09:32DiscoveryPatient zero: Back from the brinkBBC World Service Duration: 41 minutes Tue 25th May 2021, 09:32 on BBC World Service West and Central AfricaAvailable for over a yearListen nowWhy did children in PNG contract polio in 2018? Show more GenresFactualScience & NatureFormatsMagazines & ReviewsBrandDiscovery Source: BBC Online