In a setback for Sierra Leone’s bid to gain Ebola-free status, the National Ebola Response Centre (NERC) has disclosed on Monday that a woman, who died last week in northern Sierra Leone tested positive for Ebola.

There had been celebratory scenes last week when the country’s last known Ebola patient was released from hospital in the central city of Makeni after being cured of the virus, raising hopes the west African nation may finally have beaten the devastating epidemic.

Sources contacted by AFP confirmed that the woman was in her mid-60s and lived in Sella Kafta village in Kambia District.

The swab taken after her death last Friday confirmed she had contracted Ebola.

She had not travelled to either Liberia or Guinea, two other countries also blindsided by the worst outbreak of Ebola in history, which has killed some 11,300 people since first emerging in December 2013 in Guinea.

“We have sent a team from here to Sella Kafta village and we have already identified ten high-risk contacts that we are focusing on to stem any possible transmission,” the NERC’s communication director Sidi Yahya Tunis said in an interview with a local radio station.

“We have already isolated the high-risk contacts and are assessing whether the village will be isolated if need be,” he added.

Tunis also said that a World Health Organization team which successfully tested an Ebola vaccine in Guinea that has been billed as possibly marking “the beginning of the end” of the virus would join NERC in Kambia to vaccinate contacts of the latest victim to “stop any possible train of transmission”.

Tunis said people should “remain calm and not be frustrated over the development”.