title: Outbreaks of human-herpes virus 6 (HHV-6) infection in day-care centers in Belém, Pará, Brazil.
abstract: A total of 730 children aged less than 7 years, attending 8 day-care centers (DCCs) in Belém, Brazil were followed-up from January to December 1997 to investigate the occurrence of human-herpes virus 6 (HHV-6) infection in these institutional settings. Between October and December 1997 there have been outbreaks of a febrile- and -exanthematous disease, affecting at least 15-20% of children in each of the DCCs. Both serum- and- plasma samples were obtained from 401 (55%) of the 730 participating children for the detection of HHV-6 antibodies by enzyme-linked immunosorbent assay (ELISA), and viral DNA amplification through the nested-PCR. Recent HHV-6 infection was diagnosed in 63.8% (256/401) of them, as defined by the presence of both IgM and IgG-specific antibodies (IgM+/IgG+); of these, 114 (44.5%) were symptomatic and 142 (55.5%) had no symptoms (p = 0.03). A subgroup of 123 (30.7%) children were found to be IgM-/IgG+, whereas the remaining 22 (5.5%) children had neither IgM nor IgG HHV-6- antibodies (IgM-/IgG-). Of the 118 children reacting strongly IgM-positive (> or = 30 PANBIO units), 26 (22.0%) were found to harbour the HHV-6 DNA, as demonstrated by nested-PCR. Taken the ELISA-IgM- and- nested PCR-positive results together, HHV-6 infection was shown to have occurred in 5 of the 8 DCCs under follow-up. Serological evidence of recent infections by Epstein-Barr virus (EBV) and parvovirus B19 were identified in 2.0% (8/401) and 1. 5% (6/401) of the children, respectively. Our data provide strong evidence that HHV-6 is a common cause of outbreaks of febrile/exanthematous diseases among children attending DCCs in the Belém area.
authors.affiliation: Serviço de Virologia Geral, Instituto Evandro Chagas, Fundação Nacional de Saúde, Ministério da Saúde, Belém, Pará, Brasil. ronaldo@iec.pa.gov.br
authors.forename: R B
authors.initials: RB
authors.lastname: Freitas
authors.forename: T A
authors.initials: TA
authors.lastname: Monteiro
authors.forename: A C
authors.initials: AC
authors.lastname: Linhares
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002648:Child; D002656:Child Day Care Centers / Q000706:statistics & numerical data*; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D004797:Enzyme-Linked Immunosorbent Assay; D005077:Exanthema Subitum / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D015654:Herpesvirus 6, Human; D006801:Humans; D007223:Infant; D008297:Male; D016133:Polymerase Chain Reaction