Steps from a chance at salvation, or at least a less excruciating death, Comfort Zeyemoh walked slowly from the Ebola treatment center on Saturday. It was one of only three in a city devastated by the lethal virus. And it was nearly full.

Zeyemoh, 22, was not sick enough to gain entry, though she had started vomiting the night before and was feeling weak. Those are telltale signs of Ebola.

“They sent us here for a checkup,” her boyfriend, Moses Sackie, said outside the facility run by the aid group Doctors Without Borders. “Now they are telling us to wait for three days.”

With each day, the small group of caregivers trying to cope with the worst outbreak of Ebola on record falls further and further behind as the pace of the virus’s transmission rapidly accelerates. Health facilities are full, and an increasing number of infected people are being turned away, left to fend for themselves.

The epidemic has killed more than 2,200 people in five African countries and now poses a threat to Liberia’s “national existence,” according to its defense minister. The World Health Organization says the epidemic’s growth has been “exponential” in recent weeks, especially in Liberia.

The Doctors Without Borders center in Paynesville, on the outskirts of Monrovia, has 160 beds and is scheduled to add 25 on Monday. It needs 1,200 — and a corresponding increase in staff — to cope with the epidemic, said Sophie-Jane Madden, a spokeswoman for the organization. As Ebola begins to race through this city, that number is certain to increase.

“We’re just running behind the virus, aren’t we?” Madden said. “And taking the sickest people because we don’t have the capacity” for more. On Friday, 23 people were admitted, 25 were turned away, nine died and seven were released after recovering, she said.

The sick arrive each day, hopeful that their timing and symptoms will get them past the gate. Even so, 7 in 10 will die inside, slightly better odds than the 9 in 10 who are dying in the community, Madden said.

On Saturday morning, Josh Tugbeh’s luck did not hold. He felt sick and weak, with pain in his joints that made it difficult to walk. “I come here and they say they are not accepting patients,” he said outside the ELWA 3 center, as the Doctors Without Borders facility is called. “I want to go back home, but I am not able to walk to go home.”

The scene was similar at the JFK treatment center run by the Liberian government in another Monrovia neighborhood, where Jatu Zombo cradled her 5-year-old son, Foday, beneath a tarp set up to block the sun. A few feet away, her 10-year-old boy, Zen­nah, sat on a paint can. Both children were listless and visibly ill. They felt cold and had been vomiting. Their father had died four days earlier, and Zombo, 36, spent days calling for an ambulance that never came. Finally, her brother paid someone $20 in U.S. currency to bring them to JFK.

But the children could not get in. “No one has spoken to us,” said Zombo’s brother, Abraham Sesky. “So we are just sitting. We don’t know.”

At the former Redemption Hospital, now a holding center for the sick and the dead where no treatment is offered, an ambulance pulled up to the front gate Saturday afternoon and dropped off two adults and a girl. The ambulance driver said the child’s name was Cynthia and that she was 10 years old.

Weak and wobbly, the girl walked a few steps before she lay on the concrete. Cynthia and the others could not be brought inside, because workers were loading bodies, wrapped in white plastic body bags, into the back of a pickup truck. The area needed to be disinfected first.

As a small crowd gathered on the street of the New Kru Town slum, Cynthia called to the ambulance driver a short distance away, saying she wanted to go home. The driver told her not to move, to wait for the people inside to get to her. A woman began to wail, and soon security personnel dispersed the crowd.

Around the corner and down a block or two, another small crowd had grown angry at the delay in retrieving a man’s body that lay under a tree outside some homes. Residents said that it had been there since Friday and that Redemption officials had failed to respond to repeated calls to come get it. Ebola, a hemorrhagic disease, is at its most lethal in the body fluids that leak from corp­ses.

“They have not come to spray” disinfectant in the area around the corpse, Powell Johns, a preacher, said angrily. “That’s wrong. They’ve got to do their jobs.”

The group led some American and French journalists to the body. The tactic worked. Soon, workers in front of Redemption were donning full-body protective gear and heading over to collect the corpse.

Across Monrovia, such breakdowns in basic services are common. Schools are closed. Aside from the delivery of children, it is almost impossible to get any kind of medical care that would require a hospital, because Ebola has overwhelmed the system.

Few people are working. They have been told to stay home, to help slow transmission of the virus, which means that no money is coming in for basics such as food. People say they are relying on handouts from family and friends and hustling for a few dollars.

The United Nations has estimated that it will cost at least $600 million to fight the epidemic and address the economic and social devastation suffered by the hardest-hit countries — Liberia, Sierra Leone and Guinea.

The U.S. government has spent more than $100 million in the region, and additional requests for aid, if approved by Congress, would bring the total commitment to more than $250 million. Critics called the U.S. response inadequate after the Pentagon said last week it is sending a 25-bed field hospital to treat health-care workers exposed to Ebola. Senior administration officials have suggested that additional assistance is forthcoming.

Mohamed Conteh, a tailor whose tiny shop sits just around the corner from the JFK treatment center, said his business has dwindled almost to nothing since the Ebola facility opened.

“Since the center came, there’s nothing here, because people are afraid to come,” he said.

“Some days I go home and there is no money,” he added. “I have to ask others to feed my family.”

Francis Sampson, who lives in a tiny home next to the JFK gate, said he used to earn $120 a month working for a cellphone company. Now, he has nothing. “My parents go to church,” he said, “and the church gives them food.”

Not far away, Boimah Fully, 38, said he used to pick up gas at an oil refinery and sell it at the side of the road. Now he and his five brothers are living on rice they cadge here and there.

One day, he declared, Liberia’s latest crisis will end. “Ebola will go,” he said. “I don’t know when. But Ebola will go.”

Lena H. Sun in Washington contributed to this report.