New atypical epidemiological profile of parvovirus B19 revealed by molecular screening of blood donations, France, winter 2023/24.

In France, blood donations are tested in pools of 96 samples for parvovirus B19 (B19V) DNA to discard plasma for fractionation when it contains high viral loads. Between January 2015 and March 2024, B19V-positive donations decreased during the COVID-19 pandemic, followed by a strong rebound in 2023 and unusually high circulation during winter 2023/24 (ca 10 times higher December 2023-March 2024 vs the pre-pandemic period). Variations over time are probably related to measures implemented to limit SARS-CoV-2 spread.

A Multiplex Fluorescence of Loop Primer Upon Self-Dequenching Loop-Mediated Isothermal Amplification Assay for the Detection of Epstein-Barr Virus and Human Parvovirus B19 in Clinical Transplant Samples.

Viral infections are major causes of mortality in solid-organ and hematopoietic stem cell transplant recipients. Epstein-Barr virus (EBV) and Parvovirus B19 (B19V) are among the common viral infections after transplantation and were recommended for increased screening in relevant guidelines. Therefore, the development of rapid, specific, and cost-effective diagnostic methods for EBV and B19V is of paramount importance. We applied Fluorescence of Loop Primer Upon Self-Dequenching Loop-mediated Isothermal Amplification (FLOS-LAMP) for the first time to develop a novel multiplex assay for the detection of EBV and B19V; the fluorophore attached to the probe are self-quenched in unbound state. After binding to the dumbbell-shaped DNA target, the fluorophore is dequenched, resulting in fluorescence development. The novel multiplex FLOS-LAMP assay was optimized by testing various ratios of primer sets. This novel assay, with great specificity, did not cross-react with the common virus. For the detection of EBV and B19V, the limits of detection could reach 969 and 798 copies/µL, respectively, and the assay could be completed within 25 min. Applying this novel assay to detect 200 clinical transplant individuals indicated that the novel assay had high specificity and good sensitivity. We developed multiplex FLOS-LAMP assay for the detection of EBV and B19V, which has the potential to become an important tool for clinical transplant patient screening.

Parvovirus in Kidney Transplant Recipients: A Single-Center Experience.

OBJECTIVES: Parvovirus testing is not done in routine clinical practice; thus, it is possible that reported parvovirus cases are just the tip of the iceberg of total prevalence. We present a single-center retrospective analysis of 22 events of parvovirus B19 anemia in 20 renal transplant recipients, among which 2 patients had recurrence. MATERIALS AND METHODS: For this descriptive analytical study, parvovirus B19 disease was defined as parvovirus infection (detection by real-time polymerase chain reaction) in the presence of anemia with clinical symptoms or bone marrow biopsy findings consistent with the diagnosis. Study duration was 18 months, from June 2021 through December 2022, and patients were enrolled from a single center. RESULTS: All patients detected with the virus had received induction with thymocyte globulin and were on standard triple drug immunosuppression. Mean age was 32 ± 12 years with median time to diagnosis of 2 months after transplant. Anemia was observed in all patients with mean hemoglobin level at presentation of 6.02 ± 1.28 g/dL. Creatinine at presentation was 1.49 mg/dL (interquartile range, 0.92-2.69 mg/dL). The most common presentation was asymptomatic patient with evaluation for anemia. During therapy, the highest median creatinine level was 2.0 mg/dL (interquartile range, 1.38-3.2 mg/dL), which was significantly higher than that at presentation (P < .018). After therapy, median creatinine level was 1.3 mg/dL, which was not significantly higher than the baseline level, demonstrating a mostly transient graft dysfunction. CONCLUSIONS: Parvovirus B19 is a relatively underreported disease in renal transplant recipients, with patients presenting with anemia and the disease causing transient graft dysfunction. Parvovirus B19 infection responds well to a decrease in immunosuppression and intravenous immunoglobulin therapy.

Detection of Parvovirus B19 genome in human heart tissue samples.

OBJECTIVE: Identifying viral genomes in human heart tissues is critical for disease diagnosis and assessment of cardiovascular damage. Human heart tissue samples obtained during a biopsy procedure are routinely used to test for the presence of viruses, as guided by clinical manifestations and prognosis. Furthermore, heart tissue samples obtained post-mortem or during a cardiac transplant procedure serve as a valuable research tool, as they allow for an in-depth assessment of cardiac pathology that can aid in our understanding of molecular pathways associated with disease. Because viral nucleic acid constitutes only a small portion of each sample's genetic material, appropriate methods are necessary for positive viral genome identification. RESULTS: Snap-frozen heart tissue samples obtained either post-mortem or during a cardiac transplant procedure were used to develop conditions for detection of Parvovirus B19. Briefly, total DNA was isolated from the heart tissue under varying conditions. A PCR-based assay with Parvovirus B19 specific primers was implemented to detect the presence of the viral genome, followed by Sanger Sequencing. The mechanical disruption of the heart tissue, as well as the cardiac tissue processing methods, had a significant effect on the DNA quality and the ability to detect the Parvovirus B19 genome.

[Hemophagocytic Syndrome Secondary to Human Parvovirus B19 Infection in an Acquired Immunodeficiency Syndrome Patient:Report of One Case].

The acquired immunodeficiency syndrome patients with compromised immunity are prone to hemophagocytic syndrome secondary to opportunistic infections.This paper reports a rare case of hemophagocytic syndrome secondary to human parvovirus B19 infection in an acquired immunodeficiency syndrome patient,and analyzes the clinical characteristics,aiming to improve the diagnosis and treatment of the disease and prevent missed diagnosis and misdiagnosis.

Clinical assessment of a point-of-care assay to determine protective vaccinal antibody titers to canine viral diseases.

Guidelines recommend that dogs are vaccinated for canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus (CAV) every 3 years. Alternatively, their antibody titers are measured and vaccines given when titers fall below a protective threshold. In this study, a point-of-care (POC) assay was compared to hemagglutination inhibition (for CPV) and virus neutralization (for CAV and CDV) assays to predict the need for revaccination Ninety-two dogs presented for vaccination were enrolled. The POC assay indicated protective titers against CDV in 79/80, CPV in 89/90, and CAV in 91/91 dogs with reference standard antibody measurements that were over a protective threshold. The sensitivity of the POC assay for to detect protective concentrations of CDV antibodies was 99% (95% confidence interval [CI 95%], 93.3-99.9%). Ten dogs were falsely considered protected against CDV by the POC assay with a specificity of 17% (CI 95%, 3.0-44.8%). The sensitivity of the POC assay for protective concentrations of CPV titers was 99% (CI 95%, 93.9-99.9%). The sensitivity of the POC assay to detect protective concentrations of CAV antibodies was 100% (CI 95%, 95.9-100%). Only classifying high-positive CDV and CPV titers on the POC assay as protective improved assay specificity to 100%, but sensitivity decreased to 51% and 76% respectively. This POC assay had a high sensitivity for the detection of protective antibody titers; however, some dogs were falsely categorized as protected, especially for CDV.

Pre-Existing Intrarenal Parvovirus B19 Infection May Relate to Antibody-Mediated Rejection in Pediatric Kidney Transplant Patients.

Viral infections can lead to transplant dysfunction, and their possible role in rejection is described. In total, 218 protocol biopsies performed in 106 children at 6, 12 and 24 months after transplantation were analyzed according to Banff '15. RT-PCR for cytomegalovirus, Epstein-Barr virus, BK virus and Parvovirus B19 was performed on blood and bioptic samples at the time of transplant and each protocol biopsy. The prevalence of intrarenal viral infection increases between 6 and 12 months after transplantation (24% vs. 44%, p = 0.007). Intrarenal Parvovirus B19 infection is also associated with antibody-mediated rejection (ABMR) (50% ABMR vs. 19% T-cell-mediated rejection, p = 0.04). Moreover, Parvovirus infection is higher at 12 months of follow-up and it decreases at 48 months (40.4% vs. 14%, p = 0.02), while in 24% of grafts, Parvovirus is already detectable at the moment of transplantation. Intrarenal Parvovirus B19 infection seems to be related to ABMR in pediatric kidney recipients. The graft itself may be the way of transmission for Parvovirus, so performance of a PCR test for Parvovirus B19 should be considered to identify high-risk patients. Intrarenal Parvovirus infection presents mainly during the first-year post-transplantation; thus, we recommend an active surveillance of donor-specific antibodies (DSA) in patients with intrarenal Parvovirus B19 infection during this period. Indeed, it should be considered a treatment with intravenous immunoglobulins in patients with intrarenal Parvovirus B19 infection and DSA positivity, even in the absence of ABMR criteria for kidney biopsy.

Molecular Profiling of Inflammatory Mediators in Human Respiratory Syncytial Virus and Human Bocavirus Infection.

Infections due to human respiratory syncytial virus (HRSV) and human bocavirus (HBoV) can mediate the release of several pro-inflammatory cytokines such as IL-6, IL-8, and TNF-α, which are usually associated with disease severity in children. In this study, the change in the expression profile of cytokines and chemokines were determined during HRSV, HBoV, and HRSV coinfection with HBoV in 75 nasopharyngeal aspirates (NPAs) samples, positive real-time reverse transcriptase PCR Assay (rRT-PCR) for HRSV (n = 36), HBoV (n = 23) infection alone or HRSV coinfection with HBoV (n = 16). The samples were collected from hospitalized children. qPCR-based detection revealed that the levels of IL-6, IL-8, IL-10, IL-13, IL-33, and G-CSF were significantly (p < 0.05) greater in patients than in controls. IL-4, IL-17, GM-CSF, and CCL-5 were significantly elevated in children with HRSV coinfection with HBoV than in other groups (p < 0.05). TNF-α, IL-6, IL-8, IL-10, IL-13, and IL-33 in children with HRSV were significantly increased in severe infections compared to mild infections. Whereas, IL-10, IL-13, and IL-33 were significantly increased in severe infection in compared a mild infection in children with HBoV. Further large-scale investigations involving isolates are needed to enhance our knowledge of the association between viral infections and cytokine expression patterns during the different stages of HRSV and HBoV infection.

Clinical Presentation of Parvovirus B19 Infection in Adults Living with HIV/AIDS: A Case Series.

Parvovirus B19 (B19V) infection varies clinically depending on the host's immune status. Due to red blood cell precursors tropism, B19V can cause chronic anemia and transient aplastic crisis in patients with immunosuppression or chronic hemolysis. We report three rare cases of Brazilian adults living with human immunodeficiency virus (HIV) with B19V infection. All cases presented severe anemia and required red blood cell transfusions. The first patient had low CD4+ counts and was treated with intravenous immunoglobulin (IVIG). As he remained poorly adherent to antiretroviral therapy (ART), B19V detection persisted. The second patient had sudden pancytopenia despite being on ART with an undetectable HIV viral load. He had historically low CD4+ counts, fully responded to IVIG, and had undiagnosed hereditary spherocytosis. The third individual was recently diagnosed with HIV and tuberculosis (TB). One month after ART initiation, he was hospitalized with anemia aggravation and cholestatic hepatitis. An analysis of his serum revealed B19V DNA and anti-B19V IgG, corroborating bone marrow findings and a persistent B19V infection. The symptoms resolved and B19V became undetectable. In all cases, real time PCR was essential for diagnosing B19V. Our findings showed that adherence to ART was crucial to B19V clearance in HIV-patients and highlighted the importance of the early recognition of B19V disease in unexplained cytopenias.

Case Report: Parvovirus B19 infection complicated by hemophagocytic lymphohistiocytosis in a heart-lung transplant patient.

Immunosuppressed patients can contract parvovirus B19, and some may experience hemophagocytic lymphohistiocytosis (HLH). Herein, we describe the first report of hemophagocytic lymphohistiocytosis in a heart-lung transplant patient with concomitant parvovirus B19 infection. The patient was treated with intravenous immune globulin (IVIG) and the features of HLH were remission. This instance emphasizes the significance of parvovirus B19 monitoring in transplant patients with anemia; if HLH complicates the situation, IVIG may be an adequate remedy. Finally, a summary of the development in diagnosing and managing parvovirus B19 infection complicated by HLH is provided.

A multiplex fluorescence-based loop-mediated isothermal amplification assay for identifying chicken parvovirus, chicken infectious anaemia virus, and fowl aviadenovirus serotype 4.

Chicken parvovirus (ChPV), chicken infectious anaemia virus (CIAV) and fowl adenovirus serotype 4 (FAdV-4) are avian viruses that have emerged in recent years and have endangered the global poultry industry, causing great economic loss. In this study, a multiplex fluorescence-based loop-mediated isothermal amplification (mLAMP) assay for detecting ChPV, CIAV and FAdV-4 was developed to simultaneously diagnose single and mixed infections in chickens. Three primer sets and composite probes were designed according to the conserved regions of the NS gene of ChPV, VP1 gene of CIAV and hexon gene of FAdV-4. Each composite probe was labelled with a different fluorophore, which was detached to release the fluorescence signal after amplification. The target viruses were distinguished based on the colour of the mLAMP products. The mLAMP assay was shown to be sensitive, with detection limits of 307 copies of recombinant plasmids containing the ChPV target genes, 749 copies of CIAV and 648 copies of FAdV-4. The assay exhibited good specificity and no cross-reactivity with other symptomatically related avian viruses. When used on field materials, the results of the mLAMP assay were in 100% agreement with those of the previously published PCR assay. The mLAMP assay is rapid, economical, sensitive and specific, and the results of amplification are directly observable by eye. Therefore, the mLAMP assay is a useful tool for the clinical detection of ChPV, CIAV and FAdV-4 and can be applied in rural areas.

A point-of-care dot blot ELISA assay for detection of protective antibody against canine adenovirus, canine parvovirus, and canine distemper virus is diagnostically accurate.

OBJECTIVE: To determine diagnostic accuracy of a point-of-care antibody-screening test by determining sensitivity, specificity, and overall accuracy when compared to reference standard tests for antibody against core vaccine viruses canine adenovirus (CAV), canine parvovirus (CPV), and canine distemper virus (CDV). A further aim was to provide the practitioner with information to guide selection of vaccinal antibody testing methods. SAMPLES: Canine sera from across North America were submitted to a fee-for-service titer-testing laboratory. Samples came from healthy pet dogs with known core vaccination history (n = 431) as well as unvaccinated dogs held in isolation (132). This study examined a total of 563 samples for CDV/CPV and 183 for CAV. PROCEDURES: Serum virus neutralization assays determined antibody titers for CDV and CAV. Hemagglutination inhibition assay determined antibody titers against CPV. All sera were also tested by point-of-care dot blot ELISA (index test). RESULTS: For all 3 viral antigens, the index test provided sensitivity ranging from 96.03% to 96.75% and specificity ranging from 87.50% to 94.33%. Overall accuracy ranged from 93.43% to 95.91%. CLINICAL RELEVANCE: The index test correlates well with reference standard tests and is a reliable, rapid screening test for detection of protective vaccinal antibody against CAV, CDV, and CPV in healthy dogs over 20 weeks of age. An accurate assessment of immunity allows clinicians to administer core vaccines appropriately as needed, avoiding unnecessary risk of adverse vaccine events.

Parvovirus B19-triggered hemophagocytic lymphohistiocytosis in a patient with Crohn's disease.

Background: Hemophagocytic lymphohistiocytosis (HLH) is a life threatening condition caused by inappropriate immune activity. Infection is often the trigger, both in genetically predisposed and in sporadic cases. Although more commonly seen in the paediatric population, patients of all ages can be affected. Case presentation: A 26-year-old male patient with Crohn's disease, treated with ustekinumab, presented with high fever, epistaxis and anorexia. Laboratory results showed pancytopenia, and a high serum levels of ferritin and LDH. Colonoscopy revealed only mild signs of disease activity. CT-scan showed splenomegaly and multiple lymphadenopathies. Bone marrow aspirate was suggestive for hemophagocytosis. PCR & serology for parvovirus B19 came back positive. Treatment with ustekinumab was temporarily put on hold and supportive care was given. Viral replication decreased and he recovered completely. Conclusion: There is a known association between HLH and Crohn's disease. This is probably because they are more susceptible to infections with CMV, EBV and parvovirus B19, all known as triggers for HLH. The role of ustekinumab is unclear: did it play a role in the pathophysiological evolution of this primo-infection with parvovirus B19? On the other hand, did it contribute to the rather mild course of the disease, acting as a immunomodulator that works on interleukin-12, a cytokine that plays a role in HLH? Further study is warranted to answer these questions.

Case Report: Bocavirus Infection Radiologically Resembling a Congestive Heart Failure in a Patient with Metastatic Castration-Resistant Prostate Cancer.

Background: Human bocavirus (HBoV) is a viral pathogen from the genus Bocaparvovirus (family Parvoviridae, subfamily Parvovirinae) discovered in 2005. Most of available literature is about HBoV in children and adults with hematological malignancies and in otherwise healthy children with respiratory infections. Information regarding infection in the adult population with solid tumors is scarce. Case Report: We report the case of a 51-year-old male with metastatic castration resistant prostate cancer undergoing chemotherapy treatment who presented with fever, dyspnea, dry cough, and pleuritic pain. Imaging techniques showed signs of congestive heart failure. Symptoms, laboratory tests and echocardiography revealed a more probable infectious etiology. Antibiotic therapy was started. A polymerase chain reaction (PCR) test of nasopharyngeal exudate for respiratory viruses was positive for HBoV. The rest of the microbiological tests were negative. Bronchoalveolar lavage (BAL) was performed. Bacterial culture of BAL was negative while respiratory virus PCR confirmed positivity for HBoV. Antibiotic therapy was discontinued. The patient gradually recovered. Conclusions: Emerging infectious diseases are a notorious threat for immunocompromised populations such as solid tumor patients. This case is unique because to our knowledge this is the first case report article of HBoV in a solid tumor patient and because imaging techniques exhibited signs of congestive heart failure that did not correlate with the rest of the tests. It shows that unusual pathogens should be considered when managing serious clinical complications with uncommon presentations in cancer patients. Notable diagnostic efforts should be made to reach a diagnosis in these cases.

Evaluation of Molecular Test for the Discrimination of "Naked" DNA from Infectious Parvovirus B19 Particles in Serum and Bone Marrow Samples.

Low levels of parvovirus B19 (B19V) DNA can be detected in the circulation and in different tissue of immunocompetent individuals for months or years, which has been linked to inflammatory diseases such as cardiomyopathy, rheumatoid arthritis, hepatitis, and vasculitis. However, the detection of B19V DNA does not necessarily imply that infectious virions are present. This study aimed to evaluate the method based on the Benzonase® treatment for differentiation between the infectious virions from "naked" DNA in serum and bone marrow (BM) samples to be useful for the B19V routine diagnosis. In addition, we estimated the period of viremia and DNAemia in the sera and bone marrow of nonhuman primates experimentally infected with B19V. Serum samples from ten patients and from four cynomolgus monkeys experimentally infected with B19V followed up for 60 days were used. Most of the human serum samples became negative after pretreatment; however, only decreased viral DNA loads were observed in four patients, indicating that these samples still contained the infectious virus. Reduced B19V DNA levels were observed in animals since 7th dpi. At approximately 45th dpi, B19V DNA levels were below 105 IU/mL after Benzonase® pretreatment, which was not a consequence of active B19V replication. The test based on Benzonase® pretreatment enabled the discrimination of "naked DNA" from B19V DNA encapsidated in virions. Therefore, this test can be used to clarify the role of B19V as an etiological agent associated with atypical clinical manifestations.

Adult acute respiratory distress syndrome due to human parvovirus B19 infection after cardiac surgery: a case report.

BACKGROUND: Infection with human parvovirus B19 (PB19) is very common in pediatric patients. Symptoms and signs depend on the infected patient's immune and hematopoietic status and can range from an asymptomatic condition to life-threatening disease. CASE PRESENTATION: A 69-year-old man received elective mitral valvular replacement and tricuspid valvuloplasty under cardiopulmonary bypass and suffered acute respiratory distress syndrome on postoperative day 8. Through the detection of positive serum IgM and human PB19-specific nucleic acids in serum and bronchoalveolar lavage fluid via metagenomic next-generation sequencing (mNGS), acute human PB19 infection was confirmed. The patient was ventilated and the pulmonary infiltration was attenuated six days later. CONCLUSION: A combination of serum human PB19 DNA by mNGS and positive serum human PB19 IgM could provide higher diagnostic sensitivity for acute human PB19 infection. The method of mNGS may be a new choice for detecting rare or atypical pathogens in severe complicated pneumonia. The infection of human PB19 was possibly self-limited.

Algorithm for laboratory diagnostics of parvoviral infection in risk groups.

Parvovirus infection (PVI) is widespread, characterized by airborne, bloodborne and vertical transmission routes. Parvovirus B19 (PVB19) exhibits tropism to erythropoietic cells. According to the increased likelihood principle of PVB19 infection and the severity of the consequences, immunocompromised individuals, especially those with hematological manifestations of diseases, are in increased risk group. Based on the own research results and analysis of the published data, we have proposed specific algorithms for PVI laboratory testing in individual risk groups, taking into account the peculiarities of the development and infection manifestation in each group: in HIV-infected patients, in oncohematological patients with to whom allogeneic hematopoietic stem cell transplantation (allo-HSCT) have been prescribed (blood and bone marrow recipients), as well as in patients with chronic anemia of parasitic etiology. For each group, the main clinical or laboratory marker, treatment procedure, or patient physiological parameters have been determined, based on which it was recommended to test for PVI. For HIV-infected patients, the main criterion for PVI testing is persistent anemia. For oncohematological patients, the basis for PVI testing is allo-HSCT procedure, which is planned or performed for this particular patient. For malaria patients, the patient's age was considered as major criterion, since in malaria and PVI coinfected young children can lead to a fatal outcome. The proposed PVI diagnostics algorithms usein risk groups can help to predict the severe course of underlying disease associated with PVB19 infection, and timely correct the therapy used.

Parvovirus B19 myocarditis in children: a diagnostic and therapeutic approach.

Parvovirus B19 is one of the most frequent causes of pediatric myocarditis, associating high mortality rates or need for cardiac transplantation. The aim of this study is to describe the clinical course of Parvovirus B19 myocarditis in children with emphasis on the role of endomyocardial biopsy and cardiac magnetic resonance, and the use of an innovative therapeutic strategy. Eleven patients and 12 episodes of polymerase chain reaction (PCR)-confirmed Parvovirus B19 myocarditis were prospectively collected for 14 years. Diagnosis was confirmed either histopathologically or by magnetic resonance. A life-threatening clinical presentation is described, similar to previous series, but with 83.3% overall survival without transplantation. We also present a case of recurrent myocarditis, which is extraordinarily rare. Electrocardiographic patterns presented chiefly peaked p waves, low QRS voltages, and negative T waves on inferior or lateral leads. Endomyocardial biopsy is the gold standard diagnostic test; alternatively magnetic resonance could be a useful diagnostic tool. A good concordance between myocardial and blood PCRs was observed. Seven patients received treatment with corticosteroids and beta interferon and all underwent a significant cardiac function improvement. CONCLUSION: A severe clinical presentation is reported, similar to previous reports but with better outcomes. Endomyocardial biopsy is the gold standard diagnostic test; alternatively magnetic resonance may be used. Both blood and myocardium PCR can be used in children to establish the microbiological etiology. Steroids with IFNß could be a useful therapeutic option, although further multicenter studies are needed to confirm these results. WHAT IS KNOWN: • Parvovirus B19 is one of the most frequent causes of myocarditis in children. It is associated with a fulminant clinical presentation. • Endomyocardial biopsy is the gold standard diagnostic test but it is an invasive procedure. WHAT IS NEW: • Myocarditis may recur in pediatrics, even it is extraordinarily rare. • IFNß with steroids may be a useful therapeutic option to improve the outcomes.

Duodenal perforation in a puppy with canine parvovirus infection.

A 2-month-old puppy was brought to a veterinary hospital with diarrhea, vomiting, and anorexia. The test for canine parvovirus was positive, and she was hospitalized for supportive care. Her gastrointestinal symptoms initially improved; however, vomiting and lethargy developed again in the second week of hospitalization. Abdominal ultrasonography results were suspicious of a duodenal perforation. Cytology of the abdominal effusion confirmed septic peritonitis; therefore, emergency exploratory laparotomy was performed. The surgery was successful, and the puppy recovered fully. When symptoms recur or deteriorate in patients with parvoviral infection, surgically curable complications may be disregarded if supportive therapy is continued without additional investigative examinations. This report highlights the usefulness of abdominal ultrasound in conjunction with fluid cytology to identify subsequent complications when the clinical signs of parvovirus deteriorate. Key clinical message: This case report demonstrates duodenal perforation as a complication of parvoviral infection. Abdominal ultrasonography and peritoneal fluid cytology can be crucial for the early recognition of intestinal complications requiring immediate successful perioperative treatment.

Perforation duodénale chez un chiot infecté par le parvovirus canin. Un chiot de 2 mois a été amené dans un hôpital vétérinaire avec de la diarrhée, des vomissements et de l'anorexie. Le test de dépistage du parvovirus canin était positif et l'animal a été hospitalisé pour des soins de soutien. Ses symptômes gastro-intestinaux se sont initialement améliorés; cependant, des vomissements et une léthargie se sont à nouveau développés au cours de la deuxième semaine d'hospitalisation. Les résultats de l'échographie abdominale étaient suspects d'une perforation duodénale. La cytologie de l'épanchement abdominal a confirmé une péritonite septique; par conséquent, une laparotomie exploratrice d'urgence a été réalisée. L'opération a été un succès et le chiot s'est complètement rétabli. Lorsque les symptômes réapparaissent ou s'aggravent chez les patients atteints d'une infection parvovirale, les complications soignables chirurgicalement peuvent être ignorées si le traitement de soutien est poursuivi sans examens d'investigation supplémentaires. Ce rapport souligne l'utilité de l'échographie abdominale en conjonction avec la cytologie du liquide péritonéal pour identifier les complications ultérieures lorsque les signes cliniques associés au parvovirus se détériorent.Message clinique clé :Ce rapport de cas démontre une perforation duodénale comme complication d'une infection parvovirale. L'échographie abdominale et la cytologie du liquide péritonéal peuvent être cruciales pour la détection précoce des complications intestinales nécessitant un traitement per-opératoire immédiat réussi.(Traduit par Dr Serge Messier).

Hemophagocytic lymphohistiocytosis associated with parvovirus B19-induced aplastic crisis in a hereditary spherocytosis patient: A case report and literature review.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation. It occurs because of severe inflammation due to uncontrolled proliferation of activated lymphocytes and histiocytes, characterized by the production of excessive levels of cytokines. Virus-associated HLH is a well-known entity, and parvovirus B19 is one of the common causes. Parvovirus B19 can also affect blood cell lineages. Therefore, HLH may be accompanied by several diseases such as cytopenia, aplastic anemia, and myelodysplastic syndrome. Herein, we report the case of a patient with hereditary spherocytosis who was diagnosed with parvovirus B19-induced HLH and aplastic crisis. A 7-year-old girl presented to our hospital with fever, pleural effusion, pancytopenia, hepatosplenomegaly, and hypotension. A bone marrow biopsy was performed under the suspicion of HLH, which revealed hemophagocytes. The diagnostic criteria for HLH were met, and prompt chemoimmunotherapy was initiated considering the clinically unstable situation. Her health improved rapidly after initiating treatment. Further study revealed that she had hereditary spherocytosis, and parvovirus B19 had caused aplastic crisis and HLH. The patient's clinical progress was excellent, and chemoimmunotherapy was reduced and discontinued at an early stage. This case shows that aplastic crisis and HLH can coexist with parvovirus B19 infection in patients with hereditary spherocytosis. Although the prognosis was good in this case of HLH caused by parvovirus B19, early detection and active treatment are essential.