title: Correlates of illness severity in infectious mononucleosis.
abstract: BACKGROUND
  Understanding the spectrum and frequencies of Epstein-Barr virus (EBV) complications and markers of illness severity in immunocompetent patients with primary EBV infection will inform management of patients with EBV-related illnesses.
  
  
  OBJECTIVE
  To determine the clinical and laboratory correlates of illness severity among infants, children and youth with infectious mononucleosis (IM).
  
  
  METHODS
  Study subjects with confirmed IM were prospectively enrolled. Illness severity was assessed at baseline and at six weeks using a scoring tool. Peripheral blood viral loads served as a measure of viral burden.
  
  
  RESULTS
  Among 32 children and young adults with IM, the median age was 16 years (range two to 24 years). The predominant clinical findings were lymphadenopathy (23 of 32 [72%]), pharyngitis (16 of 32 [50%]), fever (nine of 32 [28%]) and splenomegaly (six of 32 [19%]). With respect to symptoms or signs that persisted to at least six weeks after illness onset, the predominant complaint was lymphadenopathy in 35% of subjects available for reassessment. Deranged liver function tests were present at presentation in up to 44% of subjects. Patients with the highest viral loads at presentation had significantly higher illness severity scores associated with fatigue (P=0.02). Other than the scores associated with fatigue, viral load values were not significantly correlated with the illness severity scores at baseline and at six weeks.
  
  
  CONCLUSIONS
  In IM, viral loads are not necessarily correlated with illness severity, with the exception of fatigue. EBV-related hepatitis is common in IM, confirming the status of this virus as a relatively common cause of transient hepatitis in children and youth. This entity is not necessarily a marker of disease severity.
authors.affiliation: Division of Infectious Diseases, Hospital for Sick Children, Toronto, Ontario;
authors.forename: John
authors.initials: J
authors.lastname: Odame
authors.affiliation: Division of Infectious Diseases, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta;
authors.forename: Joan
authors.initials: J
authors.lastname: Robinson
authors.affiliation: Division of Infectious Diseases, Hospital for Sick Children, Toronto, Ontario;
authors.forename: Nasser
authors.initials: N
authors.lastname: Khodai-Booran
authors.affiliation: Division of Infectious Diseases, Hospital for Sick Children, Toronto, Ontario;
authors.forename: Simon
authors.initials: S
authors.lastname: Yeung
authors.affiliation: Mount Sinai Hospital, University of Toronto;
authors.forename: Tony
authors.initials: T
authors.lastname: Mazzulli
authors.affiliation: The Research Institute, Hospital for Sick Children, Toronto, Ontario.
authors.forename: Derek
authors.initials: D
authors.lastname: Stephens
authors.affiliation: Division of Infectious Diseases, Hospital for Sick Children, Toronto, Ontario; ; The Research Institute, Hospital for Sick Children, Toronto, Ontario.
authors.forename: Upton D
authors.initials: UD
authors.lastname: Allen
keywords: Epstein-Barr virus; Hepatitis; Mononucleosis; Viral load