In this book, historian Judith Walzer Leavitt tells the remarkable story of Mary Mallon, the woman known as "Typhoid Mary." Combining social history with biography, Leavitt brings to life early-twentieth-century New York City, a world of strict class divisions and prejudice against immigrants and women. She re-creates the excitement of the early days of microbiology and explores the conflicting perspectives of journalists, public health officials, the law, and Mary Mallon herself.

Mary Mallon was the first healthy carrier of typhoid to be carefully traced in North America, but there were other healthy carriers - over 400 in New York City alone by the 1930s - whose treatment was much less harsh. Why did Mallon's case turn out as it did? As Leavitt shows, the answers have to do with popular prejudices as well as with the legal dimensions of Mallon's case.

By exploring the many contexts for Mallon's experience, Leavitt provides a rich and many-layered chronicle of a woman's personal tragedy and a society's dilemma. She also explores the continuing cultural significance of Typhoid Mary, describing the ways Mallon's story has been reinterpreted in fiction, drama, and historians' narratives up to the present.