Health authorities quarantined hundreds of people in northern Sierra Leone after a 16-year-old girl died of ebola in an apparent case of sexual transmission, the first confirmed death from the virus in the district for nearly six months.

The spread of ebola seems to have stabilised in Guinea, one of three West African states worst-hit by the disease, but a lack of beds and resistance in affected communities means its advance continues elsewhere, the World Health Organisation said.

Sierra Leone says a nationwide lockdown has revealed that an Ebola outbreak is worse than thought and ordered three more transmission hotspots to be cordoned off.