title: Molecular epidemiology of adenoviral keratoconjunctivitis in Saudi Arabia.
abstract: OBJECTIVE
  Adenoviral keratoconjunctivitis is a major cause of ocular morbidity and may lead to visual loss. Adenovirus types 8, 19, and 37 may cause epidemic keratoconjunctivitis. The main objective of this study was to determine the types of adenoviruses causing keratoconjunctivitis in Saudi Arabia.
  
  
  METHODS
  We conducted a non-interventional observational clinical study. Seventy three eyes from 65 patients who presented to The Eye Center in Riyadh, Saudi Arabia with clinical features of acute adenoviral keratoconjunctivitis were included. Each patient underwent complete clinical examination and features such as membranous reaction, conjunctival hemorrhage, subepithelial corneal infiltrates, and preauricular lymph node enlargement were recorded. Conjunctival swabs were obtained from patients with presumed acute viral conjunctivitis. Immunochromatography (IC) and restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) were performed on the conjunctival swabs obtained from each eye. Serotype identification was performed using direct sequencing technique.
  
  
  RESULTS
  Forty-nine (67.1%) were adenovirus type 8, 8 (11.0%) were adenovirus type 3, 6 (8.2%) type 37, 5 (6.8%) were adenovirus type 4, and 2 (2.3%) type 19. The remaining 5 were types 14, 19, and 22. The prevalence of membranous conjunctivitis was highest (83%) among eyes with adenovirus type 37 while subepithelial corneal opacities were most commonly seen among eyes with adenovirus type 8 (47%). Immunochromatography tests were positive for adenovirus in 48 (65.7%) out of 73 eyes.
  
  
  CONCLUSIONS
  This study determined the types of adenoviruses causing keratoconjunctivitis at one center in Saudi Arabia. Direct sequencing techniques is an efficient, accurate, and rapid means of diagnosing adenoviral keratoconjunctivitis. The most common causes of adenoviral keratoconjunctivitis in Saudi Arabia were adenovirus types 8, 3, and 37. Membranous conjunctivitis and subepithelial opacities had the highest frequency of adenovirus types 37 and 8, respectively. Lymph nodes enlargement was least likely in adenovirus type 4.
authors.affiliation: The Eye Center and The Eye Foundation for Research in Ophthalmology, Riyadh, Saudi Arabia. k.tabbara@nesma.net.sa
authors.forename: Khalid F
authors.initials: KF
authors.lastname: Tabbara
authors.forename: Nazri
authors.initials: N
authors.lastname: Omar
authors.forename: Ehab
authors.initials: E
authors.lastname: Hammouda
authors.forename: Masataka
authors.initials: M
authors.lastname: Akanuma
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohguchi
authors.forename: Toshihide
authors.initials: T
authors.lastname: Ariga
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Tagawa
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Kitaichi
authors.forename: Susumu
authors.initials: S
authors.lastname: Ishida
authors.forename: Koki
authors.initials: K
authors.lastname: Aoki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ishiko
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Ohno
mesh_terms: D000256:Adenoviridae / Q000145:classification; D000257:Adenoviridae Infections / Q000453:epidemiology* / Q000235:genetics* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000375:Aging / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002845:Chromatography; D003236:Conjunctivitis, Viral / Q000453:epidemiology* / Q000235:genetics* / Q000473:pathology / Q000821:virology; D005260:Female; D006801:Humans; D007637:Keratoconjunctivitis / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology / Q000821:virology*; D008297:Male; D008875:Middle Aged; D012529:Saudi Arabia / Q000453:epidemiology; D012703:Serotyping; D012727:Sex Characteristics; D055815:Young Adult