Detection of Equine-2 Influenza Virus by the Real-Time PCR

We developed the TaqMan based real-time EZ RT-PCR assay for the detection of equine-2 influenza viruses (H3N8). Specificity was tested for various wild strains of equine influenza viruses. Our TaqMan EZ RT-PCR could detect all recent European and American strains isolated after 1989, and historical strains except a variant A/equine/Tokyo/71 strain isolated in 1971. Sensitivity was evaluated to detect 10 EID50 viral RNA using the RNA extracted from hen’s egg allantoic fluid infected with A/equine/La Plata/93 (LP93) strain. Detection sensitivity of TaqMan EZ RT-PCR method from the 180 nasal swab samples collected from horses experimentally infected with LP93 strain was compared with the RT-PCR and egg isolation methods. The results suggested that the TaqMan EZ RT-PCR would be the more sensitive method to detect the equine-2 influenza virus than the egg isolation method and as sensitive as RT-PCR method.