Typhoid Mary, was the first person in the United States identified as an asymptomatic carrier of the pathogen associated with typhoid fever. (She harbored the extremely contagious bacteria that cause typhoid fever, Mallon never demonstrated any of its symptoms—which include fever, headaches and diarrhea).

Attachment 152652. Mary in quarantine.

Although she knew she was a carrier of typhoid, Mary Mallon worked as a cook in and around New York City.

That's how she spread the disease to more than 20 people, before she was caught and institutionalized in 1907.

When she was released, she went right back to cooking — and infecting people. After another typhoid outbreak was traced to her, "Typhoid Mary" was quarantined on an island in the East River for the rest of her life.

Mary Mallon was born in 1869 in Cookstown, County Tyrone, in what is now Northern Ireland. She emigrated to the United States in 1883 or 1884.

She lived with her aunt and uncle for a time and later found work as a cook for affluent families.

Six members of wealthy banker Charles Warren’s household contracted typhoid fever while vacationing in Long Island’s Oyster Bay in the summer of 1906, Typhoid fever was viewed as a disease of the crowded slums, associated with poverty and the lack of basic sanitation.

Concerned that the outbreak would prevent him from leasing out his summer house again, Warren’s landlord hired George Soper, a freelance sanitary engineer who had investigated other sources of typhoid fever outbreaks, to determine the cause.

Although everything from the house’s plumbing to the local shellfish supply came up negative, the dogged Soper found the cause—Mallon, the cook who had worked for the Warrens weeks before the outbreak. Soper researched Mallon’s employment history and found that seven families for whom she had cooked since 1900 had reported cases of typhoid fever, which had resulted in the infection of 22 people and the death of one girl.

Based on Soper’s sleuthing, the New York City Health Department took Mallon into custody in 1907 and placed her into forced confinement inside a bungalow on 16-acre North Brother Island, off the Bronx shoreline, with only a fox terrier as a companion.

In 1910, new health commissioner Ernst Lederle agreed to release Mallon if she pledged never to work as a cook again.

Attachment 152653. This illustration of Typhoid Mary, breaking skulls into a skillet, appeared in a 1909 issue of The New York American.

The health department had lost track of Mallon after her release, during which time she cooked in hotels, restaurants and institutions. After her capture, Mallon was once again confined to North Brother Island.

Six years before her death, she was paralyzed by a stroke. On November 11, 1938, she died of pneumonia at age 69. An autopsy found evidence of live typhoid bacteria in her gallbladder. Mallon's body was cremated, and her ashes were buried at Saint Raymond's Cemetery in the Bronx.