The case of "Typhoid Mary" would change public health and medicine's understanding of how diseases are spread by asymptomatic patients. For Mary Mallon, some peach ice cream and poor hand washing were the perfect combination to change the lives of an entire family—and entire city—in the summer of 1906. And the sickness didn't stop there.

Soldiers Being Inoculated For Typhoid, World War I

Wordpress/Evidence Bytes

Prior to the 20th century, typhoid was a serious threat to certain populations, in particular those in the military or families living in very close quarters. As scientists learned more about the cause and spread of typhoid, such as contaminated water supplies and contact with an infected person, they were able to limit the spread of the disease. When a vaccine was developed in 1896, the rate of typhoid steadily declined in the United States.

A Victorian Picnic

Wordpress/Breakwater Picnic

By 1900, the incidence of typhoid in the U.S. was very low. So it was surprising when one affluent New York family and their house guests suddenly came down with the illness after a summer picnic in 1906. After they had recovered, the family hired an investigator, George Soper, to track down the cause of the illness, both to clear their name and to prevent any further occurrence.

George Soper, Investigator


Soper was eventually able to track the source of the illness to a cook that the family had hired for the summer, and more specifically, a tub of peach ice cream that she had made for the family. Soper caught up with the cook, 37-year-old Mary Mallon, in the kitchen of her new employer. When he presented his case to her, and told her that he believed she was the source of the typhoid outbreak, she became irate.

Typhoid Notice Of Quarantine, Early 20th Century

Blogspot/Mr. Hall's History

According to Soper's 1907 records, "I had my first talk with Mary in the kitchen of this house. . .I was as diplomatic as possible, but I had to say I suspected her of making people sick and that I wanted specimens of her urine, feces, and blood. It did not take Mary long to react to this suggestion. She seized a carving fork and advanced in my direction. I passed rapidly down the long narrow hall, through the tall iron gate, . . . and so to the sidewalk. I felt rather lucky to escape." Still, Soper was not daunted. His research into Mary Mallon's past illustrated a history of typhoid and other mysterious fevers in many of the houses in which she had worked as cook. He, along with doctors, believed Mallon was the first documented person to be a "healthy carrier" of typhoid.

Mary Mallon's Test Results


When Soper returned to see Mallon again, he brought with him Dr. Sara Baker and five police officers. Still, Mary Mallon would not be easy to apprehend. Dr. Baker states, "Mary was on the lookout and peered out, a long kitchen fork in her hand like a rapier. As she lunged at me with the fork, I stepped back, recoiled on the policeman and so confused matters that, by the time we got through the door, Mary had disappeared. 'Disappear' is too matter-of-fact a word; she had completely vanished."

Dr. Sara Josephine Baker

The team finally caught up with Mary Mallon a few hours later and brought her into the hospital for testing. It was quickly confirmed that her stool samples were teeming with typhoid bacteria. In spite of having no symptoms of typhoid, Mallon was able to infect anyone she came into contact with by handling her own infected stool and then preparing food. Mary, who had never felt ill herself, did not believe the doctors. Nor did she believe in hand-washing. They kept her in the hospital until she agreed to comply with their only stipulation—that she not do any further kitchen work if she was released. She finally agreed to comply.

Mary Strikes Again

Wordpress/Victorian Paris

In 1915, a typhoid outbreak occurred in a New York hospital. Twenty-five people came down with the illness and two people died. The outbreak was traced to the hospital's kitchen and in particular, the shift of a Mrs. Brown. Mrs. Brown was, in fact, Mary Mallon. At this point, Mallon, known to much of New York as Typhoid Mary, was considered a public health threat, having directly infected 51 people, and indirectly, many more.

Typhoid Mary Cartoon, 1915

Wikimedia Commons

Public health officials worked to have Mary Mallon quarantined, for the safety of the city. In late 1915, Mallon was petitioned into the hospital on North Brother Island, New York. While the public was divided over her plight, much of the city was in favor of keeping her in isolation, due to her repeated disregard for the health of others.

Mary Mallon, In Isolation On North Brother Island

New York Daily News

Mary Mallon eventually moved from the hospital to a small cottage on North Brother Island, where she was allowed some luxuries, but never complete freedom. She worked in the hospital lab and had few visitors, with the exception of doctors, nurses, and her lawyers.

Soap Ad, 1910s, 'Because How Many Typhoid Mary's Are There Out There?'

While Mary Mallon was perhaps one of the first confirmed cases of a healthy carrier of typhoid, most experts agree that by the time of her imprisonment there were many other "silent carriers" in the city. Why was Mary Mallon quarantined for the rest of her life, while others walked free? Mary Mallon did not understand this herself. She worked tirelessly on her own behalf to free herself from what she believed to be an "unfair imprisonment."

Mary Mallon's Cottage On North Brother Island

Washington Post

After over 20 years on North Brother Island, Mary Mallon died in her small, quarantined cottage in 1938. Her case increased the awareness in the medical community about the concept of healthy "carriers" of disease and also brought up issues about the legality of quarantining against a patient's will. The legend of the unknowing person, who quietly infects others with a deadly disease, is now colloquially known as a "Typhoid Mary." And Typhoid Mary's story is one that's difficult to forget.