Burundi has declared a polio outbreak after detecting its first cases of the virus in over three decades, the World Health Organization (WHO) said on Friday.
In a statement, the United Nations agency said the central African nation had detected eight cases of type 2 polio virus.
Burundian health authorities detected a case in an unvaccinated four-year-old boy in the west of the country, as well as two other children who came come into contact with him.
Five other type 2 polio samples were discovered in wastewater, the WHO said.
Polio is an infectious disease caused by a virus that infects the nervous system and can lead to irreversible paralysis.
It mainly harms young children, but can be prevented with a highly effective and very cheap vaccine.
The WHO's regional Africa director, Matshidiso Moeti, was quoted in a statement as saying that Burundi's swift detection of the cases "shows the effectiveness of the country's disease surveillance".
"We are supporting the national efforts to ramp up polio vaccination to ensure that no child is missed and faces no risk of polio's debilitating impact," she added.