title: Diagnosis of infectious mononucleosis caused by Epstein-Barr virus in infants.
abstract: BACKGROUND
  The diagnosis of infectious mononucleosis (IM) is usually on serologic tests. The responses of anti-Epstein-Barr virus (anti-EBV) antibodies are weak in infants. The authors encountered some IM infants in whom anti-EBV antibodies were undetectable during early stage, although EBV genome was found in their blood. The aim of the present study was therefore to clarify the frequency of anti-EBV-antibody negative IM cases.
  
  
  METHODS
  The EBV serostatus of 104 IM children diagnosed on Sumaya criteria was retrospectively studied. The EBV genome in peripheral blood mononuclear cells was measured.
  
  
  RESULTS
  The anti-viral capsid antigen-IgM (anti-VCA-IgM)-positive rate in the acute phase was only 25% in infants but 80% in patients ≥ 4 years of age. Twenty percent of the infants were negative for all anti-EBV antibodies and required repeated serologic tests. For infants, the significant rise in anti-VCA-IgG was the most sensitive marker. Three seronegative infants with IM symptoms, with circulating EBV genome during acute phase, were eventually considered as having IM on anti-VCA-IgG seroconversion thereafter.
  
  
  CONCLUSIONS
  To diagnose IM in infants the serologic test alone in the acute phase is not sensitive enough. It is proposed that the EBV genome be evaluated in peripheral blood mononuclear cells when infants presenting with IM symptoms are negative for anti-EBV antibodies during the acute phase.
authors.affiliation: Department of Pediatrics, Kochi Medical School, National University Corporation Kochi University, Okoh-cho, Nankoku, Japan.
authors.forename: Sumitaka
authors.initials: S
authors.lastname: Dohno
authors.forename: Akihiko
authors.initials: A
authors.lastname: Maeda
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Ishiura
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sato
authors.forename: Mikiya
authors.initials: M
authors.lastname: Fujieda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wakiguchi
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology; D036022:Capsid Proteins / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D007244:Infectious Mononucleosis / Q000175:diagnosis*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; D019309:Epstein-Barr Virus Nuclear Antigens; C041788:Epstein-Barr viral capsid antigen; D007074:Immunoglobulin G; D007075:Immunoglobulin M