Performance Characteristics of FilmArray Respiratory Panel v1.7 for Detection of Adenovirus in a Large Cohort of Pediatric Nasopharyngeal Samples: One Test May Not Fit All

The FilmArray Respiratory Panel (RP) v1.7 assay has improved sensitivity for detection of human adenovirus (HAdV), compared to an earlier version (RP v1.6). RP v1.7 was designed for detection of species B, C, and E but may show variable detection of species A, D, and F. We sought to evaluate the clinical and analytical performance of RP v1.7 for detection of HAdV in a large pediatric cohort. Respiratory specimens obtained from a tertiary care children's hospital between February 2014 and February 2015 were tested for HAdV by RP v1.7. If the RP v1.7 results were negative for HAdV, then the specimens were reflexed to a HAdV-specific laboratory-developed PCR (LD-PCR) assay for confirmation. A subset of specimens underwent secondary confirmatory testing using another commercially available HAdV PCR assay and a molecular typing assay for species identification. Among 4,750 specimens, a total of 146 specimens (3.1%) were HAdV positive by RP v1.7. HAdV was detected by LD-PCR in an additional 220 specimens that were negative by RP v1.7. Overall, a nearly 5% increase in HAdV detection was observed when RP v1.7-negative specimens were reflexed to LD-PCR testing. RP v1.7 did not detect HAdV with either low viral burden (threshold cycle values of >30) or nonrespiratory species (species A, D, and F), as shown in both clinical and analytic data. While the level of sensitivity of RP v1.7 may be adequate for testing among otherwise healthy children, the decreased sensitivity may be problematic for immunocompromised patients, in whom low levels of HAdV in the respiratory tract may precede systemic infection and require early intervention.