Dr. Ruth Pfau visits the flood-affected village of Begna in southern Pakistan's Jati town in 2010. (Asif Hassan/AFP/Getty Images)

Dr. Ruth Pfau, a German nun who became known as the “Mother Teresa of Pakistan” for her decades-long ministry to the country’s leprosy patients, a moral and medical campaign that helped curb one of the most stigmatized diseases in human history, died Aug. 10 in Karachi. She was 87.

A spokeswoman, Salwa Zainab, confirmed her death to the Associated Press. The cause was not immediately available.

Dr. Pfau, while not widely covered in the Western media, was renowned in Pakistan for her efforts to stop the spread of leprosy, a bacterial infection also called Hansen’s disease that when untreated can cause disfigurement and blindness. Around the world, its victims have often been relegated to “leper colonies” and regarded as outcasts.

The Express Tribune of Pakistan once credited Dr. Pfau with having “single-handedly . . . turned the tide of leprosy in Pakistan and won the gratitude and personal attentions of people ranging from military rulers to elected ministers to the general public.”

Like Mother Teresa, the ethnic Albanian nun who became known as “the saint of the gutters” for her service to the destitute of India, Dr. Pfau lived among the people she cared for and by a vow of poverty.

As a young physician and nun, she had planned to begin her missionary work not in Pakistan, but in India, in 1960. Waylaid in Karachi with visa difficulties, she visited a leprosy colony and was so distressed by what she saw that she could not bring herself to leave.

The facility was overrun by rats and soiled by sewage. Speaking to the BBC in 2010, she recalled watching a young man as he “crawled on hands and feet into this dispensary, acting as if this was quite normal, as if someone has to crawl there through that slime and dirt on hands and feet, like a dog.”

“I could not believe that humans could live in such conditions,” she told the Express Tribune in 2014. “That one visit, the sights I saw during it, made me make a key life decision.”

Under Dr. Pfau’s leadership, that facility became the Marie Adelaide Leprosy Centre, the nerve center of a national network of medical professionals who sought to house, treat and, at times, rescue victims of the disease. Dr. Pfau recalled collecting children who had been stowed away in caves or in cattle pens because of their illness.

With support from German donors, Dr. Pfau and her colleagues managed to bring leprosy largely into submission. Since 1996, the World Health Organization has considered the disease controlled in Pakistan. Her organization later worked on the treatment and prevention of tuberculosis and blindness, as well as serving victims of drought, earthquakes, floods and other natural disasters.

Ruth Katharina Martha Pfau was born Sept. 9, 1929, in Leipzig, where her family’s home was destroyed in the bombings of World War II. “If I give any sense to these years, it is a preparation to be ready to help others,” she told the BBC.

After the war, with Leipzig under Soviet occupation, Dr. Pfau fled from East to West Germany to pursue her medical training, according to her biography on the website of the Marie Adelaide Leprosy Centre. She said she nearly married a fellow student before experiencing what she described as a calling from God.

“When you receive such a calling, you cannot turn it down, for it is not you who has made the choice,” she told the Express Tribune. “God has chosen you for Himself.”

She studied medicine at universities in Mainz and Marburg before joining the Catholic order of the Daughters of the Heart of Mary, the organization that sent her abroad as a missionary.

No information on her survivors was immediately available.

For a period, Dr. Pfau served as an adviser to the Pakistani health minister.

“We are like a Pakistani marriage, ” she remarked. “It was an arranged marriage because it was necessary. We always and only fought with each other. But we never could go in for divorce because we had too many children.