Comparison of nasopharyngeal flocked swabs and nasopharyngeal wash collection methods for respiratory virus detection in hospitalized children using real-time polymerase chain reaction

J Virol Methods. 2012 Oct;185(1):89-93. doi: 10.1016/j.jviromet.2012.06.009. Epub 2012 Jun 21.


This paper describes the molecular detection of respiratory viruses from nasopharyngeal flocked swabs (flocked swabs) and nasopharyngeal washes (washes) in a clinical setting. Washes and flocked swabs collected from children<3 years old hospitalized with a lower respiratory tract infection were tested for parainfluenza virus 1-3, respiratory syncytial virus, influenza A and B and metapneumovirus (Group 1) and adenovirus, rhinovirus and coronavirus (Group 2) using real-time reverse transcriptase PCR (rRT-PCR). A consensuses standard was used to determine sensitivity and compare cycle thresholds (C(T)) of washes and flocked swabs for each virus and group of viruses. Sensitivities ranged from 79 to 89% and 69 to 94% for flocked swabs and washes, respectively, excluding AdV which had a sensitivity of 35% for flocked swabs. When the flocked swabs and washes of Group 1 viruses were collected on the day of admission, the sensitivity of both sample types was 100%. Wash specimens had a lower C(T) value and higher sensitivity than flocked swabs; however there was no statistical difference in the sensitivity of a flocked swab (89%) versus wash (93%) for the detection of Group 1 viruses, particularly when samples were collected on the same day. Flocked swabs may be a useful alternative to washes for detection of respiratory viruses in clinical settings.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Child, Hospitalized
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Molecular Diagnostic Techniques / methods*
  • Nasopharynx / virology*
  • Real-Time Polymerase Chain Reaction / methods*
  • Respiratory Tract Infections / diagnosis*
  • Respiratory Tract Infections / virology*
  • Sensitivity and Specificity
  • Specimen Handling / methods*
  • Virology / methods*