The Ebola outbreak in the Democratic Republic of the Congo (DRC) is continuing to outpace response efforts, with confirmed cases nearing 3,900 and no proven vaccine or specific treatment yet available for the strain behind the epidemic, the health authority said Tuesday. The outbreak has spread to 51 health zones across the provinces of Ituri, North Kivu, Haut-Uele, Tshopo and South Kivu. The report showed that 30 of 44 deaths recorded on Monday occurred in communities rather than at Ebola treatment centres. The PARTNERS treatment trial, which is evaluating experimental therapeutic options for infected patients, was operating at three sites in Ituri and had enrolled more than 50 patients. The WHO is also reviewing new animal-study data on possible cross-protection offered by Ervebo, a licensed vaccine developed against the Zaire species of Ebola virus.