Molecular evaluation of influenza A virus in swine at slaughterhouses in Colombia

Objective. To assess the presence of influenza A virus and to evaluate the impact of the 2009 pandemic H1N1 influenza virus on the endemic strains circulating in the Colombian swine population after its emergence and spread. Materials and methods. 369 lung tissue samples were collected from clinically normal slaughterhouse pigs from 11 geographic regions of Colombia, which were analyzed using qRT-PCR test for the detection of influenza A virus. After molecular detection, positive samples were processed to perform isolation trials in specific pathogen free chicken embryo eggs, and the presence of the virus was accomplished by hemagglutination test and RT-PCR assays. Results. Molecular detection techniques showed circulation of swine influenza viruses in five out of 11 geographic regions monitored. Likewise, sample testing by viral isolation analysis enabled successful recovery and confirmation of five viral strains from two geographic regions. Conclusions. It was possible to demonstrate that slaughterhouses represent a feasible alternative for research and characterization of influenza virus, allowing researchers to collect pig samples from different origins. They also provide a useful tool for achieving viral isolation and early detection of molecular changes that would help to anticipate the appearance of strains with pandemic and/or epidemic potential throughout the national territory.