Mathilde Krim, who crusaded against the scourge of AIDS with appeals to conscience that raised funds and international awareness of a disease that has killed more than 39 million people worldwide, died on Monday at her home in Kings Point, N.Y. She was 91. Her death was confirmed by Bennah Serfaty, a spokeswoman for amfAR, the Foundation for AIDS Research, of which Dr. Krim was the founding chairwoman. When the nation learned in the early 1980s that the virus that causes AIDS had begun its terrifying attack upon the human immune system, Dr. Krim, a geneticist and virologist with wide experience in cancer research and a passion for causes, plunged into a fight not only against the virus but also for the civil rights of people who had it. Her husband was the entertainment lawyer Arthur B. Krim, a former chairman of United Artists and Orion Pictures and of the Democratic National Finance Committee. He was a confidant of many national leaders, including Presidents John F. Kennedy, Lyndon B. Johnson and Jimmy Carter. She was born Mathilde Galland in Como, Italy, on July 9, 1926, to Eugene Galland, a Swiss-Italian, and the former Elizabeth Krause, an Austrian. Her father was an agronomist. The family moved to Geneva when Mathilde was 6. At the University of Geneva, Mathilde was a brilliant student of biology and genetics. After earning a bachelor’s degree in 1948, she married an Irgun comrade, David Danon, a Bulgarian medical student, and converted to Judaism. The couple had a daughter, Daphna, in 1951, and in 1953, after Mathilde received her doctorate, they emigrated to Israel, where the marriage ended in divorce. In 1954, she joined the research team of the German-born Israeli molecular biologist Leo Sachs at the Weizmann Institute of Science in Rehovot. She married Mr. Krim, a Weizmann trustee, in 1958 and moved to New York the next year, exchanging pioneer life in a perpetual war zone for the Upper East Side and an illustrious social milieu. Dr. Krim resumed research — at Cornell Medical College from 1959 to 1962 and at Sloan Kettering from 1962 to 1985. She was later an adjunct professor at Columbia University. Dr. Krim is survived by her daughter, Daphna Krim; two grandchildren; and a sister, Maria Jonzier. Arthur Krim died in 1994.