Katherine Hsu pioneered tuberculosis-prevention strategies now replicated around the world.

Born in 1914 in Fuzhou, South China, Hsu counts herself fortunate for having been raised in a Christian home.

From an early age, Hsu wanted to become a doctor. Growing up, she saw the devastating effects of diseases such as typhoid and diphtheria. Then tuberculosis took the life of a younger brother and sister. Believing that being a doctor was "a great purpose for living," she prayed that God would provide a way, promising to make the practice a ministry without charge to her patients.

Soon after that prayer, Hsu won a full scholarship to Peking Union Medical College, one of three applicants accepted. The more she studied the human body, the more she marveled at God's creation and worshipped him. Because her siblings died from tuberculosis, Hsu made the disease her primary focus.

"I had a drive to conquer it and find a solution that would save others from suffering," Hsu says.

Hsu joined the staff at the Pennsylvania Tuberculosis Hospital for Children, where she first witnessed the use of isoniazid to kill TB germs. Immediately, Hsu says, God gave her an idea: Why not use this drug to prevent children from getting sick? The hospital had no outlet for Hsu to test her concept, so once again the doctor prayed. A year later she received a letter from a place she had never heard of-—Houston, Texas.

Houston was in trouble. Tuberculosis outbreaks were rampant. The Baylor College of Medicine's chief of pediatrics invited Hsu to initiate a TB control program for the city's children. First, Hsu needed a clinic.

For the next six years, Hsu converted a dilapidated boarding school into a children's TB clinic where she began treating patients. Soon after, a local millionaire funded a transformation of the clinic into a modern hospital.

Hsu remembered her childhood promise to God to make her practice a ministry. She provided a home-like atmosphere for the patients, trying to model Christ's compassion. Winning her patient's trust, Hsu was able to conduct the longest TB-prevention study in history. For 30 years, she tracked the progress of more than 3,000 children, proving that isoniazid could be used to prevent TB-infected patients from becoming sick.

Six years after founding the clinic, Hsu created Houston's tuberculosis-control program, initiated a case registry still used today, and founded six new clinics in at-risk areas. Since opening, the clinic has maintained an unprecedented 75 to 80 percent patient recovery rate.

"This is not my own achievement, but what God has wrought by his mighty power," Hsu wrote in 1994 after receiving the coveted Distinguished Achievement Award from the 11000-member American Thoracic Society.

True to her word to God, Hsu has not charged a patient in more than 50 years. In addition, Hsu has used all of her medical awards to fund scholarships for students and missionaries.

"What you cannot do, God will work out for you," Hsu says. "Then you become an instrument in God's will. That is a great privilege."