West Africa is facing the first reported resurgence of Ebola since the end of a devastating outbreak in 2016. Guinea Conakry is dealing with a situation described by the national health authorities as an "epidemic" after seven cases were confirmed.
Guinea and the World Health Organisation say they are better prepared to deal with Ebola than they were five years ago, because of progress on vaccines.
The WHO said it would rush assistance to Guinea and seek to ensure the country received adequate inoculations. Neighbouring Liberia and Sierra Leone have been put on high alert as a precaution against the spread of the haemorrhagic fever.
"Very early this morning, the Conakry laboratory confirmed the presence of the Ebola virus," Guinea health chief Sakoba Keita said on Sunday after an emergency meeting in the capital.
The cases mark the first known resurgence of Ebola in West Africa since a 2013-2016 epidemic that killed more than 11,300 people, the worst involving the virus on record.
That epidemic also began in Guinea in the same southeastern region where the new cases have been found.
The virus, believed to reside in bats, was first identified in 1976 in Zaire, now the Democratic Republic of Congo.
Funeral possible source of infection
Keita, head of the National Agency for Health Security, said one person had died in late January in Gouecke, southeastern Guinea, near the Liberian border.
The victim was buried on 1 February "and some people who took part in this funeral began to have symptoms of diarrhoea, vomiting, bleeding and fever a few days later," he said.
Some samples tested by a laboratory set up by the European Union in Gueckedou in the same region revealed Ebola on Friday, said Keita.
He added that Guinea was now in an "Ebola epidemic situation".
Rapid diagnosis now available
Patients have been isolated and an investigation has been ordered to determine the home villages of all who took part in the burial so that contact tracing can be carried out, said Keita.
Experts will also work to determine the outbreak's origin, which could be a previously cured patient whose disease relapsed or transmission by "wild animals, in particular bats", said Keita.
According to the health chief, diagnosis time has been reduced to less than two weeks compared with three-and-a-half months in 2014.