title: High frequency of co-infection by Epstein-Barr virus types 1 and 2 in patients with multiple sclerosis.
abstract: BACKGROUND
  The existence of Epstein-Barr virus (EBV) strains specifically associated with multiple sclerosis (MS) is a matter of controversy. Little is also known about the prevalence of EBV types 1 and 2 in MS patients and the presence of co-infections by both strains.
  
  
  OBJECTIVE
  To make EBV strain type assignment and compare the frequencies of types 1, 2 and co-infections by both in MS patients and healthy controls.
  
  
  METHODS
  Blood samples from 75 consecutive MS patients and 186 controls were collected. EBV was simultaneously detected and typed using a polymerase chain reaction (PCR) which amplified a strain-specific sequence in the EBV nuclear antigen 2.
  
  
  RESULTS
  EBV was detected in 70 out of 75 patients (93.3%) and in 123 of 186 controls (66.1%). Among positive cases, type 1 was found in 6 patients (8.6%) and 40 controls (32.5%), type 2 in 1 patient (1.4%) and 37 controls (30.1%), and dual-infections by both EBV types were detected in 63 patients (90%) and 46 controls (37.4%). Logistic regression models showed that MS was significantly associated with the presence of EBV (p < 0.001) and also with dual type infections (p < 0.001).
  
  
  CONCLUSIONS
  This study provides molecular evidence associating co-infection of type 1 and 2 EBV with MS.
authors.affiliation: Department of Pathology, Ramón y Cajal University Hospital, IRYCIS, Madrid, Spain. asanton.hrc@salud.madrid.org
authors.forename: Almudena
authors.initials: A
authors.lastname: Santón
authors.forename: Eva
authors.initials: E
authors.lastname: Cristóbal
authors.forename: María
authors.initials: M
authors.lastname: Aparicio
authors.forename: Ana
authors.initials: A
authors.lastname: Royuela
authors.forename: Luisa M
authors.initials: LM
authors.lastname: Villar
authors.forename: José C
authors.initials: JC
authors.lastname: Alvarez-Cermeño
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D060085:Coinfection; D004279:DNA, Viral / Q000097:blood; D020031:Epstein-Barr Virus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology*; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics; D005260:Female; D004854:Herpesvirus 4, Human / Q000145:classification* / Q000235:genetics; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology*; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D018570:Risk Assessment; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D014764:Viral Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: D004279:DNA, Viral; C402641:EBNA-2 protein, Human herpesvirus 4; D019309:Epstein-Barr Virus Nuclear Antigens; D014764:Viral Proteins