title: Detection of human herpesvirus 7 infection in young children presenting with exanthema subitum.
abstract: In this study, we assessed the prevalence of human herpesvirus-7 (HHV-7) in 141 serum samples from children less than four years of age with exanthematic disease. All samples were negative for measles, rubella, dengue fever and parvovirus B19 infection. Testing for the presence of human herpesvirus-6 (HHV-6)-specific high avidity IgG antibodies by indirect immunofluorescence assay (IFA) revealed two main groups: one composed of 57 patients with recent primary HHV-6 infection and another group of 68 patients showing signs of past HHV-6 infection. Another 16 samples had indeterminate primary HHV-6 infection, by both IgG IFA and IgM IFA. Serum samples were subjected to a nested polymerase chain reaction to detect the presence of HHV-7 DNA. Among patients with a recent primary HHV-6 infection, HHV-7 DNA was present in 1.7% of individuals; however, 5.8% of individuals tested positive for HHV-7 DNA in the group with past primary HHV-6 infection. Among the 16 samples with indeterminate diagnosis, 25% (4/16) had HHV-7 DNA (p < 0.002). We hypothesise that HHV-7 might be the agent that causes exanthema. However, a relationship between clinical manifestations and the detection of virus DNA does not always exist. Therefore, a careful interpretation is necessary to diagnose a primary infection or a virus-associated disease. In conclusion, we detected HHV-7 DNA in young children from the state of Rio de Janeiro, Brazil.
authors.affiliation: Laboratório 319, Departamento de Microbiologia e Parasitologia, Universidade Federal Fluminense, Niterói, RJ, Brasil.
authors.forename: Ivna de Melo
authors.initials: Ide M
authors.lastname: Magalhães
authors.forename: Rebeca Vazquez Novo
authors.initials: RV
authors.lastname: Martins
authors.forename: Renata Oliveira
authors.initials: RO
authors.lastname: Vianna
authors.forename: Natalia
authors.initials: N
authors.lastname: Moysés
authors.forename: Larissa Alves
authors.initials: LA
authors.lastname: Afonso
authors.forename: Solange Artimos
authors.initials: SA
authors.lastname: Oliveira
authors.forename: Silvia Maria Baeta
authors.initials: SM
authors.lastname: Cavalcanti
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D004279:DNA, Viral / Q000032:analysis*; D005077:Exanthema Subitum / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D016199:Herpesvirus 7, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D016133:Polymerase Chain Reaction; D015995:Prevalence
chemical_list: D004279:DNA, Viral