose the most appropriate treatment (transfusion or not, depending on the degree of anemia), and survival improved notably in our series.

Postnatal IVIG treatment for persistent anaemia in neonate due to congenital parvovirus infection.

Congenital parvovirus B19 infection is a rare but serious condition that can result in hydrops fetalis and fetal death. Due to the virus' cytotoxic effect on fetal red blood cell precursors, postnatal infection can cause a neonatal viremia and secondary pure red cell aplasia. Here, we describe a case of congenital parvovirus infection in a preterm infant complicated by hydrops fetalis and chronic anaemia that responded to postnatal treatment with intravenous immunoglobulin administered on day of life 44. After treatment, the anaemia resolved as the neonate exhibited interval increases in haemoglobin, haematocrit and reticulocyte count with no subsequent need for red blood cell transfusions.

Diagnosis of fetal parvovirus B19 infection: value of virological assays in fetal specimens.

OBJECTIVE: The purpose of our work was to examine the most reliable laboratory diagnosis of fetal parvovirus B19 infection in hydropic fetuses by evaluating the most appropriate clinical sample and laboratory test. DESIGN: B19 DNA detection in fetal samples and serological signs of B19 infection in the respective mothers. Samples collected between January 2000 and July 2008. SETTING: Microbiology, University of Bologna, Bologna, Italy. SAMPLES: One hundred thirty-five fetal samples (58 fetal cord blood and 77 amniotic fluid samples) and 109 serum samples collected from 109 pregnant women. METHODS: Validated and certified in situ hybridisation assay (ISH) and polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA) were performed on fetal samples to detect B19 DNA. B19-specific antibodies were investigated in maternal serum samples by a commercial enzyme immunoassay. MAIN OUTCOME MEASURES: Parvovirus B19 DNA detection in fetal specimens was analysed in relation to maternal serological signs of infection. RESULTS: Parvovirus B19 DNA was detected in 22.41% of fetal cord blood and 36.36% of amniotic fluid samples. A statistically significant difference was found between DNA detection by ISH (23.70%) and PCR-ELISA (14.81%) (P= 0.004). Only 11.76% of fetuses with virological diagnosis of B19 infection were from women with serological signs of acute/recent B19 infection. CONCLUSIONS: Diagnosis of fetal parvovirus B19 infection cannot always rely on maternal serological investigations but rather on the virological analysis of fetal samples. Both fetal cord blood and amniotic fluid samples are suitable for diagnosis, but the detection of B19 DNA in the cells of amniotic fluid samples by ISH proved to be the most reliable diagnostic system.

Discordant outcomes in a case of parvovirus b19 transmission into both dichorionic twins.

Maternal infection with parvovirus B19 during pregnancy can cause aplastic anemia in the fetus and may lead to nonimmune fetal hydrops and fetal demise. Twin pregnancies complicated by infection due to parvovirus B19 are very rare clinical events. We present a dichorionic, diamniotic, dizygotic twin pregnancy after in vitro fertilization with parvovirus B19 infection and viral transmission to both twins, but different outcomes. At 19 weeks gestation, hydrops fetalis was diagnosed for male twin A, female twin B did not show any abnormalities. At 22 weeks gestation an acute parvovirus B19 infection was detected and twin A was diagnosed with intrauterine fetal death (IUFD) by ultrasound at 23 weeks gestation. Viral DNA was detected in maternal blood as well as in placenta and liver tissue of this twin. Twin B was born at 35 weeks gestation asymptomatically and no signs of hydrops or other congenital anomalies but viral DNA was detected by PCR in serum. At the age of 2 years, both IgG titres against B19 and parvovirus DNA amplification copies were still positive in plasma of the surviving twin, but no clinical signs were detectable. It is remarkable that both twins were infected with parvovirus B19 early in pregnancy but showed a discordant clinical outcome. Our case report describes the rare occurrence of an intrauterine fetal death (IUFD) of one twin and the asymptomatic infection of the other in a twin pregnancy.

Detection of the human Parvovirus B19 in nonimmune hydrops fetalis using immunohistochemistry and nested-PCR in formalin-fixed and paraffin-embedded placenta and fetal tissues.

The aim of the present study was to determine whether there is an association between Parvovirus B19 infection and hydrops fetalis setting in fetus and neonate. Twenty-nine samples were analyzed by three methods. Each sample was histologically examined for viral nuclear inclusions in fetal organs and placenta, then immunohistochemical study using Parvovirus B19 antibody that recognized the VP2 protein of the Parvovirus B19 capsid was done in tissue embedded in paraffin (lungs, liver, thymus, kidneys, heart and placenta). Nested-PCR analysis was done after DNA extraction from paraffin blocks and using specific primers of the Parvovirus B19 VP1 gene. Apparent causes of hydrops were eliminated such as metabolic diseases, cardiac failure or malformation. The standard histological study objects viral inclusion in one case (lung tissue). However, the immunohistochemical study was negative in all cases. Nested-PCR demonstrates the presence of the viral DNA in five cases. Our study demonstrates that the implication of Parvovirus B19 in hydrops fetalis must be affirmed by the use of more than one method. Nested-PCR is the most sensitive method in our study and can be easily used for the detection of Parvovirus B19 in formalin-fixed paraffin-embedded tissues.