Retrospectively testing samples collected in a prospective observational cohort study of patients at risk of developing ARDS, CMV reactivation (ie. CMV DNA by PCR) was detected in BALF and/or plasma of 2/5 [40%] of subjects who developed ARDS, in sequential samples from 7/20 [35%] patients with ARDS, but not in patients at risk but who did not develop ARDS (0/5) [Limaye 2009 unpublished data]. In a separate study, CMV reactivation was retrospectively assessed by PCR in BALF of 88 subjects enrolled in a randomized trial of fish oil for treatment of ALI. Seropositivity at baseline (ie. evidence of latent CMV infection) in the cohort was 65% (similar to prior age-related estimates), and CMV reactivation (ie. CMV DNA by PCR) was detected in BALF of 12/57 [21%] patients [Limaye unpublished data 2009].