title: WHO external quality assessment project for the detection of subtype influenza A viruses by polymerase chain reaction--summary analysis, 2007 and 2008.
mesh_terms: D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification; D009980:Influenza A virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis / Q000821:virology*; D007753:Laboratories / Q000592:standards; D016133:Polymerase Chain Reaction / Q000592:standards; D011786:Quality Control; D014944:World Health Organization