A 16-year-old girl died in Sierra Leone today after catching the Ebola virus, the National Ebola Response Centre (NERC) confirmed.

The victim came from the city of Makeni in the northern Bomabli district, where no new case had been reported for 169 days.

According to AFP, the girl was hospitalised on Saturday, after showing initial symptoms on Tuesday. It was not until earlier today that she tested positive for the disease, however.

The cause of infection is currently unknown, and those at high risk, including her parents, teacher and classmates are currently being monitored.

NERC said the news was “disappointing” , but added that it had worked with its technical partners – the Ministry of Health and Sanitation and the WHO – to prepare for this, and urged the public to “remain calm”.

Bombali district has not reported a case for 169 days, however, this does not mean it is not ready to respond. With established structures and processes already in place, the NERC and its partners have already made adequate preparations.

The news comes as a major blow to the west African nation, which has been heading towards a full recovery from the epidemic that claimed thousands of lives in the region last year.

No new cases had been reported in Sierra Leone for two weeks, and on 24 August President Ernest Bai Koroma held a ceremony in celebration of the country's last known Ebola patient being discharged from hospital.

To officially be declared free from the disease, the World Health organisation says a country must have no new cases for 42 days after the last confirmed sufferer has tested negative twice.