In this Nov 20, 2014 file photo, a Medecins Sans Frontieres (MSF) Ebola heath worker is sprayed with disinfectant as he leaves the contaminated zone at the Ebola treatment center in Gueckedou, Guinea. (JEROME DELAY / AP)

CONAKRY, Guinea－West Africa faced its first known Ebola resurgence since the end of a devastating outbreak in 2016 on Sunday, with Guinea responding to what its health chief called an "epidemic" after seven cases were confirmed.

Despite the COVID-19 pandemic stretching health resources across the world, Guinea and the World Health Organization say they are better prepared to deal with Ebola now than they were five years ago because of good progress on vaccines.

The WHO said it would rush assistance to Guinea and ensure it received adequate inoculations, as neighboring Liberia and Sierra Leone went on high alert as a precaution.

The cases marked the first known cases of Ebola in the region since a 2013-16 epidemic that killed more than 11,300 people, the worst involving the virus on record

"Very early this morning, the Conakry laboratory confirmed the presence of the Ebola virus," Sakoba Keita, head of Guinea's National Agency for Health Security, said after an emergency meeting in the capital.

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Health Minister Remy Lamah had earlier spoken of four deaths and it was not immediately clear why the new toll was lower.

The cases marked the first known cases of Ebola in the region since a 2013-16 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.

Keita said one person died in late January in Gouecke, southeastern Guinea, near the Liberian border.

'Epidemic situation'

The victim was buried on Feb 1 "and some people who took part in this funeral began to have symptoms of diarrhea, 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 Guinea was now in an "Ebola epidemic situation".

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Patients have been isolated and an investigation was ordered to determine the home villages of all who took part in the burial to carry out contact tracing, said Keita.

Experts will 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.

The health chief said diagnosis time has been reduced to less than two weeks compared with three-and-a-half months in 2014.

"We are going to rapidly deploy crucial assets to help Guinea," WHO official Alfred George Ki-Zerbo said.