Fatal parvovirus myocarditis in a 5-year-old girl

Infection with parvovirus B19 is common in children and typically causes mi ld illness, We report here the case of a g-year-old girl who died suddenly, 2 weeks after the clinical diagnosis of a parvoviral infection (erythema i nfectiosum), Microscopic examination of the heart showed severe myocarditis with extensive T-cell and macrophage infiltration. Cultures, serology, and molecular analyses of serum for enteroviridae, adenovirus, influenza, vari cella tester, cytomegalovirus, and herpes simplex viruses were negative. Qu antitative polymerase chain reaction (PCR) analysis for parvovirus B19 in p eripheral blood, however, showed active infection (91,000 genomes/mL serum; 2.4 genomes/mononuclear cell), Despite the presence of myocarditis, immuno staining for parvoviral surface antigens was negative in the heart. Quantit ative PCR analysis of paraffin sections showed that myocardial parvoviral c ontent was significantly less than that of the normal appearing kidney and within the range predicted simply by tissue blood content. Thus, parvovirus B19 infection can be complicated by fatal myocarditis, Because the virus d oes not appear to have infected the heart, per se, we speculate that myocar ditis arose from immunological cross-reaction to epitopes shared between th e virus and the myocardium. HUM PATHOL 32: 342-345, Copyright (C) 2001 by W .B. Saunders Company.