How did swine flu start?

Dr Rob: We actually don’t know exactly how it started, however, the first outbreaks were spotted in Mexico and it’s quite likely that there had been ongoing cases for a couple of months by the time it was detected by doctors. The reason it wasn’t picked up that quickly is probably because in most people swine flu caused a relatively mild illness and as a result not that many people ended up going to see their doctor who could put two and two together and realise there was an outbreak going on.

What’s even stranger about the start of swine flu is that although all the news coverage was about Mexico, it was actually scientists in America who actually detected the new ‘swine flu’ strain in two American children. Quite often it takes a while before we get a final picture of how a new strain started and although we’re unlikely to ever find out who was the first person to be infected with this new strain, scientists think that the virus first entered humans around september 2008 – www.nature.com/news/2009/090505/full/459014a/box/1.html