This large multinational retrospective analysis examined host and pathogen factors that were predictive of keratoconjunctivitis outcomes.

Study design

Using data from a randomized controlled trial, the study included 500 participants from United States, India, Brazil, and Sri Lanka. Each had a clinical diagnosis of keratoconjunctivitis and had a positive rapid test results for adenovirus (AdenoPlus; Quidel).

Outcomes

Approximately 390 participants (78%) showed evidence of adenovirus by PCR.

Among adenovirus-positive participants, a total of 4 species and 21 different types of adenovirus were detected. Adenovirus D species was most common, occurring in 63% of cases, and was associated with more severe signs and symptoms, a higher rate of subepithelial infiltrate development, and a slower decline in viral load compared with all other adenovirus species.

The clinical courses of all patients with non-adenovirus D species infection and adenovirus-negative keratoconjunctivitis were similar. Sign resolution appeared to be influenced significantly by viral species and country of origin, whereas symptom resolution was associated significantly with age and country.

Limitations

The inclusion criteria of adenovirus positivity limited the study cohort. Because the clinical course of adenovirus-negative participants was not studied, the study is not generalizable to all patients with keratoconjunctivitis.

Clinical significance

This study found an unexpectedly diverse range of adenoviral species associated with keratoconjunctivitis, particularly in the United States compared with other parts of the world. Surprisingly, a substantial proportion of keratoconjunctivitis cases did not have detectable adenovirus on PCR. Outcomes differed significantly based on adenoviral species; participants infected with adenovirus D exhibited slow resolution of signs, symptoms, and viral load.