title: Diagnosis of Pediatric Acute Adenovirus Infections: Is a Positive PCR Sufficient?
abstract: 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.
authors.affiliation: 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.
authors.forename: Eunkyung
authors.initials: E
authors.lastname: Song
authors.forename: Huanyu
authors.initials: H
authors.lastname: Wang
authors.forename: Adriana E
authors.initials: AE
authors.lastname: Kajon
authors.forename: Doug
authors.initials: D
authors.lastname: Salamon
authors.forename: Siwen
authors.initials: S
authors.lastname: Dong
authors.forename: Octavio
authors.initials: O
authors.lastname: Ramilo
authors.forename: Amy
authors.initials: A
authors.lastname: Leber
authors.forename: Preeti
authors.initials: P
authors.lastname: Jaggi
mesh_terms: D000208:Acute Disease; D000256:Adenoviridae / Q000145:classification / Q000235:genetics*; D000258:Adenovirus Infections, Human / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009305:Nasopharynx / Q000821:virology; D016133:Polymerase Chain Reaction / Q000379:methods*; D012189:Retrospective Studies; D014773:Virology / Q000379:methods* / Q000592:standards*