title: A study of risk factors for acquisition of Epstein-Barr virus and its subtypes.
abstract: BACKGROUND
  Risk factors for primary infection with Epstein-Barr virus (EBV) and its subtypes have not been fully investigated.
  
  
  METHODS
  Questionnaires and serum samples from a total of 2006 students who entered Edinburgh University in 1999-2000 were analyzed to examine risk factors for EBV seropositivity, both overall and by EBV type.
  
  
  RESULTS
  The prevalence of EBV seropositivity was significantly increased among females, older students, those who had lived in tropical countries, those with siblings, and those who were sexually active, particularly if they had had numerous sex partners. Risk was lower (1) among students who always used a condom than among those who had sexual intercourse without one and (2) among female oral-contraceptive users than among sexually active nonusers. Risk factors for type 1 EBV infection were similar to those for EBV overall. No associations were found between nonsexual risk factors and type 2 infection. Sexual activity increased the risk of type 2 infection, but the increase in risk with number of sex partners was less consistent than for type 1 infections. Dual infection was uncommon, but the patterns of risk appeared to be similar to those of type 1 infection.
  
  
  CONCLUSIONS
  This study provides further evidence that EBV may be sexually transmitted and some suggestion that the risk factors for type 1 and type 2 infection differ.
authors.affiliation: Section of Epidemiology, Institute of Cancer Research, Surrey, SM2 5NG, United Kingdom. craig.higgins@icr.ac.uk
authors.forename: Craig D
authors.initials: CD
authors.lastname: Higgins
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Swerdlow
authors.forename: Karen F
authors.initials: KF
authors.lastname: Macsween
authors.forename: Nadine
authors.initials: N
authors.lastname: Harrison
authors.forename: Hilary
authors.initials: H
authors.lastname: Williams
authors.forename: Karen
authors.initials: K
authors.lastname: McAulay
authors.forename: Ranjit
authors.initials: R
authors.lastname: Thomas
authors.forename: Stuart
authors.initials: S
authors.lastname: Reid
authors.forename: Margaret
authors.initials: M
authors.lastname: Conacher
authors.forename: Kathryn
authors.initials: K
authors.lastname: Britton
authors.forename: Dorothy H
authors.initials: DH
authors.lastname: Crawford
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001769:Blood / Q000821:virology; D020031:Epstein-Barr Virus Infections / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*; D005260:Female; D005843:Geography; D004854:Herpesvirus 4, Human / Q000145:classification*; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012737:Sex Factors; D012725:Sexual Behavior; D015229:Sexually Transmitted Diseases, Viral / Q000821:virology*; D011795:Surveys and Questionnaires