Human adenovirus (HAdV), especially species C (HAdV-C), can be detected incidentally by polymerase chain reaction in nasopharyngeal (NP) samples, making it difficult to interpret clinical significance of a positive result. We classified patients into groups based on HAdV culture positivity from respiratory specimens and the presence of an identified co-pathogen. We hypothesized that HAdV-C would be over-represented and viral burden would be lower in patients most likely to have incidental detection (ie, with a negative viral culture and documented co-pathogen).
Immunocompetent children with HAdV + nasopharyngeal specimens were classified into 4 groups: group I (HAdV culture (+) and no co-infection), group II (culture (+) and co-infection), group III (culture (−) and no co-infection) and group IV (culture (−) and co-infection). Viral burden (cycle threshold) and species were compared among groups.
Of 483 nasopharyngeal specimens, HAdV was isolated in culture in 252 (52%); co-infection was found in 265 (55%) patients. Group I (most consistent with acute disease) had significantly lower cycle thresholds (median 23.9; interquarile range 22.2–28.1) compared with group IV (most consistent with incidental detection; median 37.3; interquarile range 35.3–38.9; P < 0.0001). HAdV-C accounted for 41% samples of group I and 83% of group IV (P < 0.0001). We identified a subset of 22 patients with bacterial or fungal co-pathogens, 18 of whom had no growth on viral culture (group IV) with a median cycle threshold of 37.4 (interquarile range 33.9–39.2).
Species identification and viral burden may assist in interpretation of a positive HAdV result. Low viral burden with HAdV-C may be consistent with incidental detection.
Supplemental Digital Content is available in the text.
From the *Division of Pediatric Infectious Diseases and †Department of Pathology and Laboratory Medicine, Nationwide Children’s Hospital, Columbus, Ohio; ‡Infectious Disease Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico; and §The Ohio State University, Columbus, Ohio.
Accepted for publication August 11, 2015.
The authors have no funding or conflicts of interest to disclose.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.pidj.com).
Address for correspondence Preeti Jaggi, MD, Nationwide Children’s Hospital, 700 Children’s Drive, Columbus, OH 43205. E-mail: Preeti.email@example.com