Dr. Zena Stein, a South African-born epidemiologist whose influential work encompassed the effects of famine on children, the health of entire communities afflicted by poverty, and the impact of the AIDS crisis on women in Africa, died on Nov. 7 at her home in Coatesville, PA. She was 99.

Dr. Stein’s research focused closely on Women’s health at a time when the bulk of scientific study spotlighted men. She was also well known for her research on child development and on mental illness. She and her husband, Dr. Mervyn Susser, worked as a team and conducted hundreds of studies, many of which shaped the field of epidemiology and community health care. Dr. Stein is listed as the author or co-author of 270 academic articles and several books.

Dr. Stein later turned her attention to the effects of the H.I.V/AIDS crisis on women, who made up a minority of patients and were often overlooked. In 1987, she co-founded the H.I.V. Center for Clinical and Behavioral Studies at the New York State Psychiatric Institute and Columbia University. The center embarked on the first major effort to draw attention to women living with AIDS. It is now one of the largest centers of its kind in the world.