"Look!" says Stefania Poggi. "They've made inflatable rafts."

Two dozen boys are splashing in a massive, muddy pool surrounded by 30-foot-tall earthen banks. They're jumping on grain sacks that they've filled with plastic bottles to make them float.

Poggi manages the Doctors Without Borders operation in the largest refugee camp in South Sudan.

The 35-year-old Italian is standing on the banks of the drainage ditch, which was bulldozed through the middle of the camp to alleviate flooding.

She beams with delight at the kids' ingenuity. Then she snaps back into her role as a health care professional. It's probably a terrible idea that the kids are swimming in runoff from the camp, she says. "Could spread any kind of disease."

But there are worse risks for kids in South Sudan right now than a murky drainage pond. They could be child soldiers. They could be victims of rape. They could be dying of starvation or succumbing to a parasitic infection that would be easily treatable if the health care system hadn't collapsed.

The hospital Poggi runs in the southwest corner of the camp is packed with dozens of kids suffering from severe malnutrition, malaria, tuberculosis and diarrhea. The facility has only two doctors to oversee its 170 beds.

There was a hepatitis E outbreak recently, and the hospital has isolation tents for measles and cholera. So if some of the kids have turned a drainage ditch into a makeshift swimming pool, so be it. The Italian aid worker isn't too worried about the risk.

"It's good to get out [of the hospital] into the camp," Poggi says with a shrug, a slightly mischievous smile lingering on her face.

Strangers In Their Own Land

This camp where she has spent the past two months is officially known as the United Nations Protection of Civilians Site Bentiu. More than 120,000 South Sudanese have sought refuge inside this compound, which is just outside the ransacked town of Bentiu. The U.N. categorizes them as "displaced persons" rather than refugees because they haven't fled out of their own country.

From the outside, the camp looks like a post-apocalyptic prison. It stands on a dusty, arid plain and is ringed by bulldozed mounds of dirt topped with razor wire. Each wall is more than a mile long. U.N. peacekeepers man gun turrets along the earthen barricades.

In the rainy season, the camp turns into a giant mud pit. In the dry season, the temperature hits 115 degrees and it becomes an expanse of dust.

Residents aren't here because they want to be. They're coming because they're afraid they'll be killed if they don't. For the past 2 1/2 years, a brutal civil war has convulsed South Sudan. Late in 2013, the president and vice president, who are from rival ethnic groups, took up arms against each other. Both of their armies have been accused of rape, murder and torture.

"I saw people killed in front of me," says 26-year-old Tavitha Nyaluak, sitting in the darkness of her shelter in the camp. Her 2-year-old daughter is in her lap, curled against her breast. "There was a lot of fighting. We were scared away from our village and hid across the river." She arrived at the camp in June 2014. "I thank God that I came here. We could be killed if we stayed in the bush. Now I'm getting food for the children."

The Toll Of War

Before the war, South Sudan was one of the poorest countries in the world. Now it's even poorer. The fighting pushed the country deeper into crisis, destroying crops, homes and the nation's minimal infrastructure. Entire villages were burned to the ground. Hospitals were torched and patients massacred in their beds. Foreign medical teams and aid workers were forced to evacuate.

Originally the Bentiu camp was an ordinary U.N. base. As the war raged, people fled to the compound to escape the fighting. The peacekeepers kept extending the fortified perimeter farther out across the scrubland. The new residents kept building more huts from plastic sheeting, reeds and salvaged lumber.

Even before the civil war erupted, Doctors Without Borders had been working in Bentiu. The group moved into the camp soon after the town was looted and burned to the ground in 2014. Human rights groups accuse forces loyal to President Salva Kiir of carrying out a scorched-earth policy in areas dominated by rival ethnic groups. Bentiu is one such area. The 170-bed hospital erected by Doctors Without Borders is known universally in the camp as MSF, the abbreviation for the French name of the group, Medecins Sans Frontieres.

Today, the MSF facility is the only functioning hospital in this part of the country. Each ward is in a large white tent. In most wards, 20 beds line a center aisle. Particularly in the pediatric wards, entire families — mother, father, kids — sleep in the same hospital bed. The hospital is run by roughly three dozen foreign workers and 500 local staff. The South Sudanese workers are camp residents. The foreign aid workers come for various amounts of time: nurses and midwives for six months; doctors, for three or four months.

Making Rounds With Dr. Nav

One of the two doctors is Navpreet Sahsi, a 34-year-old emergency room physician from Toronto.

He's a big personality on the wards, where he's known as Dr. Nav. Kids rush up to greet him. The South Sudanese nurses gravitate toward him on his rounds. He jokes with a woman who just had twins that they're going to share the newborns. "One for you, one for me! Right?" He pantomimes snatching one of the babies like a football. Everyone laughs.

Dr. Nav is in the middle of his morning rounds, going to one of the isolation wards to check on a 35-year-old woman with a mysterious rash.

"When she came, we all were kind of scratching our heads," he says, pulling on a pair of latex gloves. "I've never seen a rash like this in my life."

The patient is covered head to toe in blisters. Some of the sores are open. Others have scabbed over. Blood and pus stain the sheet of her mattress.

"Her story is that she's from Leer and she escaped in May or June [2015]," he says. Leer is a small town about 70 miles south of Bentiu near the banks of the White Nile.

After Leer was ransacked by soldiers, the woman and a group of women and children hid in a swamp. They'd spend most days submerged like hippos, just their heads above water. At night they'd come out to search for food and a dry place to sleep. The next day they'd slip back into the swamp so the soldiers wouldn't be able to find them.

Dr. Nav is keeping her in an isolation ward — not because she's contagious but to give her some privacy and because he's worried her appearance might scare the other patients. He has given her a topical cream to soothe her skin. Despite not having a clear sense of what's causing the rash, he thinks it might respond to steroids.

He's also worried that an infection will take hold in her open wounds. "We don't live in a very clean environment. Flies are going in and out of her wounds, and we can't really do much to stop that except for encouraging her to use the mosquito net," he says. "But her risk of a secondary infection is quite high, which is why I just gave her antibiotics."

She's part of a steady stream of patients. Sometimes the sheer volume of patients can be overwhelming. Dr. Nav recalls doing rounds one time with a South Sudanese assistant. After checking the vital signs of an elderly woman in one of the beds, Nav declared that she was looking remarkably better than the day before. His assistant looked puzzled. "That woman yesterday died," Nav remembers the assistant saying. "This is a new one."

South Sudan is one of the most remote countries in Africa. It's slotted like a puzzle piece in the heart of the continent. All told, the civil war has forced more than 2 million South Sudanese from their homes. Hundreds of thousands have fled to neighboring countries: Ethiopia, Kenya, Uganda, the Democratic Republic of Congo, the Central African Republic, and even their former adversary, the Republic of Sudan.

But most of the displaced, like the woman with the full-body rash, remain inside the country.

Dr. Jiske Steemsna: High Highs And Deep Lows

The other doctor at the hospital is Jiske Steemsna, a pediatrician from the Netherlands. She is making rounds on a ward filled with malnourished children. One of them is a 3-year-old who weighs just 15 pounds and has malaria.

The child swings in and out of consciousness. Steemsna at one point jams a needle all the way into the bone marrow of the girl's leg to start an IV. The little girl barely flinches.

Steemsna says at first it was very hard to adjust from working in a hospital in Amsterdam to working here.

"Just getting used to the mortality, the children dying, every two to three nights being on call," Steemsna says. "At first I had nightmares, just not feeling comfortable. But that lasted only the first week, I think."

Steemsna sings in an a cappella group back in Holland. On the same ward as the malaria patient, Steemsna sings in French with a girl who appears to be 8 or 9 years old. The child howls with laughter every time the doctor joins in.

A week after being admitted, the girl with severe malaria dies, despite repeated efforts by Steemsna and the rest of the staff to revive her. The Dutch doctor at first curtly demands to know what happened and asks if the staff had done everything possible to save the child.

Her anger eventually subsides. Later she says it's really hard when a child dies, but she's coming to grips with the fact that she can't save everyone. And it's part of the reality here. "Now I can't imagine going back to work in Amsterdam to an academic hospital," says Steemsna, who has been in South Sudan for two months. "I feel happy being here. It's hard work. It has really high highs and deep lows, but I'm happy to be here."

Malaria is one of the most widespread illnesses. Pneumonia and tuberculosis are also common. There are entire wards of malnourished children. There's a maternity ward and a tent for women and girls who have been raped.

When the war outside the camp's walls flares up, the hospital treats gunshot and stab wounds — a reminder that even though the camp itself is bleak, it's a safe haven compared with the chaos outside.

'We Sudanese Are Tired Now'

The hospital operates 24/7. As the sun goes down, mosquito nets are unfurled over beds. The lights in the wards are dimmed, but the tents still glow in the darkness.

Rebecca Nyarik, 29, has brought her 11-month-old son to the hospital. He's had a fever for several days that doesn't seem to be waning. Nyarik came to the camp two months ago to get away from a round of fighting that flared up in Leer, where she lived.

The irony is that the South Sudanese civil war — the fighting that she fled — on paper is officially over. Both sides signed a peace deal in August 2015. But sitting with her son asleep in her arms, Nyarik says there is no peace in South Sudan. Gunmen continue to terrorize many parts of the country. The night before Nyarik brought her son to the MSF hospital, government soldiers attacked a camp on a U.N. base in the neighboring Upper Nile state. That attack left 29 people dead, injured 140 and forced tens of thousands to flee their shelters. Among the dead were two South Sudanese employees of Doctors Without Borders.

"If this is peace, why do people still continue the war? I myself think there is no peace," Nyarik says, her anger barely contained. "If you have peace, then no fighting. I ask you why do Sudanese continue to die? Why?"

Nyarik says if she leaves the camp, she and her son could be killed by anybody – government soldiers, rebel soldiers, unaligned militias.

"I myself I can't go out [of the camp] until the peace is peace."

It's late, close to midnight. Most of the patients on the wards are asleep. At this time of night, calm settles over the hospital.

Nyarik shifts on the wooden bench and hoists her dozing infant farther up her chest.

"We Sudanese, we are tired now," she says.

Yet there is not much hope for peace in the near future. A March report from the U.N. Human Rights Office accused both sides in the conflict of gross violations of human rights, including the systematic rape of civilians. The report alleged that government soldiers and militias aligned with the president were the worst perpetrators.

"This is one of the most horrendous human rights situations in the world, with massive use of rape as an instrument of terror and weapon of war," U.N. High Commissioner for Human Rights Zeid Ra'ad Al Hussein said in a statement when the report was released in March. "Yet it has been more or less off the international radar."

The report found that some soldiers weren't actually paid but instead were given permission to take whatever they wanted, including sex from the villagers they conquered.

The U.N. said some of the gravest violations of human rights in South Sudan's civil war could constitute war crimes or crimes against humanity.

Rape As A Weapon

In conflicts like this, the MSF staff tries to take a stance that's fiercely neutral. To provide medical care in the midst of a war, they need access, they need to appear impartial, and they need to not antagonize gunmen who may decide to ransack their hospital.

So the MSF personnel won't talk about who is raping whom.

They simply care for the women and girls who have been assaulted.

Anissa Dickerson, an American midwife, has been working for the past six months on the maternity ward and on the ward next to it, the tent marked by a yellow flower, the sexual violence ward.

It's Dickerson's second-to-last day before she heads home to Massachusetts.

She is part of a team that built up the sexual violence ward. They offer rape kits with drugs that could protect women from sexually transmitted diseases or unwanted pregnancy. "But we see mostly women who were raped two, three, sometimes six months ago," she says. "We see women who have walked three days to get here trying to get away from violence or leaving their village because there's no food available anymore." They provide counseling and referrals to other support groups in the camp.

On the maternity ward, Dickerson seems to delight in working with the premature babies. Her brown eyes light up and she flashes an impish smile when a former patient shows up at the neonatal intensive care unit. All the woman wants is to get her baby weighed, and she doesn't need to be in the neonatal intensive care unit for that. Dickerson humors her, laughs with her and reassures the young mother that her child is healthy. "We'll get your baby weighed and then maybe send you to pediatrics, OK?" she says.

When Dickerson talks about the sexual violence unit, however, her lightness evaporates.

"We've seen girls as young as 12 and women as old as their late 50s. So it happens — it happens to everyone," she says. "You know pregnant women and breast-feeding women used to be kind of a protected group. It wouldn't happen to them. But it happens to them as well. It's common to hear of women being raped by multiple men. Even pregnant women, you know, in front of children. They're very common stories that we hear over and over."

This is Dickerson's first mission with MSF. She quit her job as a midwife in western Massachusetts to come here because, as she puts it, "I believe that all women should have a safe place to deliver. That's really important to me. And unfortunately, in this country, most women don't. And that's why I want to work here."

But it's been a hard six months. "Hearing these [rape] cases every day — emotionally it's been difficult," she says.

"To some extent I've had to turn some emotion off to make it through this. You know it's hard to hear these stories and feel each one, and I don't think I would make it through six months of this, feeling the emotions of each of these stories. It makes me angry about what's happening. I think that eventually I'll deal with it but I haven't quite yet. It's frustrating. I'm here to do the medical side and we're doing that, but it's frustrating that I — that we — can't provide more than medical and psychological care to these survivors."

She says she's lost a lot of weight over the past six months. "I definitely have plans to eat a lot when I get home — lots of eating. Lots of sleeping."

Down the road, she hopes to sign up for another assignment with MSF, but possibly something different: "Yeah, something maybe outside of a camp would be nice."

To The Kids, He's A Rock Star Doc

Dr. Nav is at the bedside of an extremely thin, elderly woman with a nasty cough.

"How long has she been coughing like this?" Dr. Nav asks his assistant. The woman continues to cough as Dr. Nav examines her.

"Can you ask: Does anyone in her family have TB? Anyone in her house?"

This tent, like all the other wards here, is packed. People are sleeping under some of the beds.

The coughing woman finally says yes, her husband had tuberculosis.

"How long ago was that?" Dr. Nav asks.

The husband died of TB two years ago. Dr. Nav orders the woman to be moved to the "suspect" tuberculosis ward immediately. The hospital has another ward for confirmed TB cases.

TB can be difficult and time-consuming to diagnose. Sputum samples are sent by plane to Kenya. Diagnosis can be delayed not just by backlogs at the lab but by the flight schedule. Once a patient is diagnosed, treatment takes at least six months, sometimes years.

Many TB patients are also suffering from HIV, although Dr. Nav is careful never to say HIV or AIDS on the wards. He calls it "that immune-suppressive disease that we aren't going to mention."

There's a huge social stigma around HIV here; people who have it can become outcasts. The second problem Dr. Nav and his colleagues face is that this field hospital is not intended to be a long-term-care program. So they face a moral quandary. They could start people on powerful anti-AIDS drugs, but there's no mechanism to ensure that the patients can continue to get the drugs once MSF leaves. Someone with HIV who starts on these drugs is supposed to remain on them for life, long after MSF plans to pull out of here.

This is Dr. Nav's second mission with MSF. His first was two years ago in Yemen. The hospital was surrounded by heavy fighting and treated a lot of war casualties. It was so close to the conflict that Dr. Nav and the other foreign staff were eventually evacuated.

"Yemen was very different. It was also a mission with chronic stress but very different chronic stress," he says. "There was gun shooting and tank shooting and missile shooting all day every day, and there were some very close incidents. I came to peace with the idea that, you know, I might not make it out of that mission."

The stress in this hospital in South Sudan, he says, comes from the incredible volume of disease and health problems.

"I've been here long enough that I can often sort of see someone's mortality a couple of steps away," he says. "They might be still talking but I know that they are sick enough that in this context they'll probably continue to get sicker. And there's nothing I can do to stop that. At home that's really rare. That almost never happens."

In the pediatric ward at this field hospital, a 5-year-old girl drifts in and out of a malarial fever. Eventually, she succumbs. On the TB ward, an elderly man withers to the point that he appears to be just a skeleton draped in loose skin. He, too, slips away.

"We deal with a lot of death — a lot of death — much more than we're used to seeing at home by far," says Dr. Nav. "If a child dies at home in the emergency room, it's quite a significant tragedy. You share it with all of your co-workers and with the family, and it's something you really remember and have a lot of support for. Here a child dies almost every day."

Dr. Nav says part of why it's so difficult is that he knows what it's like to work in emergency rooms in Canada. He knows that with the right equipment and the right drugs, he could save a lot of these kids. But here that's not always the case.

"And it's really difficult when that happens time and time again over months — you know sometimes you question what real benefit you're providing to the community. And so yeah, the emotional toll is very high."

Exercise is one thing he tries to do to cope with the stress. He has set up a set of elastic straps in the sandbagged bunker to use as a makeshift workout machine. He sometimes does sit-ups and pushups for exercise, but it's nothing like being able to go for a long bike ride back in Canada.

For security reasons, the medical staff can't just go for a walk outside the compound. "You can definitely feel confined here," Dr. Nav says.

Late at night he binge-watches TV shows and movies he pre-loaded on his laptop. Breaking Bad is one of his favorites.

Dr. Nav at times gets frustrated. But even though some patients don't survive, many do. Kids recover. Parents recover. When an outbreak hits, patients turn to MSF. Outside the hospital, life for the 124,000 people in the camp can be bleak. People are crowded into a barren expanse of dirt and gravel. Women face a constant struggle to collect water and gather food to supplement the U.N. rations. Some residents say they worry about crime and won't let their children out after dark.

So the hospital tries to provide more than just medical relief. In one tent, staffers have set up a loudspeaker playing music in a waiting area. At times it looks like a disco with kids dancing under a green awning.

Among the kids, Dr. Nav is a rock star. They shake his hand. They yell the Nuer greeting, "MAL-LAY!" at him.

"Every time I walk up and down the aisle I'm greeted by 20 kids who want to shake my hand every single day," he says. "I mean there's lots of smiling, happy moments here. And we get to see a lot of people get better. We get to see them come back here happy and healthy and thankful. And so yeah there's a lot of joy in this place, too, for sure."

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