Save the Children has said a review into how a British nurse in a critical condition with Ebola had contracted the virus will “leave no stone unturned”.

British prime minister David Cameron said ebola is the “uppermost thing” on his mind following news that the condition of British nurse Pauline Cafferkey, aged 39, is deteriorating.

A Scottish nurse’s return to the UK from Sierra Leone after becoming infected with ebola is “extremely unlik-ely” to result in a large outbreak of the deadly virus in Britain, health chiefs said.

The British nurse who contracted ebola in Sierra Leone has agreed to be treated with an experimental anti-viral drug and blood from a survivor of the virus, her doctor has said.

A nurse being treated for Ebola in London could be given blood donations from fellow survivors including Will Pooley in a bid to overcome the deadly virus, the government’s chief medical officer said.