Pandemic influenza in the age of mammals
Speaker: Martha Nelson, PhD
Fogarty International Center, NIH
Abstract: The ecology of influenza A viruses (IAVs) in non-human mammalian hosts underwent dramatic changes at the end of the 20th century and the beginning of the 21st century, introducing important new pandemic threats. As a result, the H1N1 virus that caused the 2009 influenza pandemic came not from birds, but from pigs. Beginning in the 1990s, the genetic diversity of IAVs in US swine increased dramatically and spread across the globe, following the direction of the international trade of live swine. In this talk, I’ll describe how the evolution and spatial spread of diverse IAV lineages in swine facilitated the emergence of the 2009 H1N1 pandemic virus, and how viral genetic diversity continues to expand in swine globally, producing viruses that could cause the next pandemic. In fact, newly emerged viruses circulate in US exhibition swine and have infected > 400 children attending agricultural fairs during summer months. I’ll also discuss new, unpublished findings describing how the genetic diversity of IAV is rapidly expanding in canines in Asia, creating additional pandemic threats. The emergence of new viruses in Asian canines is particularly alarming, as these hosts are raised for consumption and exposed to high viral diversity in live animal markets, and kept as pets with very high human contact in households. Going forward, understanding pandemic risk requires a more complete knowledge of the viral diversity circulating in under-studied mammalian hosts globally, and an understanding of how changes in animal movements and population structures drive the evolution of these new viruses.