title: Pediatric orbital cellulitis in the Haemophilus influenzae vaccine era.
abstract: OBJECTIVE
  To evaluate the microbiology of pediatric orbital cellulitis in blood cultures and abscess drainage cultures following the introduction of the Haemophilus influenzae serotype b (Hib) vaccine.
  
  
  METHODS
  The medical records of all pediatrics patients (aged <18 years) at a tertiary pediatric hospital during the period January 2000 to July 2011 with a computed tomography orbital imaging querying "orbital cellulitis," "periorbital cellulitis," "preseptal cellulitis," or "post-septal cellulitis" were retrospectively reviewed. The records, microbiology, and radiology of these patients were reviewed to assess the rates and complications of H. influenzae orbital cellulitis, including bacteremia and meningitis.
  
  
  RESULTS
  A total of 149 patients were diagnosed with preseptal or orbital cellulitis, of whom 101 (mean age, 7.2 ± 4.0) had true orbital cellulitis. No patients grew H. influenzae from blood cultures. Of the 101 patients, 30 (29.7%) required surgical drainage and had abscess drainage fluid sent for microbiology. Of these, 18 (64.3%) had a positive culture: 4 (13.3%) grew H. influenzae from their abscess drainage fluid samples; 1 grew H. influenzae alone; and 3 had mixed growth that included H. influenzae. The patients positive for H. influenzae were significantly older and had significantly larger abscesses.
  
  
  CONCLUSIONS
  Although there were no cases of H. influenzae bacteremia or meningitis in our cases of orbital cellulitis, abscess drainage fluid microbiology indicated that H. influenzae remains a cause of orbital cellulitis. H. influenzae abscess volume was significantly larger than other bacterial abscesses and was associated with abscesses of mixed bacterial growth in older children.
authors.affiliation: Department of Ophthalmology, The Hospital for Sick Children, Toronto, Ontario, Canada. Electronic address: Abhishek.sharma@sickkids.ca.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Department of Ophthalmology, University of Toronto, Toronto, Ontario, Canada; Department of Ophthalmology, Mount Sinai Hospital, Toronto, and Southlake Regional Health Centre, Newmarket, Ontario, Canada.
authors.forename: Eugene S
authors.initials: ES
authors.lastname: Liu
authors.affiliation: Uptown Eye Specialists, Concord, Ontario, Canada.
authors.forename: Tran D
authors.initials: TD
authors.lastname: Le
authors.affiliation: Division of Ophthalmology, University of Calgary, Calgary, Alberta, Canada; Mitchell Eye Center, Calgary, Alberta, Canada.
authors.forename: Feisal A
authors.initials: FA
authors.lastname: Adatia
authors.affiliation: Department of Ophthalmology, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Ophthalmology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: J Raymond
authors.initials: JR
authors.lastname: Buncic
authors.affiliation: Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Blaser
authors.affiliation: Microbiology Department, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Richardson
mesh_terms: D000038:Abscess / Q000175:diagnosis / Q000382:microbiology* / Q000601:surgery; D016470:Bacteremia / Q000175:diagnosis / Q000382:microbiology* / Q000601:surgery; D001419:Bacteria / Q000302:isolation & purification; D016667:Bacterial Capsules; D002648:Child; D002675:Child, Preschool; D004322:Drainage; D015818:Eye Infections, Bacterial / Q000175:diagnosis / Q000382:microbiology* / Q000601:surgery; D005260:Female; D006192:Haemophilus Infections / Q000175:diagnosis / Q000382:microbiology* / Q000601:surgery; D018073:Haemophilus Vaccines / Q000008:administration & dosage*; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008583:Meningitis, Haemophilus / Q000175:diagnosis / Q000382:microbiology / Q000601:surgery; D054517:Orbital Cellulitis / Q000175:diagnosis / Q000382:microbiology* / Q000601:surgery; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014611:Vaccination
chemical_list: D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine