A government source in Sierra Leone said the World Health Organisation worker who contracted Ebola in the country was a Senegalese expert working for the WHO in the eastern town of Kailahun, Reuters news agency reported.
The WHO said it was the first time one of its healthcare workers had tested positive for the deadly virus.
A Swansea doctor who took leave to treat Ebola patients in Africa, is back on the wards after three weeks in isolation.
The first British case of Ebola in the outbreak in West Africa has been confirmed. So how would repatriation work are what are the risks?
In a Facebook Q&A on the Ebola virus for ITV News, an expert discussed risks, potential vaccines and what would happen if it came to the UK.