Sierra Leone has confirmed a new case of Ebola, its second in less than a week, marking a setback in efforts to end a two-year epidemic that has killed more than 11,300 people in West Africa.
Health ministry spokesman Sidi Yahyah Tunis described the new patient as a 38-year-old woman, a relative who had helped care for the earlier victim Mariatu Jalloh.
Jalloh died from the disease on January 12, and tested positive for Ebola posthumously.
In November, Sierra Leone was declared Ebola free after 42 days with no cases.
Guinea was declared free of Ebola on Tuesday after more than 2,500 people died from the virus in the west-African nation.
The declaration by authorities and the UN World Health Organization (WHO) was met by a mixed reception, with the outbreak not only claiming lives but also damaging the country's economy, health and education sectors.
The announcement means Liberia is now the only country still awaiting a countdown for the end of the epidemic.
There were more than 3,800 cases of Ebola in Guinea out of more than 28,600 cases worldwide, which have caused 11,300 deaths, according to the WHO.
A country is declared Ebola free 42 days after the recovery or death of the last patient and if there are no new infections.
A 15-year-old boy has died of Ebola in Liberia, which was previously declared free of the virus.
The boy's father and brother have also tested positive for the virus and have been taken to a treatment centre along with his mother and two other siblings.
Health officials have identified nearly 160 people who might be at risk of the disease, including 10 healthcare workers who came into direct contact with the boy.
The source of the virus is being investigated but it is the first death in Liberia since July.
Liberia has recorded more than 4,800 Ebola deaths and more than 10,600 cases since this year's outbreak.
It was first declared Ebola-free on May 9, but new cases emerged in June resulting in two deaths.
The World Health Organization declared the country Ebola-free again on September 3.
The World Health Organisation (WHO) failed to act quickly to contain the spread of the Ebola virus, a critical new report has said.Read the full story ›
A case of Ebola has been confirmed in a 10-year-old boy in Liberia - which was previously declared free of the disease.
The boy is currently being seen by medics at the treatment center on the outskirts of the capital Monrovia.
Liberia was first declared Ebola-free on May 9 - but there was a resurgence of the disease in late June infecting four people and two later died.
The country was again declared Ebola-free on September 3 by the World Health Organization.
Chief Medical Officer Dr. Francis Kateh told AP on Friday the boy, a resident of the eastern Paynesville district of Monrovia, was taken to the Ebola treatment unit late Thursday.
He confirmed the boy had Ebola.
BREAKING: Health authorities report 1 confirmed Ebola case in Liberia, previously declared Ebola free.
Nurse Pauline Cafferkey has fully recovered from meningitis related to the Ebola virus and has been released from isolation.Read the full story ›
There have been no new reported cases of the virus in the West African nation for more than 42 days.Read the full story ›
Nurse Pauline Cafferkey has made a "significant improvement" after becoming unwell with meningitis caused by the Ebola virus.
The 39-year-old from Glasgow has been receiving treatment in the Royal Free Hospital's high level isolation unit since October 9 and was at one point in a critical condition.
On Wednesday, the hospital's Dr Michael Jacobs revealed she had not been reinfected with Ebola, but that the virus had re-emerged to cause meningitis.
"I'm really pleased to tell you that in the last few days she has made a significant improvement," Dr Jacobs told a press conference.
He said Ms Cafferkey was still bed-bound but was talking freely and able to eat a little.
Dr Jacobs said staff were "delighted" with her progress but that she had a "long recovery ahead of her" and would remain in hospital for some time.
Nurse Pauline Cafferkey's condition "has improved to serious but stable" after being treated for Ebola for a second time, Royal Free Hospital has said.
The 39-year-old from Glasgow has been receiving treatment in the hospital's high level isolation unit since 9 October due to a late complication of her previous infection.
Nurse Pauline Cafferkey is likely to be suffering a reaction to the Ebola virus, according to a leading expert.
Professor John Oxford said a very small amount of the virus could be lingering in the nurse's body despite the treatment she originally received.
Prof England said: "Lots of viruses, even the more common ones that we get in England like mumps, measles or used to before the vaccine came in Rubella things like that, children would recover - acute phase - but then months later, maybe even a year later, they'd be seriously ill again.
"They wouldn't have the rash, wouldn't have the original disease as such, they'd have a reaction to that original disease, maybe because of their own immune reaction.
"Pauline is surviving because of her immune system but you can get an overreaction. That's possibly causing some of the symptoms now."