Parvovirus B19-associated fulminant acute myocarditis in children during the fifth disease outbreak in 2024: What should we learn?

Myocarditis is a significant cause of cardiac morbidity in children, with viral infections, including Parvovirus B19 (PVB19), among the most implicated agents. Recent epidemiological reports suggest a resurgence of PVB19 infections post-COVID-19, raising concerns about associated myocarditis. We aimed to retrospectively analyze clinical, laboratory, and imaging data of patients with PVB19-associated myocarditis in 2024. We included 5 pediatric patients admitted with acute myocarditis and positive blood PVB19-DNA. Median age was 6.4 years; 80% were male. Most patients presented with cardiogenic shock; two required extracorporeal membrane oxygenation. Echocardiography revealed severely reduced left ventricular ejection fraction (median 25%), atrial enlargement, and mitral insufficiency. No direct correlation was found between PVB19 DNA load and disease severity. Immunomodulatory therapy, including IVIG (intravenous immunoglobulin) and corticosteroids, was administered in most cases, with variable outcomes. Three patients had viral coinfections, raising concern for a potential link with worse outcomes. Following the SARS-CoV-2 pandemic, an apparent increase in pediatric myocarditis has been observed. The 2024 outbreak of PVB19 infections was associated with an unusual number of fulminant myocarditis cases, particularly in infants. However, our small sample precludes definitive conclusions. Larger multicenter studies are needed to clarify the role of PVB19 and coinfections in pediatric myocarditis.