A sixth British healthcare worker has been flown home to the UK after suspected contact with the Ebola virus.
It happened after an accidental "needle-stick injury" at a treatment centre in Sierra Leone.
Three other people have been discharged after coming into "close contact" with a confirmed British Ebola case.
The female British patient with Ebola is being cared for at the Royal Free Hospital in London. One other person is still being tested.
Meanwhile, the death-toll from the current Ebola outbreak has passed 10,000.
Between 600 and 700 UK defence personnel are based in Sierra Leone as part of efforts to tackle the largest ever outbreak of Ebola.
One British military healthcare worker was diagnosed in Sierra Leone and was flown back to the UK on an RAF plane on Thursday.
She was then taken to the special isolation unit at the Royal Free, where two British nurses infected with Ebola - William Pooley and Pauline Cafferkey - were successfully treated.
Also on board the RAF flight were two colleagues who had also come into "recent close contact" with the diagnosed woman.
They have now been discharged as there was no sign of the virus in their bodies.
A further two close contacts were flown to Newcastle Royal Infirmary on Friday. One has been discharged, while the other is still being tested.
In a separate incident, the sixth person - a healthcare worker - was pricked with a needle while caring for a patient. It is one of the most dangerous ways of being exposed to the virus because there is direct access to the bloodstream.
This individual has also been taken to the Royal Free Hospital.
Dr Jenny Harries, from Public Health England, said: "All appropriate support has, and will continue to be offered, to these six individuals. Our thoughts are with all the healthcare workers, and their families, affected at this time.
"The UK has robust, well-developed and well-tested systems for managing Ebola. All appropriate infection control procedures continue to be followed to minimise any risk of transmission. There remains no risk to the general public's health and the overall risk to the UK continues to be very low."
Prof Dame Sally Davies, Chief Medical Officer, said: "The UK has robust, well-developed and well-tested systems for managing Ebola virus disease.
"All appropriate infection control procedures have, and will continue to be, strictly followed to minimise any risk of transmission."
Dr Ben Neuman, a virologist at the University of Reading, said flying the patient back to the UK offered the best chance of recovery.
"The Royal Free Hospital has a 100% record in treating Ebola cases so far, let's hope that doesn't change.
"While the new batch of ZMapp is not yet available, she could be treated with favipiravir, which has shown some early promising results in West African Ebola clinics.
"She may also be given antibody-rich serum from Ebola survivors to knock down the amount of virus in her blood while her immune system is learning to fight Ebola."