Hemorrhagic viral keratoconjunctivitis in Taiwan caused by adenovirus types 19 and 37 - Applicability of polymerase chain reaction-restriction fragment length polymorphism in detecting adenovirus genotypes

Purpose. Acute keratoconjunctivitis with prominent subconjunctival hemorrha ge (SCH) is usually perceived by a clinician as acute hemorrhagic conjuncti vitis (AHC) associated with enteroviruses; however, SCH can also be an aden oviruses infection. A rapid and sensitive laboratory diagnosis is helpful f or differential diagnosis. Therefore, the sensitivity and applicability of polymerase chain reaction (PCR) and reverse transcription (RT)-PCR diagnose s were evaluated for keratoconjunctivitis associated with viral infection. Methods. Conjunctival swabs from patients with acute conjunctivitis were te sted using a PCR-restriction fragment length polymorphism (PCR-RFLP) for ad enovirus detection and RT-PCR for enterovirus detection. The results were c ompared with those using the culture isolation and neutralization test; als o, the clinical findings of the patients were analyzed with special attenti on to SCH patterns. Results. Neither coxsackievirus A type 24 variant (CA24 v) nor enterovirus type 70 (EV70) was detected in 113 patients with acute c onjunctivitis, The positive results of adenovirus (Ad) were 39.9% by the PC R method and 37.1% by culture isolation. For the patients with adenoviral c onjunctivitis, 68.1% was owing to Ad37 and 19.2% was owing to Ad19. SCH was present in 51.5% of the positive cases, and 44.7% of the Ad-positive patie nts had secondary illnesses. Conclusions. SCH can be a predominant presenta tion of Ad19 and Ad37 keratoconjunctivitis and may herald a new stage in th e evolution of adenoviruses. PCR and PCR-RFLP are rapid and reliable method s for Ad detection and typing; however, if the amplified genes and restrict ion enzymes are not properly selected, they may not be able to detect new g enotypes of adenoviruses or the evolution of these viruses.