Page last updated at 07:18 GMT, Monday, 27 April 2009 08:18 UK Infection control experts are scrambling to respond to outbreaks of swine flu in Mexico and the US, and suspected cases elsewhere. What is swine flu? Swine flu is a respiratory disease which infects pigs. Caused by influenza type A, there are regular outbreaks among herds of pigs, where the disease causes high levels of illness but is