With no vaccination yet available, care is based on treating other illnesses the patient has, nutrition, hygiene and combating the extremely high fever that comes with the virus. The Kenema treatment centre was considered a 5-star facility "because we had piped chlorine".
When the Kiwi nurses arrived the death rate was about 70 per cent, now down to about 55 per cent. The nurses had signed up for three weeks but asked for an extension because "we still had a job to do".
"While we were there we were so heads-down-and-bum-up we missed a lot of the news that the rest of the world was getting. We weren't influenced by fear or misinformation or politics," Ms Collins said.
As the country's main Ebola treatment centre, patients mainly arrived by ambulance, which helped control when cases arrived. At times sick people arrived in the same vehicle in which others lay dead having died on the way, Ms Collins said. The disposal of bodies was one of the most important aspects of fighting the virus and, culturally, one of the hardest.
"There's no dignity in death with this. With Ebola there can be no touch, it is spread in body fluids, yet these are very tactile people, usually very happy, loving people. It is normal for them to kiss their dead, wash and dress them, sit with them . . . None of that can happen now. These people's lives are just being torn apart, but they continue to hope, they wear t-shirts saying 'we can beat this'. They're amazing, wonderful people."
The international team was responsible for every aspect of developing and running the hospital. Closed borders and other interruptions played havoc with supplies. At times, carrying fistfuls of cash, Ms Collins scoured Kenema, 18km away, for gumboots, scrubs and other equipment: "You're never just a nurse."
"Then before we could open we were told, 'right, you've built this hospital, now find people to work there'."
The hurting, determined people did respond to the call, but it meant 150 of them needed "instant training" - in health care, safety, cleaning, cooking, dead body management, and other roles.
"We found a hall, we found a megaphone . . . Never before have I delivered lectures with a megaphone," Ms Collins said.
Time and again she was thanked by people for leaving her family and safe life and coming to their country to help.
"I was humbled to be there, humbled by their gratitude, but they were the true heroes. Those 150 workers were often ostracised, they couldn't even rent places, some were thrown out because their landlords thought they'd bring the disease home."
The Red Cross also developed a triage outside the Kenema Government Hospital to catch patients presenting with Ebola.
"We had a 1.5 metre high wire fence between us and the patients. You could tell straight away if someone had Ebola," Ms Collins said.
"Happy time" for the international workers was contact with home, an hour each night of "hit and miss" wifi, after 14-hour, 7-days a week shifts. ("My poor husband, he got left at home for a month with three teenaged girls.")
Returning home, Ms Collins underwent 21 days quarantine and daily health monitoring - longer than World Health Organisation and Ministry of Health recommendations - before returning to work.
Her resolve to work in international humanitarian aid has strengthened. "Seriously, this is what I've dreamed of working in. I would go back tomorrow. Bring it on."
She holds onto one particularly profound moment, experienced on her first shift, a night shift, working with patients when the new hospital was opened.
"At the end of the shift, a Finnish nurse said 'Donna, look'. I looked over my shoulder and there was the most beautiful sunrise.
"I thought, 'I'm here, we've built a hospital in four weeks, we've trained all these people . . . and it's a new day. We're going to beat this thing'."