Peter Salama, deputy director-general of emergency preparedness and response at the WHO, said in Geneva, Switzerland, on Friday that it's "going to be tough and it's going to be costly to stamp out this outbreak."There have been 34 cases of Ebola virus disease reported during the past five weeks, the WHO said Friday. Of those, two have been confirmed using laboratory tests, 14 are suspected, and 18 — who are deceased — are considered probable for the disease. Three of the patients are health care workers. "The number of suspected, probable and confirmed cases is significant, so we are very concerned, and we are planning for all scenarios, including the worst-case scenario," Salama said.Ebola virus disease, which most commonly affects people and nonhuman primates such as monkeys, gorillas and chimpanzees, is caused by one of five Ebola viruses. On average, about 50% of people who become ill with Ebola die.The disease is endemic to the Democratic Republic of Congo, and this is the nation's ninth outbreak since the discovery of the virus in the country in 1976.The latest outbreak is occurring in the Bikoro health zone, 400 kilometers (about 250 miles) from Mbandaka, the capital of Equateur province.Bikoro health zone has a population of about 163,000, with three hospitals and 19 health centers, most with limited functionality, according to the WHO.Given the remote location of the outbreak, Salama said, response efforts will be extremely challenging. "It is a dire scene in terms of infrastructure," he said."To give you a sense, we are talking about an area that is 280 kilometers even from the provincial capital of Equateur," he said.The WHO is working with authorities in Congo and is in discussions with the World Food Programme to arrange airlifting supplies to the affected areas. UNICEF is also making doctors available as well as sanitation and hygiene specialists to help contain the outbreak.The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission, either through direct contact with bodily fluids such as blood or secretions or contact with materials that are contaminated with these liquids.Personal protective equipment, body bags, boxes for transportation and interagency emergency health kits will all be sent to the affected region Saturday, the WHO said. Two mobile laboratories will also be deployed. Médecins Sans Frontières is setting up four five-bed mobile isolation units to increase the hospital bed capacity in Bikoro, which is currently 15 beds, according to the WHO. Initial control efforts are focusing on tools such as surveillance and monitoring, safe burials and case management. Vaccines along with doctors and epidemiologists are on standby in case they are needed, according to the UN.If they are needed, "WHO is in discussions with the government and, if pertinent, will seek approval from the national regulatory authority and the Ethics Review committee to use vaccines against Ebola as part of the response," spokesman Tarik Jasarevik said.The current vaccine against Ebola is experimental and not a licensed product. Salama pointed out that its use also comes with many challenges, as the vaccine needs to be stored long-term at temperatures between minus 60 and minus 80 degrees Celsius (minus 76 to minus 112 Fahrenheit)."This is not a simple logistical effort; it's not like doing a polio campaign with oral polio vaccines, where we get it immediately out to the field. This is a highly complex sophisticated operation in one of the most difficult terrains on Earth," Salama said.Toward that effort, the organization released $1 million from its emergency fund to launch a rapid response to the outbreak. "The estimated budget for the international response is US $18 million for a three-month operation," the WHO said Friday. WHO Director-General Dr. Tedros Adhanom Ghebreyesus will travel to the Democratic Republic of Congo over the weekend "to take stock of the situation and direct the continuing response in support of the national health authorities," according to a statement from the WHO. Nine neighboring countries are on high alert, Salama said, but the WHO says the current risk of disease spreading to them is low.West Africa experienced the largest recorded outbreak of Ebola over a two-year period beginning in March 2014; a total of 28,616 confirmed, probable and suspected cases were reported in Guinea, Liberia and Sierra Leone, with 11,310 deaths, according to the WHO.
CNN's Susan Scutti contributed to this report.