Health workers battling an Ebola outbreak in the Democratic Republic of Congo (a vast, conflict-affected nation in central Africa and one of the world's poorest countries) have threatened a full-scale strike after receiving no pay since the epidemic was declared on 15 May. Doctors at the Rwampara treatment centre in the northeastern province of Ituri — the epicentre of the outbreak — burned tyres in protest and issued a 48-hour ultimatum demanding overdue salaries and bonuses, warning they would provide no minimum service if ignored. The crisis deepens as the WHO cautioned that the true scale of the outbreak, which has killed over 700 of nearly 2,000 confirmed cases and infected at least 112 healthcare workers, may be two to four times larger than official figures suggest.