title: Loss of maternally derived human herpesvirus-6 immunity and natural infection in Argentinian infants.
abstract: BACKGROUND
  Human herpesvirus-6 (HHV-6) infection is widespread throughout the world. No data are available in Argentina about the loss of maternally derived HHV-6 immunity and natural infection in infants.
  
  
  METHODS
  A population of 100 pregnant women and 407 children between 1 and 15 months of age were assayed by indirect immunofluorescence to detect and quantify specific IgG anti-human herpesvirus-6 (anti-HHV-6) antibodies in Córdoba City, Argentina.
  
  
  RESULTS
  There was no significant difference in the positive rate between infants aged 1 to 9 months (range, 43.6 35.5%) and pregnant women (37%). Seropositive ratio dropped in the 10-month group (23.33% seropositive) and rose sharply in the 11-month group (38.89%), 12-month (60.61%), and 13- to 15-month group (63.46%). The geometric mean titer (GMT) for infants in the 12 to 15 months age group (23.4 41.64) was significantly higher than the GMT for infants 10 months of age (11.04) (P < 0.05 with the Tukey-HSD test).
  
  
  CONCLUSIONS
  This study shows a significant association between loss of passive HHV-6 antibody and age among infants. The results support evidence that HHV-6 enters the susceptible population at 11 months, leading to a high prevalence of antibodies in children between 13 and 15 months of age.
authors.affiliation: School of Medical Sciences, National University of Córdoba, Argentina.
authors.forename: L A
authors.initials: LA
authors.lastname: Alessio
authors.forename: S E
authors.initials: SE
authors.lastname: Carricart
authors.forename: D
authors.initials: D
authors.lastname: Bustos
authors.forename: S V
authors.initials: SV
authors.lastname: Nates
authors.forename: H
authors.initials: H
authors.lastname: Gendelman
authors.forename: J V
authors.initials: JV
authors.lastname: Pavan
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000914:Antibodies, Viral / Q000097:blood; D001118:Argentina / Q000453:epidemiology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D015654:Herpesvirus 6, Human / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D007223:Infant; D008297:Male; D011247:Pregnancy; D015995:Prevalence; D012307:Risk Factors; D019349:Roseolovirus Infections / Q000097:blood / Q000453:epidemiology* / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral