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 Organisation (WHO) 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 seek to ensure it received adequate inoculations, as neighbouring Liberia and Sierra Leone went on high alert as a precaution. "Very early this morning, the Conakry laboratory confirmed the presence of the Ebola virus," Guinea health chief Sakoba Keita said after an emergency meeting in the capital. Health Minister Remy Lamah had earlier spoken of four deaths and it was not clear why the new toll was lower. The cases marked 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 south-east region where the new cases have been found. The virus, believed to reside in bats, was first detected in 1976 in Zaire, now the Democratic Republic of Congo. Mr Keita, head of the National Agency for Health Security, said one person had died in January in Gouecke, south-east Guinea, near the Liberian border. The victim was buried on February 1 "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 confirmed Ebola on Friday, said Mr Keita. He said Guinea was now in an "Ebola epidemic situation". 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 Mr 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 Mr 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. Alfred George Ki-Zerbo, the WHO representative, said the agency was rapidly sending "crucial assets" to help Guinea. "The WHO is on full alert and is in contact with the manufacturer [of a vaccine] to ensure the necessary doses are made available as quickly as possible to help fight back." The WHO has viewed each new Ebola outbreak since 2016 with great concern, treating the most recent one in central Africa's Democratic Republic of the Congo as an international health emergency. Guinea's neighbours Liberia and Sierra Leone announced high alert despite not recording any infections as yet. The WHO said it was already helping the two countries to raise their vigilance and had already been in touch with other countries in the region including Mali, Senegal and Ivory Coast. DR Congo has faced several outbreaks of the illness, and a week ago announced a resurgence three months after authorities declared the end of the country's previous episode. The 2013-2016 West Africa outbreak speeded up the development of a vaccine against Ebola, with a global emergency stockpile of 500,000 doses planned to respond quickly to future outbreaks, the vaccine alliance Gavi said in January. Guinea, Sierra Leone and Liberia bore the brunt of the previous epidemic. Like many countries in West Africa, Guinea has limited health resources. It has also recorded about 15,000 Covid-19 cases and 84 deaths. "I'm worried as a human being, but I'm remaining calm because we managed the first epidemic and vaccination is possible," said Mr Lamah.