Human rapid influenza diagnostic test: efficacy and significance for using in animal

Rapid influenza diagnostic tests (RIDTs) could considerably assist in clinical management resolving outbreaks of diseases in humans and animals. The RIDT for animals is rarely available and considerably expensive, especially in Thailand. In this study, therefore, the objective of this study was to determine the capacity of a commercial human RIDT “QuickNavi™Flu2”, an RIDT for influenza viruses A and B, to detect influenza viruses A antigen including 2 inactivated swine influenza viruses: H1N1 and H3N2, canine parainfluenza virus, and feline calicivirus. In addition, the efficacy of QuickNavi™Flu2 was compared with the real-time polymerase chain reaction assay (real-time rt-PCR). Both of SIV were used as stock solutions, and were serially diluted 6 concentrations before testing. The stock and diluted solutions of both SIV, specimens of canine parainfluenza virus, feline calicivirus and 96 unknown samples were tested by QuickNavi™Flu2 according to the guideline. Then all of samples were repeated testing with real-time rt-PCR assay. Results showed that Quick Navi-Flu could not give positive results for dilutions lower than 1:10 and 1:100, respectively. The sensitivity and specificity values of QuickNavi™Flu2 test in comparison to real-time rt-PCR assay for influenza A virus were 36.1% and 100%, respectively. In conclusion, a human RIDT can detect swine influenza H1N1 and H3N2 in high viral concentration, and appeared to be a useful tool for screening in animals when the viral load is sufficient.