Like every other volunteer who serves with Medecins Sans Frontieres, Stefan Liljegren joined to help the sick and destitute.
In 15 years with the agency, he has been everywhere from Afghanistan and Kosovo through to South Sudan and East Timor, the hard and often dangerous work compensated for by the knowledge that he is saving lives.
As field co-ordinator of MSF's new 160-bed Ebola treatment centre in Monrovia, the capital of Liberia, he decides which of the sick people who arrive outside the clinic's gates should get treatment.
For every 20 to 30 new patients admitted each day, the same number are often turned away.
"This is by far the most difficult challenge that I have ever faced," the 44-year-old Swede said. "Every day I have been faced with impossible choices, and decisions that are inhuman to make. Having to tell someone they can't come in when they are screaming and begging to do so is an indescribable feeling, especially when you know they may go back to families who might well then get sick themselves."
Outside the clinic an hour earlier, a grisly scene demonstrated Liljegren's point. Resting face down in the mud, an arm crooked over his face, was the body of Dauda Konneh, 42. He had been lying there dead since daybreak.
The hospital does not admit anyone at night, handling Ebola patients requires extreme care at the best of times, and it would be dangerous to do so in the dark.
The task of removing Konneh's body falls to Stephen Rowden, an MSF volunteer from Danbury, Essex, who leads a team in charge of the safe removal of corpses.
"When I started it was maybe a body every two days, now it is daily and sometimes up to five a day," said Rowden, 55. "I have never seen this amount of bodies before."
The clinic, one of three in Monrovia, has seen 350 deaths in the past month alone. Since all infected bodies have to be burned, the casualties have exceeded the capacity of Monrovia's crematorium.
MSF has had to import an incinerator from Europe - normally used for livestock.
The challenges facing the MSF clinic are a snapshot of the wider outbreak engulfing West Africa. This week a World Health Organisation study warned that the number of Ebola cases, currently topping 5000, could reach hundreds of thousands by January unless the aid operation was drastically increased.
In Liberia, 40 per cent of the deaths have taken place, and the government health service has been paralysed by Ebola infections among its own staff. In coming weeks, a 3000-strong US military mission will arrive in Monrovia to build 17 more Ebola treatment clinics.
There is no telling how many more desperate people may soon be pleading at the clinic's gates. "It gets worse by the day," Liljegren said. Telegraph Group Ltd