Comparison of a commercial qualitative real-time RT-PCR kit with direct immunofluorescence assay (DFA) and cell culture for detection of influenza A and B in children

J Clin Virol. 2008 Jun;42(2):190-3. doi: 10.1016/j.jcv.2008.01.013. Epub 2008 Apr 18.


Background: Institutional pandemic planning prompted a study of the molecular detection of influenza virus from respiratory specimens in children, compared to conventional diagnostics.

Objective: To evaluate the performance of a commercial qualitative real-time RT-PCR kit (rRT-PCR), the artus Influenza LC RT-PCR (Qiagen). STUDY DESIGN (METHODS): Specimens were pre-selected to include a high percentage of positives by direct immunofluorescence assay (DFA) or culture. The sensitivity and specificity of the kit for detection of influenza A and B in children were determined against the gold standard, DFA and culture. Specimens yielding discordant results between artus and the gold standard were tested against a reference rRT-PCR assay (Centers for Disease Control) to create an "expanded gold standard".

Results: When compared to DFA or cell culture, the sensitivity of the rRT-PCR artus kit was 96.2% and the specificity was 94%. It detected influenza RNA in 6.0% of clinical samples negative by DFA or culture. Using the expanded gold standard, the revised sensitivity was 98.7% (98.6% for influenza A and 97.6% for influenza B) and the specificity was 100%.

Conclusion: The artus Influenza LC RT-PCR kit is an effective alternative to virus isolation and DFA for the detection of influenza A and B in pediatric clinical specimens.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Fluorescent Antibody Technique, Direct
  • Humans
  • Infant
  • Infant, Newborn
  • Influenza A virus / genetics
  • Influenza A virus / immunology
  • Influenza A virus / isolation & purification*
  • Influenza B virus / genetics
  • Influenza B virus / immunology
  • Influenza B virus / isolation & purification*
  • Influenza, Human / diagnosis*
  • Influenza, Human / virology
  • Nose / virology
  • RNA, Viral / analysis
  • Reagent Kits, Diagnostic*
  • Reverse Transcriptase Polymerase Chain Reaction / methods*
  • Sensitivity and Specificity
  • Specimen Handling / methods
  • Virus Cultivation


  • RNA, Viral
  • Reagent Kits, Diagnostic