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 for Disease Control and Prevention, said in a statement that he found the decision to hold elections in a time of the COVID-19 crisis irresponsible. “We have to collectively deny the virus any space to transmit,” he said.Opposition candidate Léonce Ngendakumana…