If pigs catch bird flu, we could be in for a real nightmare

Flu likes to bind to a sugar on the surface of cells, and the reason bird flu doesn’t usually spread among people is because our sugars are very different, explains Richard Webby, a flu specialist at St. Jude’s Children’s Research Hospital in Memphis . .

The cells in a pig’s respiratory tract contain both types of sugars, so both types of viruses can enter and exchange pieces. The infamous 1918 influenza virus, thought to have emerged from bird flu, was passed from humans to pigs in the 1920s, where it continued to evolve. The disease reappeared in humans in 1957, 1968 and 2009. In recent years, as bird flu spread through domestic flocks, the disease has gained the power to infect dozens of mammal species, including minks, raccoons, foxes, seals and porpoises. We really don’t want pigs to be next.

But the more widely the cow infections spread, the greater the chance that the virus will spread to pigs. They can become infected through contaminated equipment or if milk from infected cows ends up in their feed. Although pasteurization kills the virus in commercial milk, the raw milk remains highly contagious; it is the prime suspect in the deaths of several farm cats infected with H5N1.

“What’s a little unclear to me is what exactly happens to all this contaminated milk,” Webby said. Could some be dumped raw where other animals could ingest it?