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Resume Le Parvovirus B19 (B19V) a longtemps represente le seul erythrovirus humain connu, avec une diversite genetique faible. Cette notion s’est trouvee remise en question par la mise en evidence d’un variant (souche V9) genetiquement distinct des B19V. L’analyse des sequences d’autres souches apparentees au V9 a ensuite montre une organisation des erythrovirus humains en trois genotypes distincts. La transmission de ces virus se fait principalement par voie respiratoire, mais la voie transfusionnelle est possible. Chez les receveurs immunocompetents et immunises, la contamination est sans impact clinique. En revanche, chez les patients atteints d’anemie hemolytique chronique et non immunises, chez les femmes enceintes seronegatives et chez les patients immunodeprimes, l’infection transfusionnelle peut avoir des consequences importantes. Le depistage du B19V dans les dons de sang n’est pas realise, mais il est regulierement debattu, notamment de maniere ciblee pour ces trois categories de receveurs a risque. En revanche, la recherche de l’ADN viral est effectuee dans les pools de plasmas destines a la preparation des medicaments derives du sang, avec un seuil de detection requis de 10 4 UI/ml. A la lumiere de donnees recentes revelant une diversite genetique sous-estimee jusqu’ici des erythrovirus humains, les tests de detection du genome viral font l’objet d’une attention particuliere quant a leur validation vis-a-vis de cette variabilite genetique, afin de garantir une securite optimale. Par ailleurs, la decouverte de nouveaux parvovirus transmissibles par le sang, tels que le PARV4, pose la question de la securite transfusionnelle vis-a-vis de cet agent, car les consequences cliniques de ce parvovirus humain ne sont pas encore connues.

Resume Le parvovirus B19 (PV B19) est responsable de nombreux tableaux cliniques dont les plus frequents sont le megalerytheme, la crise erythroblastopenique des anemies hemolytiques et l'hydrops fœtalis. Une polyarthrite et des polyarthralgies accompagnent, chez l'adulte jeune, l'eruption cutanee dans 60 % des cas. Les signes predominent aux extremites et s'amendent habituellement en une semaine (extremes 2 a 21 j). Le diagnostic est affirme sur la serologie IgM anti-PV B19, affirmant le caractere recent de l'infection. Des tableaux de polyarthrite plus prolongee sont parfois observes, sans doute lies a la presence d'alleles d'histocompatibilite DR4. Certaines de ces formes s'accompagnent de la presence transitoire de facteurs rhumatoides. D'autres auto-anticorps sont produits a la suite d'une infection a PV B19 tels des anti-noyaux, des anti-ADN, des anti-SSA/SSB, des anti-phospholipides. Outre le fait que l'infection aigue a PV B19 puisse simuler une PR debutante ou un lupus systemique (eruption des joues en forme de lupus, cytopenie,...), de rares observations de PR erosives ou de lupus succedant a une infection a PV B19 ont ete rapportees avec isolement d'ADN de PV B19 dans les tissus synoviaux ou les cellules sanguines par des methodes de PCR. Les etudes portant sur de grandes series laissent penser que cette etiologie parvovirale est tres accessoire. Des vascularites touchant les petits vaisseaux (purpura rhumatoide, maladie de Wegener), les vaisseaux de moyen calibre (PAN) et de gros calibre (maladie de Horton) peuvent succeder a une infection a PV B19. Il s'agit egalement de cas cliniques peu nombreux.

Background: Erythema infectiosum (fifth disease) is a common benign pediatric condition caused by B19 parvovirus. It can be identified clinically by a “slapped cheek” appearance that is often followed by reticulated exanthem on the trunk and extremities. Objective: This review article provides a concise overview of erythema infectiosum. Methods: The article is divided into the followings sections: background, epidemiologic characteristics, clinical description, diagnosis, differential diagnosis, laboratory diagnosis, prognosis, and management. Results: Erythema infectiosum is found to cause a fairly prominent classic rash and generalized symptoms. Conclusion: Although erythema infectiosum has many distinctive symptoms, the prognosis is excellent because the condition in children is usually self-limited.

This chapter discusses parvoviruses, small viruses with unenveloped icosahedral capsids that contain a single-stranded DNA genome. The B19 parvovirus is the only member of the Parvoviridae family that is known to cause diseases in humans. It is the pathogen responsible for the childhood “fifth disease,” and presents differently in adults and children. The chapter reviews the taxonomy of the parvovirus family, in which B19 and closely related simian parvoviruses constitute the Erythrovirus genus, and it discusses the B19 parvovirus’s peculiar and extreme tropism for human erythroid progenitor cells that are responsible for the generation of circulating erythrocytes. The chapter details the testing, evaluation, and treatment of patients presenting with parvovirus disease.

Inhibitors against factor XI (FXI) have been frequently described in patients who acquired inhibitors (due to auto-immune disorders, malignancies or infections), but less often in those with a congenital deficiency of this factor, who had received plasma infusions. The present report concerns one such inhibitor found in the plasma of a patient with chronic myelomonocytic leukaemia and infected by B19 parvovirus, who was neither a heterozygote nor a homozygote for FXI deficiency, and who had no bleeding tendency despite a very low FXI level. Taking this case into account, we discuss and present the clinical and biological features of acquired FXI deficiency caused by an inhibitor.

The broad spectrum of clinical manifestations associated with B19 parvovirus often allows the infection to go unrecognized. We tested for the presence of B19 parvovirus and the specific serological response in serum from hospitalized patients submitted for viral investigations without any specific indications for B19 parvovirus. We diagnosed human parvovirus B19 infection in four paediatric patients showing different clinical manifestations. The patients, aged between 5 and 8 years, were admitted to hospital for: (1) petechial rash; (2) mononucleosis-like syndrome; (3) neurological syndrome; and (4) respiratory disease (in an immunodeficient patient).

We report a successful treatment of a B19 parvovirus-induced fetal hydrops diagnosed at 16 weeks of gestation. This disease could be corrected by means of a unique intraperitoneal blood transfusion performed at 18 weeks, once diagnosis was established. The delivery occurred at 36 weeks, leading to the birth of a healthy baby. This case suggests that transfusion should be attempted, as the spontaneous fetal recovery remains uncertain and shows that intraperitoneal blood transfusion is an effective therapeutic option of the B19 parvovirus-induced anemia, in the absence of a viral myocarditis.

An automated method to identify B19 amplicons, directly labelled with digoxigenin during amplification reaction was developed. The labelled amplicons were hybridized with a biotinylated B19 oligo-probe and captured on commercially available test tubes coated with streptavidin. The hybridized amplicons labelled with digoxigenin were detected using anti-digoxigenin Fab fragments conjugated to peroxidase and the colourimetric reaction automatically evaluated as an immunoenzymatic assay. Fifty serum samples were tested by the assay and the results were in accordance with those obtained by Southern blot analysis of amplified products. Due to the high sensitivity, specificity and reproducibility shown, the assay seems to be a practical and reliable test for the diagnosis of B19 infection and can be easily adapted to identify any digoxigenin-labelled amplified product of viral genomes.

A spontaneous remission occurred after 3 years of regular transfusions in a cortico resistant Diamond Blackfan anaemia. However after 1 year of transfusion independence an apparent relapse was observed which was transient and could be attributed to a B19 parvovirus primary infection. Previous inapparent impairment of erythropoiesis can be transiently spotlighted by B19 parvovirus primary infection.

Introduction B19 Parvovirus causes a common childhood rash – ‘Slapped Cheek Syndrome’, however Parvovirus can also infect adults. Infection during pregnancy can cause serious complications for the fetus. In Sunderland there was a Parvovirus epidemic in 2008. Aim To examine the management of pregnant women in the Sunderland area exposed to Parvovirus from 2007 to 2008. Methods A complex filtration process was used for patient selection. It comprised as follows: The Parvovirus antibody screening log Sunderland Royal Hospital electronic system (HISS) Documentation in the maternity notes 23 standards were created. Results Sample size 103. 62% of women were immune to Parvovirus. 28% were susceptible. 10% were infected but had normal pregnancy outcome. 98% had no documentation of reassurance in their notes. 89% had no documentation of the date of exposure. 59% of those susceptible did not have 4-week follow-up sampling. Conclusion The current system of care of pregnant women who are susceptible to Parvovirus is ineffective. There is poor communication about their immune status and documentation of significant information, such as date of exposure, is incomplete. Recommendation (1) Health professionals should give priority to the care of pregnant women reporting exposure to Parvovirus. (2) The Antenatal Screening Midwife should coordinate the management of Parvovirus results. (3) A proforma-based care pathway should be established for pregnant women exposed to Parvovirus to improve documentation and management.

B19 parvovirus infection is a principal cause of transient bone marrow suppression in patients with chronic haemolytic anaemias. Acute infection is described in a family of five individuals with hereditary spherocytosis; three of them developed marked hypoplastic anaemia.

Pure red cell aplasia caused by B19 parvovirus infection after autologous blood stem cell transplantation in a patient with chronic lymphocytic leukemia

Persistant B19 Parvovirus infection is a treatable cause of anemia in AIDS. Her diagnosis (Immunoassays for antivirus antibodies or DNA Hybridization studies) and her therapy (Immunoglobulins) is able to prevent corticosteroids and to stop AZT.

The case of premature infant with nonimmune hydrops secondary to human parvovirus B19 infection is presented. The infection was not suspected clinically. The fetal autopsy showed intranuclear inclusions in erythroid cells that stained positively with a DNA hybridization probe for B19 parvovirus.

A rapid dot blot hybridization assay for the detection of B19 parvovirus DNA in human sera was developed. Small portions of four serum samples were mixed, filtered onto a nylon membrane, and hybridized with a digoxigenin-labeled DNA probe; for each membrane, 380 serum samples could be tested. When a dot was positive by the hybridization assay, the four serum samples dotted together were separately tested to identify the sample positive for B19 DNA. A total of 10,150 serum samples submitted for viral serological and laboratory investigation with no specific requests for B19 testing were analyzed. Nine serum samples were positive for B19 DNA by dot blot hybridization assay, and the results were confirmed by electron microscopy. This method has proven to be reliable, economical in terms of time and costs, and useful for large-scale screening of clinical specimens, both for diagnostic work and for a source of antigen.