Is it swine flu? Or Mexican flu? Or North American flu? Or novel flu? Names matter when it comes to the potential pandemic emerging from Mexico.

When news of the outbreak broke last week, health authorities, including the World Health Organisation, used the term “swine flu”, on the basis of genetic analysis of samples taken from patients. These showed that, although the virus responsible was a hybrid of swine, bird and human flu, it was more porcine than anything else.