Genetic and pathogenic characterization of thai swine influenza viruses after the introduction of pandemic H1N1 2009

Abstract

Since pandemic H1N1 (pH1N1) 2009 influenza virus emerged in April 2009, at least 18,449 people died and was called Swine-origin 2009 A (H1N1) or “swine flu” due to its genetic character. Swine influenza virus (SIV) surveillance was conducted from June 2010 to May 2012 in Thailand. The results of the surveillance revealed that pH1N1 was the most prevalence in 2010. Later, reassortant H1N1, H3N2 and H1N2 viruses were also isolated. As a result of the discovery of the emergent SIV, pathogenesis studies of this novel virus was conducted in order to plan for future disease protection and control measures both in swine and human populations. Hence, pathogenesis studies in pigs and commingling sentinel ducks were conducted. The pH1N1 and its reassortant virus (rH1N1) isolated from pigs in Thailand were inoculated into 2 separate cohorts. A day later, sentinel ducks were commingled with pH1N1 or rH1N1 inoculated pigs in separate groups. This present studies suggested that both pH1N1 and rH1N1 viruses were able to infect and replicate in pigs and sentinel ducks. Moreover, those viruses were capable to transmit from infected pigs to sentinel ducks when animals were commingling but viral replication in ducks was limited. From the study, virological and serological surveillance of swine influenza are of importance for the prevention and control of swine influenza and for preparedness of future pandemic influenza in humans.