Is this the start of a global flu pandemic?

Not yet, but it almost certainly will be. The World Health Organisation says the new H1N1 strain of swine flu spreading from Mexico brings a "significant risk" of a pandemic and has stepped up surveillance, alongside national bodies such as the US Centres for Disease Control. The WHO emergency committee upgraded its official alert to level 5 on Wednesday 29 April – one step short of declaring a full-scale pandemic. This means abandoning efforts to contain the virus’s spread, to focus instead on mitigating its impact.