title: The epidemiology of infectious mononucleosis in Northern Scotland: a decreasing incidence and winter peak.
abstract: BACKGROUND
  Infection with Epstein-Barr virus (EBV) is almost ubiquitous in humans and generally occurs at two ages: infantile, which is usually asymptomatic and associated with poorer socioeconomic conditions, and adolescent, which causes infectious mononucleosis (IM) in ~25% cases. The determinants of whether the infection causes IM remain uncertain. We aimed to evaluate seasonality and temporal trends in IM.
  
  
  METHODS
  Data from all Monospot tests, used as a marker for IM, were collected from the Grampian population over 16 years.
  
  
  RESULTS
  Positive Monospot test results peaked at 17 years in females and 19 in males. Females had 16% more diagnoses, although 55% more tests. IM was ~38% more common in winter than summer. The annual rate of positive tests decreased progressively over the study period, from 174/100 000 (95% CI 171-178) in 1997 to 67/100 000 (95% CI 65-69) in 2012.
  
  
  CONCLUSIONS
  IM appears to be decreasing in incidence, which may be caused by changing environmental influences on immune systems. One such factor may be exposure to sunlight.Words 168.
  
  
  BACKGROUND
  The Medical Research Council and NHS Grampian-MS endowments.
authors.affiliation: Division of Applied Health Sciences, College of Life Sciences and Medicine, University of Aberdeen, Room 1:015, Polwarth Building, Foresterhill, Aberdeen AB252ZD, UK. e.visser@abdn.ac.uk.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Visser
authors.forename: Denis
authors.initials: D
authors.lastname: Milne
authors.forename: Ian
authors.initials: I
authors.lastname: Collacott
authors.forename: David
authors.initials: D
authors.lastname: McLernon
authors.forename: Carl
authors.initials: C
authors.lastname: Counsell
authors.forename: Mark
authors.initials: M
authors.lastname: Vickers
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D007223:Infant; D007244:Infectious Mononucleosis / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D007841:Latex Fixation Tests; D008297:Male; D008875:Middle Aged; D012606:Scotland / Q000453:epidemiology; D012621:Seasons; D055815:Young Adult