Molecular epidemiology study of swine influenza virus revealing a reassorted virus H1N1 in swine farms in Cuba

- We describe the emergence of a novel H1N1 swine influenza virus in pigs.
- The virus was originated from a reassortment event between the H1N1 pandemic influenza virus and classical swine influenza virus.
- The gene constellation of the isolate is novel and unique.
- The establishment of H1N1 pandemic influenza virus in swine is suggested to occur.

In this report, we describe the emergence of reassorted H1N1 swine influenza virus, originated from a reassortment event between the H1N1 pandemic influenza virus (H1N1p/2009) and endemic swine influenza virus in Cuban swine population. In November 2010, a clinical respiratory outbreak was reported on a pig fattening farm in Cuba. Phylogenetic analysis showed that all the genes of one of the isolate obtained, with the exception of neuraminidase, belonged to the H1N1p/2009 cluster. This finding suggests that H1N1pdm has been established in swine and has become a reservoir of reassortment that may produce new viruses with both animal and public health risks.