The humanitarian group Medecins Sans Frontieres (MSF) has warned that the world is losing the battle against Ebola and lamented that treatment centres in West Africa had been "reduced to places where people go to die alone".
In separate remarks after a United Nations meeting on the crisis, the World Health Organisation chief said everyone involved had underestimated the outbreak, which has killed more than 1,500 people in Guinea, Liberia, Sierra Leone and Nigeria. UN officials implored governments worldwide to send medical workers and material contributions.
MSF, which has treated more than 1,000 Ebola patients in West Africa since March, was overwhelmed, said Dr Joanne Liu, its president. She called on other countries to contribute civilian and military medical personnel familiar with biological disasters.
"Six months into the worst Ebola epidemic in history, the world is losing the battle to contain it," Liu said on Tuesday at a UN forum on the outbreak. "Ebola treatment centres are reduced to places where people go to die alone, where little more than palliative care is offered."
In Sierra Leone, she said, infectious bodies were rotting in the streets. Liberia had to build a new crematorium instead of new Ebola care centres.
At the UN meeting, WHO director Dr Margaret Chan Fung Fu-chun thanked countries for helping but said: "We need more from you. And we also need those countries that have not come on board."
Later she warned that the outbreak would get worse before it got better.
US President Barack Obama urged West Africans on Tuesday to wear gloves and masks when caring for Ebola patients, and discouraged the burial practice of directly touching the body of Ebola victims, which is one way the disease has been spreading.
"You can respect your traditions and honour your loved ones without risking the lives of the living," Obama said in the brief video message.
Dr Tom Frieden, director of the US Centres for Disease Control and Prevention, said the world had its first Ebola epidemic.
The outbreak has taken a high toll on health care workers. On Monday, nurses at a major hospital in the Liberian capital went on strike. The dispute was said to be over the following day, but discussions were ongoing. And the Sierra Leone government said nurses were back at work on Tuesday after a strike at a Freetown hospital at the weekend. The government has said it will pay out all accrued hazard pay and double the allowance.
Also on Tuesday, the UN Food and Agriculture Organisation warned that food in countries hit by Ebola was becoming more expensive and would become scarcer because some farmers could not reach their fields.
Authorities have cordoned off towns. Surrounding countries have closed land borders, and airlines have suspended flights. Food imports are restricted.
Guinea, Liberia and Sierra Leone all rely on grain from abroad to feed their people, according to the UN food agency. The price of cassava root, a staple in many West African diets, has gone up 150 per cent in one market in Liberia's capital, Monrovia.
"Even prior to the Ebola outbreak, households in some of the affected areas were spending up to 80 per cent of their incomes on food," said Vincent Martin, who is coordinating the food agency's response to the crisis. "Now these latest price spikes are effectively putting food completely out of their reach."