Listening to a recent news report on the quarantine and eventual death of Thomas Eric Duncan, who died last week from ebola in Dallas, the aspect of the story that struck me most was how a single individual stands at the center of a circle of contacts—and possible contagion—many of whom never knew the infected individual.

The idea of a single carrier and contagion made me think of Mary Mallon, the first known “healthy carrier” of typhoid. You known her by the nickname Typhoid Mary.

Typhoid Mary was an Irish immigrant who arrived in the United States in 1884 at the age of 15. She had never had typhoid and as far as she or anyone else knew she was healthy. Like many Irish immigrants at the time, she went into domestic service, where she quickly discovered she had talent as a cook—a prized position because it was more highly paid than most domestic work. She moved from job to job—not unusual for a domestic worker at the time. What was unusual was that typhoid outbreaks followed Mallon from job to job.

Mallon was first identified as a possible carrier in 1907. New York banker Charles Henry Warren rented a Long Island summer home for his family and hired Mallon as a cook for the season. In late August, one the Warren daughters came down with typhoid fever. She was the first: eventually six of the eleven people in the house became ill. Mary Mallon was not among them.

Typhoid was known to be spread by contaminated water or food. The owners of the home were afraid that they would not be able to find more tenants unless they identified the source of the contagion. They hired George Soper, a civil engineer with experience in tracing the source of typhoid fever outbreaks. As part of his investigations, he traced Mallon’s employment history and found that between 1900 and 1907, she had worked at seven jobs at which 22 people came down with typhoid.

Soper didn’t think this was a coincidence, but he needed stool and blood samples from Mallon to prove she was the carrier.

Mallon was once again working as a cook in a private residence. When Soper approached her, she threatened him with a carving fork. After a second attempt, Soper turned his data over to the New York City Health Department. Mallon again refused to cooperate, and responded with violence, profanity and the carving fork that appears to have been her weapon of choice. It took the Health Department doctor and five police officers to capture Mallon* and take her by ambulance to a hospital, where specimens were taken and examined.** Having confirmed that Mallon carried typhoid bacilli, the health department transferred her to an isolated cottage on North Brother Island, where they tested her stool samples regularly for typhoid.

Mallon was held against her will and without a trial. She had broken no laws, and did not understand how she could be a carrier of a disease for which she showed no symptoms. She sued the health department, with no effect. The judge agreed that she should be confined for the public good.

In 1910, a new health commissioner decided Mallon could go free as long as she never worked as a cook again. Not surprisingly, she agreed to the conditions if that’s what it took to gain her freedom.

Five years later, typhoid fever broke out in the Sloane Maternity Hospital in Manhattan. Twenty-five people became ill; two of them died. Evidence pointed to a recently hired cook as the source of the infection: Mallon working under the assumed name of Mrs. Brown. She was sent back to her isolated cottage, where she remained imprisoned for 23 years.

Mallon was not the only healthy carrier identified in New York in this period. She wasn’t the only healthy carrier to ignore health department restrictions after learning she was contagious. She wasn’t even the most deadly. But she was the only one isolated for life. And the only one to become a synonym for contagion.

*According to Dr. S. Josephine Baker, “I literally sat on her all the way to the hospital; it was like being in a cage with an angry lion.”
**None of the accounts describe how you get a stool sample from an unwilling subject. The mind boggles.