Submitted to: Pig Veterinary Society International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/3/2002
Publication Date: 6/3/2002
Technical Abstract: Swine influenza (SI) is an acute respiratory disease of swine caused by type A influenza viruses. Before 1998, mainly "classical" H1N1 SI viruses (SIV) were isolated from swine in the U.S. Since then, antigenetically distinct reassortant H3- and H1-SIVs have been identified as causative agents of respiratory disease in pigs on U.S. farms. Improvement in SIV diagnostics is needed in the light of the recently observed rapid evolutio of H1 and H3 swine influenza viruses and their potential threat to human health. To address this need, a real-time (R.A.P.I.D. System) RT-PCR assay for H1- and H3-SIVs was developed and evaluated in experimentally infected pigs. We established a M-gene based RT-PCR assay which is able to detect H1- and H3-subtypes of SIVs with a sensitivity of approximately 5 RNA copies of in vitro generated M-specific negative-sense RNA molecules and approximately 2 TCID50 in nasal swabs of experimentally SIV-infected pigs. This RT-PCR assay can be performed in less than 2 hours. In addition, we have designed and tested H3- and N1-specific primer and probe sets in order to differentiate between different SIVs subtypes. The H3 and N1-primer sets are (i) specific for their respective viral gene, (ii) able to distinguish between various SIV-subtypes and, therefore, (iii) can be used in multiplex PCR assays. This real-time RT-PCR assay allows rapid on-site SIV detection and will have application for SIV surveillance and management of disease outbreaks.