A Downing Street spokesman said:
"The Prime Minister chaired a COBR meeting on Ebola this afternoon 30 December 2014) with ministers and officials from across government and the First Minister of Scotland who joined the meeting via video conference.
"He was reassured that the robust and well-practised procedures that had been put in place were being followed and that the risk to the general public remained very low.
"He thanked the Ministry of Defence and all those involved for their work in transporting the patient to the Royal Free Hospital this morning.
"The Prime Minister also paid tribute to all those working to save lives in Sierra Leone and the important job they are doing. His thoughts are with the patient and her family and friends at this time."