The accuracy of anti-human herpesvirus 6 IgM detection in children with recent primary infection

Abstract

Human herpesvirus 6 (HHV-6) has been shown to infect almost all children by 4 years of age. Even with a typical clinical presentation, HHV-6 infection is misdiagnosed frequently as measles or rubella. The aim of this study was to assess the accuracy of the IgM test for detection of recent primary HHV-6 infection. The study was conducted between January, 1998 and December, 2006 at primary health care units in Niterói, Rio de Janeiro, Brazil. Sera from 185 children, in whom measles, rubella, dengue fever and parvovirus B19 infections were excluded, were studied for anti-HHV-6 IgG and IgM antibodies using an indirect immunofluorescence test. Seventy-one (38.4%) of the children had evidence of primary HHV-6 infection. Taking the IgG avidity test as the “gold standard”, the following results for IgM were obtained—sensitivity: 76.1%; specificity: 87.5%; accuracy: 82.4%. This study confirmed the low accuracy of IgM detection for the diagnosis of primary HHV-6 infection.