"These women are so tough. They walk for days and days. Pregnant and carrying their other children in their arms and then would give birth and pick up the baby and carry on. Who in the world can do that?
"As a Red Cross worker you remain impartial but there were days where I saw such terrible things that I actually got really angry because I realised there was no humanity going on here."
Ms Collins said the mother of an unconscious 11-year-old girl, who had been raped during her journey to the camp, beat her for whatever reason when she woke up.
Babies died in labour, including one with a cleft lip and palate, who lived three days only.
"She had inhaled some of the poo in labour which here would mean a baby would be in special care until her lungs were right and her cleft lip and palate would in future be operated on and fixed but unfortunately it means a death sentence there and she lasted three days."
The first birth she helped with went well but she next dealt with a woman who had birthed in the camp and suffered massive blood loss.
"We gave her two units of red blood cells and the next day her haemoglobin level was seven which is where in New Zealand we'd start transfusing somebody. But they are tiny people and two units of blood and the woman was up and running around in no time. Unbelievable."
She worked on average 14 hours a day and was on call every third night.
"I felt completely disappointed that I was leaving because I had worked four weeks on the trot, no days off, not even down time, time to sleep and that was it.
"And just knowing that I really had my mojo, I was feeling fit and well and I just wanted to continue because there's so much to do," Ms Collins said.
Although more than 1 million people lived in the camp, she said everything from sanitation to medical treatment was well organised.
"Orange and blue tarpaulins and tin roofs as far as the eyes can see and knowing that that is literally two to three families living in each of those dwellings. It's just gobsmacking.
"The whole place is just housing, all accommodation and they even have to cook inside dwellings because there are no outside areas to cook which means most people have got smoke-induced chest infections so everybody seems to appear with this awful wet cough and I think it's mainly from cooking inside the dwellings."
Ms Collins thanked her employer, the Northland District Health Board, and her family for their ongoing support.
Those wishing to donate money to the humanitarian crisis can do so through www.redcross.org.nz/donate/myanmar-refugee-crisis-appeal.
