An outbreak of polio in Congo-Brazzaville has killed more than 100 people and paralysed hundreds more, the authorities say.
Congo-Brazzaville had previously recorded its last case of indigenous polio in 2000.
The government said the vast majority of deaths had occurred in the coastal city of Pointe-Noire.
Polio damages the nervous system, causing paralysis or death if untreated.
The New York Times quoted the director of global polio eradication at the World Health Organization (WHO), Dr Bruce Aylward, as saying: "We've got two hospitals with hundreds of paralysed people and many dead."
State television showed pictures of Congo-Brazzaville's Health Minister, Georges Moyen, visiting hospitals in Pointe-Noire, the centre of the country's oil industry.
"We only have two solutions available, vaccination and measures to ensure individual and collective health and hygiene," he said.
The authorities plan to launch a country-wide vaccination programme on Friday, starting in Pointe-Noire and the surrounding area of Kouilou, in conjunction with the neighbouring Angolan province of Cabinda.
The WHO said tests had shown that the cases were caused by a virus most closely related to one circulating in Angola.
It said the majority of reported cases and deaths had occurred in males aged over 15. Polio normally strikes young children.
Congo's director-general of health, Alexis Elira Dokekias, said the victims had either not been sufficiently immunized or not immunized at all.
Reports say women and girls may have developed some immunity to the disease through contact with babies that had been immunized.
As well as in Pointe-Noire, there have been deaths in the centre-west and south-west of the country and the capital, Brazzaville.
The WHO said countries across central Africa should strengthen surveillance for cases and respond rapidly to them. It said they should also address any gaps in polio immunization coverage.