The battle against Ebola is winnable, public health officials say, but a growing chorus of institutions and experts is warning this week that an insufficient global response to West Africa's epidemic may put a solution to the crisis out of reach.

The disease is spreading uncontrollably in Liberia and Sierra Leone, has now spread beyond Lagos in Nigeria, and has just been detected in a fifth West African country, Senegal. (Related: "As Ebola Crisis Spreads in West Africa, Liberia's Deterioration Stands Out.")

At a news conference Wednesday, the head of the World Health Organization and a United Nations senior system coordinator for Ebola disease renewed pleas for more support from the world's nations, while praising current efforts by the United States, the United Kingdom, Uganda, South Africa, and some others.

The problem basically comes down to a lack of trained volunteers, the officials said. (Related: "Doctors and Nurses Risk Everything to Fight Ebola in West Africa.")

"Without the support of foreign medical teams, it is very difficult to mount a response [on] the scale that is in keeping" with the scope of the problem, said Margaret Chan, the WHO's director-general. She said foreign medical teams have been "very far and few between."

It takes 200 to 250 health care providers to care for 80 Ebola patients at one center, said Keiji Fukuda, the WHO's assistant director-general for health security. Additional people are needed to drive patients to medical centers, to bury the dead, and to seek out contacts of sick people to help contain the disease.

"As the outbreak gets bigger, we estimate there will be the need for several thousand people taking care of patients among the many different countries," Fukuda said. "It's not a static number and it will depend on the size of the outbreak."

View Images *Suspected, probable, and confirmed cases and deaths as of August 26, 2014. Senegal data as of August 29, 2014. DANIELA SANTAMARINA AND KELSEY NOWAKOWSKI, NG STAFF. SOURCE: WORLD HEALTH ORGANIZATION

The public health officials declined to name specific countries they think need to do more other than to point generally to nations with the capacity and experience to respond to biohazards.

Epidemic Won't Burn Out

"States with those capacities know who they are," Michael Goldfarb, a spokesperson for the humanitarian organization Doctors Without Borders/Médecins Sans Frontières, said Wednesday. "We hope they will hear both our plea and that from the frightened populations affected by the outbreak."

Joanne Liu, international president of the MSF, told UN officials Tuesday that the world is losing its battle with Ebola because of inaction.

"Leaders are failing to come to grips with this transnational threat," she said. "We cannot cut off the affected countries and hope this epidemic will simply burn out. To put out this fire, we must run into the burning building."

A detailed World Health Organization plan for fighting Ebola, released last week, looks great on paper, Liu said, but realities on the ground aren't going to change without action. What's needed is more well-trained, well-equipped staff treating patients and gumshoe epidemiology to track down and isolate potential new cases.

The U.S. Centers for Disease Control and Prevention (CDC) also called this week for more aggressive international action against Ebola. At a Tuesday news conference, CDC Director Tom Frieden, just back from a tour of the hardest-hit West African nations, praised local health care workers and asked for more help from his counterparts across the world. (Related: "Q&A: Photographer in Liberia's Ebola Zone Encounters the Dead—But Also Moments of Joy.")

"I wish every world leader could see what I have seen," he said in prepared remarks. "Stopping this outbreak is more than any one nation can do ... The sooner the world comes together to help West Africans, the safer we all will be."

Since July, the CDC has sent more than a hundred experts to the region to assist with surveillance, health education management, and tracking down contacts of sick people, among other things. The U.S. Agency for International Development (USAID) has paid more than $21 million for health equipment, food, training, and emergency supplies in West Africa.

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