Typhoid Mary's Second Quarantine (1915)

March 27, 1915

On March 27, 1915, New York City health authorities forcibly returned Mary Mallon to isolation on North Brother Island, where she would spend the rest of her life. Known to history as 'Typhoid Mary,' Mallon was the first person identified in the United States as a healthy carrier of Salmonella Typhi, the bacteria that causes typhoid fever, and her case reshaped how public health officials balanced individual liberty against the protection of public health.

An Unlikely Suspect

Mary Mallon was born on September 23, 1869, in Cookstown, County Tyrone, Ireland, and emigrated to the United States around 1883 at roughly age 15. She built a career as a cook for wealthy families in and around New York City, a job that unknowingly turned her into a walking epidemic. In the summer of 1906, a typhoid outbreak struck the household of banker Charles Henry Warren, who had rented a summer home in Oyster Bay, Long Island, where Mallon worked as cook. Sanitary engineer George Soper was hired to investigate and traced a pattern: over the previous decade, Mallon had cooked for eight families, seven of which suffered typhoid outbreaks shortly after her arrival. Mallon herself showed no symptoms, but stool samples eventually confirmed she carried and shed live typhoid bacteria, likely harbored in her gallbladder. She adamantly refused to believe she was responsible, since she had never been sick herself, and she resisted testing and cooperation at every turn, viewing the accusations as an assault on her livelihood and reputation.

First Quarantine and a Broken Promise

In March 1907, New York City health officials, including Dr. Sara Josephine Baker, physically restrained Mallon and took her into custody. She was confined to an isolation cottage at Riverside Hospital on North Brother Island in the East River, becoming what newspapers soon dubbed 'Typhoid Mary.' She remained there for nearly three years while health officials studied her case, one of the first documented instances of a healthy human carrier spreading infectious disease. In 1910, a new health commissioner released her under the condition that she never again work as a cook and that she report periodically to health authorities. Mallon initially took jobs as a laundress, but the pay was far lower than cooking, and she found the work unsatisfying. Frustrated and convinced she posed no real danger, she abandoned her promise, changed her name to 'Mary Brown,' and quietly returned to cooking under various aliases, moving between households, restaurants, and institutions across the New York area, evading the health department's oversight for roughly five years.

Return to North Brother Island

Mallon's second chapter as a fugitive cook ended in disaster in 1915, when she took a position preparing food at Sloane Maternity Hospital in Manhattan under her alias. An outbreak of typhoid soon swept through the hospital staff, infecting 25 people and killing two. Investigators recognized her distinctive cooking style and confirmed her identity, exposing the alias and her broken promise. On March 27, 1915, health officials arrested Mallon and returned her to North Brother Island, this time permanently. She would remain quarantined there for the rest of her life, spending 23 more years in isolation, working eventually as a technician in the island's laboratory. Mallon died on November 11, 1938, at age 69, after suffering a stroke; an autopsy found live typhoid bacteria still present in her gallbladder. She is believed to have infected as many as 57 people over her career, with three confirmed deaths directly attributed to her, though some historians suspect the true toll was higher. Her case remains a foundational reference in public health law regarding quarantine and individual rights.