ROANOKE, Va. (AP) — Those who know 18-year-old Anderson Mambwe say in the past several months he's transformed.

The soft-spoken, lanky and now tall teenager from Zambia came to the United States in March for surgery on his feet, which are deformed because of a congenital birth defect that went unchecked in Africa.

For years Anderson has suffered excruciating pain just to walk on his large, misshapen feet. The only treatment in Zambia was amputation. He was meek and small — until now.

"He was passive. He was quiet. He was scared," said local podiatrist Charles Zelen, who is helping treat Anderson. "And now he's revealing self-confidence and respect for himself. Rather than being so fearful and scared, his personality is coming out. His enthusiasm is now coming out. He's now proud."

Zelen performed the first of two surgeries to repair Anderson's feet in April, and the procedure hasn't just changed his walk, but his personality.

Since his arrival in Roanoke, Anderson has also shot up, growing about 6 inches and gaining approximately 30 pounds. Zelen said the teen was malnourished in Africa and his growth plates were open, so once he came here and began eating three meals a day he grew.

The teen, who months ago may have shied away from conversation, now talks excitedly, albeit still softly, about his future. After he returns to Zambia in November, he hopes to finish school and then become a lawyer.

It's a future that's wide open to him now, said Roanoke nurse Karen ReMine, who is co-founder of Roanoke County-based Orphan Medical Network International, which fostered Anderson's medical visa.

"His personality has changed because he was dealing with his feet," ReMine said. "It's a total difference from someone who would stay secluded in his room."

ReMine's group rarely brings children inside the country for a medical procedure. In fact, it's only been done one other time and that was for ReMine's now adopted son, who is also from Zambia and needed a club-foot correction.

Her organization learned about Anderson from Seeds of Hope, an organization that offers aid to people in Niger, in west Africa. She approached Zelen, who donated his services. LewisGale Medical Center is contributing more than $100,000 in charity care.

ReMine said Anderson just needed someone to advocate for him. She was spurred to action when she found out he could lose his legs.

"It can't happen to a boy that bright and deserving of a chance at life," she said. "That's all you need is a chance."

ReMine and Zelen said Anderson's story is one that's important to bridging relations between Zambia and the U.S. ReMine said in Anderson's own country his story is becoming well known. She said the ministry of health and the former first lady know about his story,

"It's just for me exciting many people know about me," Anderson said, adding he looks forward to returning to school.

Just attending classes posed a problem for him before because sometimes he was in too much pain to attend at all or was in discomfort.

"I think it will be more easier for me to study hard," he said. "I wasn't able to move in class."

But before he can return home, Anderson will have a second surgery, on Aug. 31, to correct his right foot. He said he's not nervous and is "looking forward to it."

The first surgery to repair his left foot took six hours and required 15 cuts into bone. Surgeons used 20 metal implants to shorten and straighten the bones that were so deformed Anderson could barely walk on them.

His feet are so large that the screws surgeons typically reserve for ankle fractures were used to fuse his toes. Zelen said the largest implant available for toes, typically used for a big toe, was only able to fit into Anderson's fifth toe.

His feet before surgery were a size 17 in length and EEEEE in width. Afterward, both will be about size 13.

Anderson spent four nights in the hospital recovering, and his foot was in a cotton splint for two weeks. After that he wore a cast for six weeks.

But on a recent day, most signs of that onerous recovery were gone.

Standing in an exam room just after a shoe fitting, Anderson looked the part of a typical teenager. He smiled, talked about his favorite American foods (cheeseburgers and fries) and his newfound affection for bike riding. He wore jeans, a button down black shirt and shoes, which for many years was unfathomable.

His black lace-up sneakers, Nike on the left and New Balance on the right, exude cool. Once surgery is completed on his other foot, he'll don matching shoes. Nikes.

How does he feel?

"First it felt so strange, now it's feeling good."