With his unique techniques, Zhu usually has hundreds of patients waiting outside his office on a typical afternoon. But the workload is dwarfed by what he has experienced in Africa.

On a typical day in Africa, Zhu had to see more than 300 cases, which means he had to perform one operation within three minutes. Zhu said his cervical problems worsened due to the heavy workload.

But the overwhelming gratitude and infectious delight from his patients has carried him on. "An African patient who lost his vision for more than 20 years was astonished when he regained his sight after a mere three-minute operation. He was not convinced until he physically checked each and every hand in the room.

"His first sight was also astonishing as he saw only Chinese faces. He ended up saying that in 20 years all of us seem to have got yellow skin.'"

Zhu said his fame preceded him everywhere in Africa that not even golf courses would allow him to tip. They often called me the magical Chinese doctor, he said.

"I can really feel the sincerity of their (African people) wishes. This is what connections between nations are. As a doctor, we cure people regardless of race and nation. Our calling comes knocking as soon as we see people who are suffering from sickness. Their support adds to our sense of responsibility," Zhu said.

Zhu also praised the dedication of his co-workers and volunteers from Hainan Airlines, who helped organize and guide the hundreds of patients every day despite fatigue and illness.

"Many become sick after landing in Africa, but they kept on working. Without them, I could never have made it. As long as they carry on, I have no excuse to pause. In the end I was the one who was earning all the credits, but they are the real unsung heroes."

The three trips to Africa have left Zhu with refreshed impressions of the continent.

"They are so eager to learn that they stand all day long, watching and asking."

The respect the African patients show to doctors is also something that Zhu found impressive. When one patient failed to get in after waiting for a whole day, he came to Zhu and bowed and said: "Thank you doctor Zhu, you had a very hard day. I will come back tomorrow."

"That was something I haven't heard for a long time. The friendliness was mutual. In China, a patient could get really upset instead of considering the doctor's workload."

Zhu is now preparing for his next trip to Africa, recruiting new members for the medical team. He has to pin down the strength to 10 from the over 50 candidates. "We want the best. With a workload like that, you have to be very careful. In China, the patients might still have chances for patch ups. In Africa, this is their only chance. There is no room for failure."