"Now, we have built roads, bought cars and built houses. Women of our village can get married to outsiders, and outsiders would like to live in our village. Children of our village are admitted to school in the town like their counterparts from other villages," says Ai.

"We owe all of this to Li. She cured our disease, and enabled us to live like normal people," he adds.

Li continued to do research on the effect of MDT, and expanded the pilot areas to 59 counties in seven provinces. Her statistics show that the patients, after receiving MDT, have a minuscule recurrence rate of 0.03 percent, much lower than the 1 percent standard the WHO set to identify the effectiveness of the therapy.

"Before the 1980s, leprosy patients only took one medicine for four to six years, but they often relapsed. MDT met many objections at the beginning, so Li took a risk trying it. But it has proved effective, greatly speeding up China's process of wiping out leprosy," Yuan Lianchao, an assistant of Li, and also secretary general of China Leprosy Association, tells China Daily.

Behind the achievements are unknown difficulties. Since many villages Li visited are located in the deep mountains with difficult roads, she was injured in several traffic accidents. "Once when she was nearly 70, she was thrown out of the car from the window, resulting in broken ribs and collarbones, and a head injury. But she just said, 'Since I take a car so frequently, it's about time I had an accident.' When the boat she took to a village capsized, she joked to those who saved her, 'Don't worry, I am as fat as a rubber ball so I will not sink'," says Yuan.

With the efforts of Li and other researchers, China has less than 2,000 leprosy patients now compared with more than 500,000 patients when New China was founded in 1949. The incidence rates in more than 98 percent of Chinese counties are lower than 1 in 100,000, according to Yuan.

She never married. "In this way, I can devote myself to the work without worrying about family issues. I believe you should not calculate the price you have paid for the cause you are determined to engage with, or you cannot make much progress. Curing the patients is the happiest thing in my life," says Li.