Fatal parvovirus B19 myocarditis in children and possible dysimmune mechanism

Virological characterization of Parvovirus B19 isolated during the atypical 2023-2024 outbreak in France

BACKGROUND

A Parvovirus B19 (B19V) outbreak has been reported in Europe in 2023-2024. The aims of this study were 1) to describe the incidence of primary cases from 2012 to 2024 in one French hospital 2) to analyze the genome of 2023 strains 3) to identify virological profiles according to the clinical presentations of B19V infection.

METHODS

The incidence of B19V primary cases was studied through an interrupted time-series analysis. Genomes of 2023 strains were sequenced in the NS1-VP1u region. Blood viral loads, IgG and IgM levels were analyzed in 158 cases according to clinical manifestations with Kruskal-Wallis test and a machine learning approach based on k-nearest neighbors.

RESULTS

During the 2023-2024 B19V outbreak, there was an 8-time increase in the incidence of B19V infections compared with pre-pandemic levels (8.25 (95%CI: 5.79-11.76)). The 2023 strains belonged to genotype 1a and were closely related to pre-2019 strains. Blood viral loads were significantly different between clinical presentations (p<0.0001). Machine learning allowed us to classify 68.8% (95% CI: 60.9-75.9) patients into the correct clinical group.

CONCLUSIONS

The 2023-24 epidemic is probably due to the reemergence of the pre-2019 strain. The virological profiles highlighted in this study could assist in accurately interpreting virology results.

Cardiac arrhythmias in viral infections

BACKGROUND

The current COVID-19 pandemic has led to many studies examining its arrhythmogenic effects. However, there are many other viruses that are capable of inducing arrhythmias that have not received as much attention. The objective of this study was to review common viruses and identify studies highlighting their arrhythmogenic effects.

METHODS AND RESULTS

In this review, we examined 15 viruses and the literature regarding their arrhythmogenic effects. The common mechanisms of action appear to be direct invasion of myocytes leading to immune mediated damage, infection of vascular endothelium, and alteration of cardiac ion channels.

CONCLUSIONS

This review highlights the growing evidence that supports the involvement of other viral infections in the development of arrhythmia. Physicians should be aware of these potentially life-threatening effects when caring for patients with these viruses, some of which are very common. Additional studies are required to better understand the complex mechanism and risk factors of cardiac arrhythmias in patients suffered from viral infections to determine whether the processes can be reversed or even prevented.

Parvovirus B19-Associated Myocarditis: A Literature Review of Pediatric Cases

Parvovirus B19 (B19V) infection may lead to myocarditis, a life-threatening condition in pediatric patients. In this review, we aim to present published pediatric cases of B19V-associated myocarditis in order to understand the deep complex connections and draw useful conclusions. We performed a comprehensive search of MEDLINE, Science Direct, and Google Scholar electronic databases. A total of 32 cases were included in our study. The most common presenting symptom was tachycardia in 22/32 patients (68.7%), followed by tachypnoea (21/32, 65.6%), fever, and rash (12/32, 37.5% for both of them). Cardiac arrest, loss of consciousness, and systemic infection were associated with the worst prognosis, with statistically significant differences (p-value 0.001, 0.02, 0.001. respectively). A percentage as high as 90.4% of patients with left ventricular (LV) dysfunction and reduced ejection fraction (EF) were discharged. Twelve patients required ventilatory support, five required extracorporeal membrane oxygenation (ECMO), and three underwent heart surgery. Treatment with immunosuppressive agents and immunoglobulin was found to be beneficial for patients (p-value 0.006 and 0.004, respectively). In conclusion, B19V myocarditis has high mortality rates in children. There is no specific antiviral treatment for B19V infection and therapeutic strategies for myocarditis aim to delay the worsening of heart failure and to preserve the LV function. Inotropic drugs, diuresis, ventilatory support, Intravenous immunoglobulin (IVIG), and immunosuppressive therapy seem to help the recovery of the myocardium in children with LV dilation, dysfunction, and reduced EF. Children with cardiac arrest, arrhythmias, and loss of consciousness have the worst prognosis.

Fatal parvovirus B19 infections: a report of two autopsy cases

Parvovirus B19 (PVB19) commonly infects children and is usually asymptomatic. Lethal outcomes of PVB19 infection are unusual; nevertheless, the two cases reported here are rare examples of PVB19-induced hemophagocytic syndrome and myocarditis in infants and children. The two cases show the indisputable usefulness of immunohistochemistry and in situ hybridization in the detection of PVB19. In the death investigations, histopathological examinations provided stronger evidence than did serology or molecular biology. The cases also highlight the importance of forensic autopsy in vaccine-related death. As vaccine-related deaths are what people fear and may cause declines in vaccination rates, it is important to clarify deaths temporally or causally associated with vaccine administration.

Post-mortem microbiology in sudden death: sampling protocols proposed in different clinical settings

BACKGROUND

Autopsies, including minimally invasive autopsies, are a powerful tool for determination of the cause of death. When a patient dies from an infection, microbiology is crucial to identify the causative organism. Post-mortem microbiology (PMM) aims to detect unexpected infections causing sudden deaths; confirm clinically suspected but unproven infection; evaluate the efficacy of antimicrobial therapy; identify emergent pathogens; and recognize medical errors. Additionally, the analysis of the thanatomicrobiome may help to estimate the post-mortem interval.

AIMS

The aim was to provide advice in the collection of PMM samples and to propose sampling guidelines for microbiologists advising autopsy pathologists facing different sudden death scenarios.

SOURCES

A multidisciplinary team with experts in various fields of microbiology and autopsies on behalf of the ESGFOR (ESCMID - European Society of Clinical Microbiology and Infectious Diseases - study group of forensic and post-mortem microbiology and in collaboration with the European Society of Pathology) developed this narrative review based on a literature search using MedLine and Scopus electronic databases supplemented with their own expertise.

CONTENT

These guidelines address measures to prevent sample contamination in autopsy microbiology; general PMM sampling technique; protocols for PMM sampling in different scenarios and using minimally invasive autopsy; and potential use of the evolving post-mortem microbiome to estimate the post-mortem interval.

IMPLICATIONS

Adequate sampling is paramount to identify the causative organism. Meaningful interpretation of PMM results requires careful evaluation in the context of clinical history, macroscopic and histological findings. Networking and closer collaboration among microbiologists and autopsy pathologists is vital to maximize the yield of PMM.

Myocarditis in Paediatric Patients: Unveiling the Progression to Dilated Cardiomyopathy and Heart Failure

Myocarditis is a challenging and potentially life-threatening disease associated with high morbidity in some paediatric patients, due to its ability to present as an acute and fulminant disease and to ultimately progress to dilated cardiomyopathy. It has been described as an inflammatory disease of the myocardium caused by diverse aetiologies. Viral infection is the most frequent cause of myocarditis in developed countries, but bacterial and protozoal infections or drug hypersensitivity may also be causative agents. The prompt diagnosis in paediatric patients is difficult, as the spectrum of clinical manifestation can range from no myocardial dysfunction to sudden cardiac death. Recent studies on myocarditis pathogenesis have revealed a triphasic nature of this disease, which influences the diagnostic and therapeutic strategies to adopt in each patient. Endomyocardial biopsy remains the gold standard for diagnosing myocarditis, and several non-invasive diagnostic tools can be used to support the diagnosis. Intravenous immunoglobulin has become part of routine practice in the treatment of myocarditis in paediatric patients at many centres, but its true effect on the cardiac function has been the target of many studies. The aim of this review is to approach the recently discovered facets of paediatric myocarditis regarding its progression to dilated cardiomyopathy.

The effects of co-infection with human parvovirus B19 and Plasmodium falciparum on type and degree of anaemia in Ghanaian children

OBJECTIVE

To determin the extent to which parvovirus B19 (B19V) and co-infection of B19V and malaria contribute to risk of anaemia in children.

METHODS

B19V DNA and malaria parasites were screened for 234 children at the PML Children's Hospital in Accra. The role of B19V and co-infection with B19V and malaria in anaemia was evaluated by analysing full blood cell counts, malaria and B19V DNA results from these children.

RESULTS

The prevalence of B19V, malaria and co-infection with B19V and malaria was 4.7%, 41.9% and 2.6%, respectively. Malaria posed a greater risk in the development of mild anaemia compared to severe anaemia (OR=5.28 vrs 3.15) whereas B19V posed a higher risk in the development of severe anaemia compared to mild anaemia (OR=4.07 vrs 1.00) from a non-anaemic child. Persons with co-infection with B19V and malaria had 2.23 times the risk (95% CI=0.40-12.54) of developing severe anaemia should they already have a mild anaemia. The degree of anaemia was about three times affected by co-infection (Pillai's trace=0.551, P=0.001) as was affected by malaria alone (Pillai's trace=0.185, P=0.001). B19V alone did not significantly affect the development of anaemia in a non-anaemic child. Microcytic anaemia was associated with B19V and co-infection with B19V and malaria more than normocytic normochromic anaemia.

CONCLUSIONS

B19V was associated with malaria in cases of severe anaemia. The association posed a significant risk for exacerbation of anaemia in mild anaemic children. B19V and co-infection with B19V and malaria may be associated with microcytic anaemia rather than normocytic normochromic anaemia as seen in cases of B19V infection among persons with red cell abnormalities.

Successful immunotherapy in life-threatening parvovirus B19 infection in a child

We report a case of an immunocompetent child who developed parvovirus B19 infection complicated by autoinflammatory disease with myocarditis, tamponade and macrophage activation syndrome. He recovered with immunotherapy including prednisone, immunoglobulins, cyclosporin and anakinra (anti-interleukin-1). The report shows that parvovirus can provoke severe systemic inflammation with acute heart injury and that anti-interleukin-1 might be considered in such parvovirus-related inflammation.

Immunomodulatory effects of mesenchymal stromal cells revisited in the context of inflammatory cardiomyopathy

Myocarditis is a common inflammatory cardiomyopathy, associated with cardiomyocyte apoptosis, which can lead to chronic left ventricular dysfunction. Under conventional heart failure therapy, inflammatory cardiomyopathy typically has a progressive course, indicating a need for alternative therapeutic strategies to improve long-term outcomes. Experimental and clinical studies consistently support the application of cellular transplantation as a strategy to improve myocardial function. Mesenchymal stromal cells (MSCs) mediate distinct paracrine effects supporting endogenous regeneration, but most important are their remarkable immunoregulatory properties. In this review, an overview of current knowledge on immunopathology in myocarditis will be given. Furthermore, current research regarding the immunomodulatory properties of MSCs in the context of myocarditis will be discussed. Finally, the impact of MSC priming by the environment on their functionality and the advantages of systemic administration of MSCs under myocarditis are outlined.

Parvovirus B19 myocarditis causes significant morbidity and mortality in children

Although parvovirus B19 (PVB19) currently is the most common cause of viral myocarditis, limited pediatric data exist. Whereas other viruses infect cardiomyocytes, PVB19 targets coronary endothelium, leading to myocardial ischemia and dysfunction. A retrospective review investigated patients with polymerase chain reaction (PCR)-verified PVB19 myocarditis at Texas Children's Hospital and Arkansas Children's Hospital (January 2005 to August 2008). The primary end points of the study were transplant-free survival and circulatory collapse (death, mechanical support, or transplantation). For the 19 patients identified (age, 6 months to 15 years), the most common presenting symptoms were respiratory and gastrointestinal. At admission, all the patients demonstrated ventricular dysfunction requiring inotropic support (median ejection fraction, 24 %; median left ventricle end-diastolic diameter [LVEDD] z-score, 4.6). Whereas T-wave abnormalities were common, ST elevation was evident in five patients (two died and three required transplantation). Serum B-type natrietic peptide was elevated in all 12 patients tested (range, 348-8,058 pg/ml), and troponin I was high in 7 of 9 patients (range, 0.04-14.5 ng/ml). Of the 15 patients with circulatory collapse, nine received mechanical support, eight underwent successful transplantation, and five died. Only six patients (32 %) experienced transplant-free survival, and five patients had full recovery of function at discharge. In the transplant-free survival group, ST changes on presenting electrocardiography were less likely (p = 0.03), and the admission LVEDD z-score tended to be lower (3.3 vs 5.6; p = 0.08). In children, PVB19 myocarditis causes significant mortality and morbidity. Although mechanical intervention can support patients in the initial stage of decompensated heart failure, patients with PVB19 myocarditis often demonstrate persistent dysfunction requiring medical therapy and transplantation.