title: Undiagnosed respiratory viruses in children.
abstract: OBJECTIVE
  An estimated 12 to 32 million upper respiratory infections occur in young children each year. In addition, 20% to 53% of infants will have > or = 1 episode of lower respiratory infection in the first year of life. The current methods of diagnosing respiratory viruses are limited in scope and sensitivity. Polymerase chain reaction is a more sensitive method than antigen detection and is often used for newly discovered viruses. Using polymerase chain reaction, we sought to diagnose adenoviruses, human bocavirus, and human metapneumovirus at our children's hospital.
  
  
  METHODS
  Nasal-swab specimens submitted for antigen detection of respiratory viruses were collected and processed by using polymerase chain reaction to detect adenoviruses, human bocavirus, and human metapneumovirus. Inpatient and emergency department records were reviewed for clinical and demographic data.
  
  
  RESULTS
  Approximately 1500 specimens were collected over 21 months; they contained adenoviruses, human bocavirus, and human metapneumovirus in 5.9%, 5.6%, and 5.2% of children, respectively. Using polymerase chain reaction and antigen detection, a viral agent was identified in as many as 62% of the specimens. Lower respiratory tract disease was present most frequently in patients infected with human metapneumovirus (63%) and least frequently in those infected with adenoviruses (45%). We detected adenoviruses by polymerase chain reaction in 59 patients for whom the antigen-detection test results were negative. A paroxysmal cough led to clinical suspicion of Bordetella pertussis infection in 19% of patients infected with human bocavirus.
  
  
  CONCLUSIONS
  Adenoviruses, human bocavirus, and human metapneumovirus were each present in approximately 5% of specimens submitted for respiratory virus rapid testing. The lower respiratory tract was more commonly affected in patients with human bocavirus and human metapneumovirus infections. Adenovirus was often undiagnosed by antigen detection. Other findings included the presence of a pertussis-like illness associated with human bocavirus.
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, Center for AIDS Research, University of California, San Diego, California, USA. john.arnold@med.navy.mil
authors.forename: John C
authors.initials: JC
authors.lastname: Arnold
authors.forename: Kumud K
authors.initials: KK
authors.lastname: Singh
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Spector
authors.forename: Mark H
authors.initials: MH
authors.lastname: Sawyer
mesh_terms: D000256:Adenoviridae / Q000302:isolation & purification*; D052660:Bocavirus / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006801:Humans; D015994:Incidence; D029121:Metapneumovirus / Q000302:isolation & purification*; D009297:Nasal Mucosa / Q000821:virology; D016133:Polymerase Chain Reaction; D011336:Probability; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology*; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity
chemical_list: D004279:DNA, Viral