David Cameron has said Ebola is the "uppermost thing" on his mind following news that the condition of British nurse Pauline Cafferkey is deteriorating.
The 39-year-old, who is being treated in isolation at the Royal Free Hospital in north London, is in a critical condition, the hospital said yesterday.
The Scottish public health nurse, who works at Blantyre Health Centre in South Lanarkshire, was part of a 30-strong team of medical volunteers deployed to Sierra Leone by the UK Government in November and had been working with Save the Children at the Ebola Treatment Centre in Kerry Town.
After returning to Heathrow Airport last Sunday she raised concerns about her temperature, but despite undergoing seven temperature checks she was given the all-clear to fly to Glasgow where she lives.
The following morning she was diagnosed with Ebola and placed in isolation at Gartnavel Hospital campus in Glasgow before being flown south.
Mr Cameron said he is listening to medical experts about whether a system of quarantine should be put in place for returning health workers.
He told BBC1's Andrew Marr Show: "It's (Ebola) certainly the thing uppermost in my mind today with Pauline Cafferkey in hospital, and all of us are thinking of her and her family.
"And also how incredibly brave these people are, not only doctors and nurses from our NHS but also people from our armed forces who have been working in west Africa in very difficult conditions."
Asked whether airport screening is failing, he said: "Her temperature was taken several times but then she was allowed to go on and travel to Scotland and what I have said very clearly is we should have a precautionary principle in place.
“If you are still in doubt, if there’s uncertainty, there’s proper arrangements for you to go to the Northwick Park Hospital in Middlesex to be observed and to have further tests there before going further.
“That is happening already, I am absolutely clear about that.
“If we need to change further, if the chief medical officer says we need a system of quarantine or anything like that, then we should put that in place.
“But it is important to listen to the medical experts and then make the decision.”
The Government’s chief medical officer, Dame Sally Davies, acknowledged last week that questions had been raised about the airport screening procedure for Ebola.
The Royal Free Hospital said in a brief statement on Saturday: “The Royal Free London NHS Foundation Trust is sorry to announce that the condition of Pauline Cafferkey has gradually deteriorated over the past two days and is now critical.”
The 39-year-old’s sudden change in condition came after her doctor described her as sitting up, eating, drinking and communicating with her family on New Year’s Day.
Dr Michael Jacobs warned that she faced a “critical” few days while she was treated with blood from a survivor and an experimental antiviral drug which is “not proven to work”.
She is the second Briton to test positive and the first to do so on UK soil after nurse William Pooley, 29, contracted Ebola while volunteering in Sierra Leone in August before getting the all-clear following treatment at the Royal Free Hospital.
The Royal Free Hospital, where Mrs Cafferkey has been treated since Tuesday, was unable to obtain ZMapp, the drug used to treat Mr Pooley, because “there is none in the world at the moment”.
Speaking about Mrs Cafferkey’s treatment, Dr Jacobs said on New Year’s Day: “At the moment, we don’t know what the best treatment strategies are.
“That’s why we’re calling them experimental treatments. As we’ve explained to Pauline, we can’t be as confident as we would like.
“There’s obviously very good reason to believe it’s going to help her, otherwise we wouldn’t be using it at all, but we simply don’t have enough information to know that’s the case.”
Public Health England confirmed on Friday that all UK-based passengers and crew aboard the two flights taken by the nurse from Morocco and London have been contacted by medical authorities and given advice.
PA