A United States surgeon and missionary has for more than a decade been working in the Nuba Mountains in the border area between Sudan and South Sudan in a bid to help save the lives of civil war victims.

Tom Catena, 54, has helped tens of thousands of local residents caught in the crossfire of the Third Sudanese Civil War which followed the declaration of South Sudan's independence on July 9, 2011.

The Nuba Mountain region, which is directly on Sudan's side of the border between Sudan and South Sudan, has been a point of conflict between the Sudanese military and rebel groups, many of whom want the mountainous enclave to break off from Khartoum and join Juba, the capital of South Sudan.

"Before the war, we treated common diseases: malaria, tuberculosis, people with leprosy, cases of diarrhea, polio (infantile paralysis) and cancerous tumors," Catena told EFE.

"But since the conflict started, we have had an endless number of new cases," he added.

Catena arrived in the Nuba Mountains in 2007 as a Catholic missionary and in 2013 helped establish the Mother of Mercy Hospital in the mountain town of Gidel.

Tens of thousands of local Nuba people have traveled for days by foot or hitchhiked in order to be seen by Catena as Mother of Mercy Hospital is reportedly one of the only hospitals open in the Nuba Mountains.

When EFE journalists visited Mother of Mercy Hospital, the hospital had 400 beds, many of which were filled with soldiers injured by shrapnel as well as civilians with much of their bodies burned.

The 2017 Aurora Prize for Awakening Humanity awardee Catena said that he never thought about quitting his work even in his hardest days: "From the outside, when you look at places like the Nuba Mountains, you think your effort is useless. A drop in the ocean.

"But it is all about perspective. When you get to know the people here, you understand that their life is of enormous value. Same as anyone's life is. And you see them as you would see someone in your family or someone from your own town," he explained.

Catena is reportedly on call 24 hours a day seven days a week and performs thousands of different operations per year; yet, he dreams of revamping his hospital and bringing in a new generation of doctors from the Nuba Mountains.

"The goal is specialize in different fields: one in surgery, another in pediatrics... And then I can take a step back. I do not want to turn 70 and continue to operate while Nuba youth watch me," Catena stated.

The Nuba Mountains are named after the indigenous people, yet "Nuba," as a term, is a complex name as it has been given to peoples of various ethnic and linguistic backgrounds all of whom live in the Nuba Mountains of South Kordofan, a province of Sudan.