Histologic and in situ viral findings in the myocardium in cases of sudden, unexpected death

The purpose of this study was to do in situ viral detection in myocardial tissues of individuals who suffered sudden unexpected death and to correlate the results with the postmortem histopathologic findings. Thirteen cases were identified and the heart tissues were analyzed for adenovirus, cytomegalovirus, Epstein Barr virus, herpes simplex virus 1 and 2, human immunodeficiency virus 1 (HIV-1), influenza A, influenza B, parvovirus, rotavirus, picornavirus (including separate primers for enterovirus and Coxsackie virus A and B), varicella zoster virus, and respiratory syncytial virus. Thirteen individuals aged 2 to 67 years were studied. In each case, polymerase chain reaction-amplified viral RNA was detected in situ: Coxsackie virus B (5 cases), rotavirus (4 cases), HIV-1 (2 cases), influenza A (1 case), and influenza B (1 case). Immunohistochemical detection of viral proteins was found in the five Coxsackie virus cases and four rotavirus cases. The mononuclear inflammatory infiltrate was diffuse and marked only in the cases of influenza A and HIV-1, as well as one of the Coxsackie virus and rotavirus cases, respectively. Immunohistochemical analysis showed that the most common cell type in the inflammatory infiltrates was CD68-positive macrophages. Direct myocyte infection was most prominent in the cases of Coxsackie virus infection. In summary, in situ viral detection was documented in each case of idiopathic myocarditis associated with sudden, unexpected death; in 6/13 cases, the myocarditis was focal and minimal. Although Coxsackie virus was, as expected, the most common virus noted, other viruses including rotavirus and HIV-1 were also observed, highlighting the need for comprehensive viral and histologic analyses in such cases.