“She denied ever having been sick with the disease, and it is likely she never knew she had it, suffering only a mild flu-like episode,” writes Judith Walzer Leavitt in her book Typhoid Mary: Captive to the Public’s Health.

Immune to the disease herself, Mallon was the first person in the United States identified as an asymptomatic carrier of the pathogen. (Credit: Fotosearch/Getty Images)Īlthough she harbored the extremely contagious bacteria that cause typhoid fever, Mallon never demonstrated any of its symptoms-which include fever, headaches and diarrhea. Illustration of Typhoid Mary breaking skulls into a skillet, circa 1909. The teenager moved in with her aunt and uncle in New York City, and even as an adult Mallon never lost her lilting brogue. Mallon traveled by herself to start a new life in the United States in 1883. She emigrated from Ireland as a teenager. In 1922, New Yorker Tony Labella, a food worker, reportedly caused two outbreaks that combined for more than 100 cases and five deaths. However, based on the confirmed fatalities, Typhoid Mary was not even the most lethal carrier of the typhoid germ in New York City’s history. Since she used a number of aliases, it’s possible the true death toll could have been higher. Mallon was presumed to have infected 51 people, and three of those illnesses resulted in death.

Only three confirmed deaths were linked to Typhoid Mary. Mallon’s hometown in County Tyrone was among one of Ireland’s poorest areas. She was born on September 23, 1869, in Cookstown, a small village in the north of Ireland. Typhoid Mary's real name was Mary Mallon.

Typhoid Mary by Judith Walzer Leavitt