Mary Mallon, commonly known as Typhoid Mary, was the first documented healthy carrier of the disease typhoid fever in the United States. Her case became widely known after she was identified as the source of multiple typhoid outbreaks in New York City between 1900 and 1907, leading to significant public health concerns. Despite showing no symptoms herself, Mallon's cooking skills inadvertently spread the disease to others, infecting numerous individuals, some of whom died from the illness. As a result, health officials were compelled to act to protect public health, ultimately quarantining her in 1907. After her initial release, Mallon continued to work as a cook, leading to a resurgence of infections, which prompted her second quarantine in 1915.

During her second confinement, Mallon was placed on North Brother Island in the East River, a site designated for isolating contagious patients. This confinement was a significant episode in public health history, reflecting the tensions between individual liberties and community health. Mary Mallon's situation posed complex ethical questions about personal freedoms, particularly when public safety was at stake. Despite multiple offers to assist her in gaining independence from quarantine, Mallon remained resistant, insisting she had done nothing wrong. Her situation captured public attention, illustrating the struggles of those labeled as carriers of infectious diseases and highlighting the need for improved food safety practices and health regulations.

Mallon lived the remainder of her life in isolation until her death in 1938. Over the years, her case generated debates concerning health rights, individual liberties, and the measures required to combat the spread of infectious diseases. It also set a precedent for how health authorities approached carriers of contagious diseases and their responsibility to the public’s health.