Burundi has expelled four officials from the World Health Organization (WHO), declaring them persona non grata and ordering them to leave the country by Friday, a leaked memo from the country’s foreign ministry reveals. The decision comes days before the May 20 presidential elections and amid a global coronavirus pandemic.Bernard Ntahiraja, the foreign affairs assistant minister, did not provide an explanation for the expulsion. The WHO’s Regional Director for Africa, Matshidiso Moeti, said that the organization “remain[s] very willing to…support their [Burundi’s] response to COVID-19.” John Nkengasong, the head of the African Centers …