An ocular model of adenovirus type 5 infection in the NZ rabbit.

Ocular adenoviral infections occur worldwide, and currently, there is no ocular animal model for evaluating new antivirals or studying pathogenesis. With a paired-eye design, an ocular model was developed in 32 New Zealand rabbits following topical and intrastromal inoculation with a clinical isolate of adenovirus type 5 (Ad5 McEwen). Clinical signs of infection--conjunctivitis, corneal edema, subepithelial infiltrates, and iritis--and seroconversion were evaluated. Replicating virus on the ocular surface was determined by serial ocular titers. Reproducible acute ocular infection was demonstrated in 32 of 32 infected eyes (100%), with mean viral replication lasting for 8.3 days. Peak ocular viral titers (10(3) plaque forming units/ml) were achieved on day three after inoculation and represented a 2 log increase (100 times) over day one. Ocular viral replication was associated with acute conjunctivitis (24/34 eyes, 75%), and delayed-onset presumed immune-mediated clinical disease was associated with: blepharoconjunctivitis (21/32 eyes, 66%), iritis (29/32 eyes, 91%), corneal edema (32/32 eyes, 100%), and subepithelial corneal infiltrates (30/32 eyes, 94%). Seroconversion was demonstrated in 26 of 31 rabbits (84%). The study concludes that a potentially useful animal model of adenoviral ocular infection can be attained.