title: Behavioral, virologic, and immunologic factors associated with acquisition and severity of primary Epstein-Barr virus infection in university students.
abstract: BACKGROUND
  University students were studied prospectively to determine the incidence of and risk factors for acquisition of primary Epstein-Barr virus (EBV) infection and the virologic and immune correlates of disease severity.
  
  
  METHODS
  EBV antibody-negative freshmen participated in monthly surveillance until graduation. If antibodies developed, proximate samples were assayed for viral load by polymerase chain reaction. Lymphocyte and natural killer (NK) cell numbers and activation were measured by flow cytometry, and plasma cytokine levels were measured by a multiplex assay.
  
  
  RESULTS
  Of 546 students screened, 202 (37%) were antibody negative; 143 antibody-negative students were enrolled. During a median of 3 years of observation, 66 subjects experienced primary infection. Of these, 77% had infectious mononucleosis, 12% had atypical symptoms, and 11% were asymptomatic. Subjects reporting deep kissing with or without coitus had the same higher risk of infection than those reporting no kissing (P < .01). Viremia was transient, but median oral shedding was 175 days. Increases were observed in numbers of NK cells and CD8(+) T-cells but not in numbers of CD4(+) T-cells during acute infection. Severity of illness correlated positively with both blood EBV load (P = .015) and CD8(+) lymphocytosis (P = .0003).
  
  
  CONCLUSIONS
  Kissing was a significant risk for primary EBV infection. A total of 89% of infections were symptomatic, and blood viral load and CD8(+) lymphocytosis correlated with disease severity.
authors.affiliation: Department of Laboratory Medicine and Pathology, School of Public Health, University of Minnesota Medical School, Minneapolis 55455, USA. balfo001@umn.edu
authors.forename: Henry H
authors.initials: HH
authors.lastname: Balfour
authors.forename: Oludare A
authors.initials: OA
authors.lastname: Odumade
authors.forename: David O
authors.initials: DO
authors.lastname: Schmeling
authors.forename: Beth D
authors.initials: BD
authors.lastname: Mullan
authors.forename: Julie A
authors.initials: JA
authors.lastname: Ed
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Knight
authors.forename: Heather E
authors.initials: HE
authors.lastname: Vezina
authors.forename: William
authors.initials: W
authors.lastname: Thomas
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Hogquist
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000097:blood; D004279:DNA, Viral / Q000097:blood; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D007244:Infectious Mononucleosis / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission / Q000821:virology; D053208:Kaplan-Meier Estimate; D007694:Killer Cells, Natural / Q000276:immunology; D008218:Lymphocytosis / Q000276:immunology; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D018571:Sentinel Surveillance; D012720:Severity of Illness Index; D013334:Students; D014495:Universities; D019562:Viral Load; D014766:Viremia; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D016207:Cytokines; D004279:DNA, Viral