Who was Typhoid Mary, and what did she actually do?

Typhoid Mary was Mary Mallon, born on September 23, 1869, in Cookstown, County Tyrone, Ireland. She worked as a cook in New York and became the first person in the United States identified as an asymptomatic carrier of Salmonella typhi, the bacterium that causes typhoid fever. She is believed to have infected dozens of people, with three confirmed deaths, and she died on November 11, 1938, on North Brother Island. [1] [2]

Mallon emigrated from Ireland in about 1883 or 1884. In the summer of 1906 she was hired as a cook by a banker who rented a house at Oyster Bay on Long Island. Within weeks, six of the 11 people in the household had typhoid fever. The family hired sanitary engineer George Soper, who ruled out sources such as contaminated water and traced Mallon's employment history, finding typhoid cases wherever she had worked. [3] [4] [5]

Mallon had no symptoms and did not believe she could be spreading disease. When Soper asked for samples, she chased him away. In 1907 health officials took her by force to a hospital, where tests found typhoid bacteria in her body. She was then held at Riverside Hospital on North Brother Island. Doctors said the only cure was removing her gallbladder, which she refused. [4] [5]

Mallon sued for release in 1909 without success. In 1910 a new health commissioner freed her on the condition that she not work as a cook and that she report to the health department regularly. The city offered to help her find other domestic work. [4] [1]

In early 1915 she was found working under the name Mary Brown as a cook at Sloane Maternity Hospital in Manhattan. At least 25 people there were diagnosed with typhoid and two died. She was returned to North Brother Island and remained there until her death. [4] [1]

The sources give different figures. Wikipedia says she is believed to have infected up to 57 people, with three confirmed deaths. National Geographic says at least 51 people caught typhoid through her and that the true number was probably much higher. The Library of Congress guide cites public health experts blaming her for more than 26 serious cases, an older and lower count. Because she used aliases, History.com notes the real death toll could have been higher. It adds that, going by confirmed deaths, she was not the most lethal typhoid carrier in the city's history. [1] [5] [6] [2]

The New York American called her Typhoid Mary in 1909, and the name stuck. It later became a general term for anyone who spreads disease. Wikipedia attributes the nickname to health department officials, while National Geographic credits the newspaper, so the exact origin is described differently. [5] [1]