Influenza has been in the news a lot this winter, whether it involves poultry, people or pigs. It certainly seems the more you learn, the less you know about the related viruses. The influenza virus is an example of survival at its best, as viruses adapt as needed to survive.

Swine influenza viruses were first isolated in the United States in 1930. Since then, SIV   has become an economically important herd-health issue for pork producers. Most notably, SIV is a dominant component of the porcine respiratory disease complex.

It’s hard to keep pace with developments, but the National Pork Board and the American Association of Swine Veterinarians have created a fact sheet on influenza viruses called “Influenza: Pigs, People and Public Health.” Christopher Olsen, DVM, University of Wisconsin, wrote the fact sheet, which was then reviewed by a panel of influenza experts.

The document explains such things as how and why virus subtypes exist; how reassortment occurs; and a list of recommendations to reduce the transmission of the influenza virus.

You may access the fact sheet by going to NPB’s Science and Technology Web site, at From there, go to “Library” then to “Producer/Public Health.” That will take you to “Publications” and on to “Fact Sheets.”