US hospitals were this weekend granted extra powers to treat the fast-rising number of swine flu patients across the country, under a declaration of “national emergency” signed by President Barack Obama.

The action – the third declaration of special powers by federal authorities for flu this year – eases regulations for hospitals to treat patients with the H1N1 virus off site in schools and even tents, tackling surging demand on their services and limiting the risk of infecting other patients and healthcare workers.