She was born in County Tyrone, Ireland, in 1869. She emigrated to the United States in 1884 at the age of 15. She died in New York City in 1938 at the age of 69. You never would have heard of Mary Mallon if not for George Soper.
Every discovery is two stories: the discovery itself and how it was made.
How the discovery was made
From 1900 to 1907, Mallon worked as a cook in eight wealthy households. The seventh was an Oyster Bay property occupied by Chares Henry Warren, a banker. Warren rented the house in the summer of 1906. He took along his family; his cook, Mallon; and other staff. During their sojourn, six of the 11 in the household contracted typhoid fever.
When the Warren family left Oyster Bay, the owner of the property realized no one would rent his property again if it had the reputation of containing typhoid. Enter George Soper. The owner, as a plain matter of business, contacted Soper, a sanitary engineer, to discover how the renters contracted typhoid and certify the house itself blameless. Soper held a doctorate from Columbia University and was managing director of the Research Laboratories of the Public Health Department of New York City.
At that time, typhoid was more often an affliction of the poor in urban areas. It was rare in Oyster Bay and rarer still among the haut monde. Soper can be forgiven for first blaming bad clams. He corrected course after interviewing staff and householders, including Mallon.
He made his monumental discovery when he realized Mallon had encountered typhoid in all of the prior households in which she worked. Soper was already interested in the cause of typhoid among those wealthy households. Now he had the common thread: Mary.
The discovery
Mary Mallon was something almost unheard of in the early 20th century: an asymptomatic carrier of typhoid. In fact, she was the first known asymptomatic carrier. Soper discovered she was spreading the disease. From June 15, 1907, when Soper published his findings in the Journal of the American Medical Association, Mary Mallon was labeled “Typhoid Mary.” In the seven years, 1900 to 1907, she infected at least 53 people.
The fate of Typhoid Mary
Once the article was published, the next step was to find and isolate Mallon to stop the spread of disease. It was not easy. Mallon served in eight households in seven years, always leaving immediately after outbreaks. She never left a forwarding address. She did not always use the same name. She was described as an Irish woman, about 40 years old, tall, heavy-set, and in perfect health. The description was not much help.
Typhoid Mary was tracked down and arrested by Ms. Willa Carey Noble, a bacteriologist in Soper’s office. Walter Bowen reported a case of typhoid in his Park Avenue residence. His maid fell ill in January 1907. When another servant fell ill, both were hospitalized. Then it was Bowen’s daughter; tragically, she died. Noble discovered that Mallon was the cook in the Bowen household.
Soper met Mallon in the Bowen kitchen. He accused her of spreading the disease. Soper reported he was diplomatic, but it is unclear how you diplomatically accuse someone of inadvertently infecting and killing people. Mallon did not believe him and threatened Soper with a carving fork. He fled.
Noble discovered where Mallon lived. Soper and a doctor visited and attempted to convince Mallon to quarantine voluntarily. She believed typhoid was “everywhere” and some people just “picked it up.” She had never heard of an asymptomatic carrier (nor had any one else) and did not believe she was one. She believed a person was either sick or not sick. She was not sick and, therefore, would not agree to quarantine.
Mallon was forcibly quarantined as a public-health threat. Five policemen forced her into an ambulance, and one sat on her to quiet her. In captivity, samples were taken, and typhoid was discovered. During interviews, doctors discovered Mallon almost never washed her hands.
Forcible quarantine raised ethical issues, as did her treatment in custody. Mallon suffered from a nervous breakdown. In 1909, she tried to sue the New York Health Department, but her complaint was denied. After three years, Mallon was released upon conditions that she would not work as a cook and would practice reasonable hygiene.
She began work as a laundress. However, a cook was paid $30 more per month—a fortune to Mallon. The lure of the money was irresistible. She changed her name and took a job as a cook. To avoid recapture, she changed names and jobs frequently. At no time in her life did she believe she carried typhoid or infected others. Soper could not find her.
In 1915, while working at Sloane Hospital for Women, Mallon infected 25 people, two of whom died. The head obstetrician, Dr. Edward B. Cragin, asked Soper for help coping with the outbreak. Soper immediately identified Mallon. That year she was returned to quarantine, where she remained for 23 years until her death in 1938.
