Mary Mallon, known as Typhoid Mary, was the first healthy person in the United States to be identified as a carrier of typhoid fever. Mary worked as a cook and unknowingly infected 53 different people: three of whom died from typhoid. She became famous, partly because she was the first healthy carrier of typhoid, but mostly because she adamantly refused to admit her role in spreading the disease and would not take the necessary precautions to prevent its spread.
It is now known that typhoid fever can be spread by food or water that has been handled by a carrier. Carriers are generally healthy people who have survived typhoid and have no further symptoms, but continue to have the typhoid bacteria surviving in their body. In Typhoid Mary's case, she may have actually been born with typhoid, as her mother was infected. Carriers can pass the bacteria along by poor hygiene when handling food and drink.
Mary Mallon made a living as a cook in the New York City area in the early 1900's. Between 1900 and 1907, she infected 22 people with typhoid fever, with one fatality. At times, Mary cared for the people in her household who came down with typhoid, unknowingly making them even more ill. Typhoid Mary changed employment frequently, as her employers and their families became ill.
New York City sanitary worker George Soper, hired by the landlord of a house that Mary had worked at, investigated that specific typhoid outbreak. Soper hypothesized that Mary could be a possible carrier of typhoid fever. When he explained to Typhoid Mary that she might be spreading typhoid, she absolutely refused to cooperate with his requests for stool and urine samples. She claimed to have had negative test results for typhoid, although she may have been in remission at this time.
Soper continued to try and convince Mary Mallon that she was a typhoid carrier, but at this time, the idea of a healthy person being able to spread disease was not well-known and seemed unlikely. Soper published his findings in The Journal of the American Medical Association in 1906. Typhoid Mary became convinced that she has being harassed and persecuted for no reason. She was soon taken into custody.
The health inspector in New York City found Typhoid Mary to be a carrier. She was put in quarantine for three years in a hospital on an island off of New York, and released when she promised not to work with food any more. As soon as she was released, however, she began working as a cook again, under the name of Mary Brown. She was forcibly quarantined again, for the rest of her life, becoming somewhat of a celebrity and granted interviews.
Mary Mallon died of pneumonia in 1938 at the age of 69, six years after being paralyzed by a stroke. An autopsy was conducted, finding live typhoid bacteria present in her gall bladder. Many historians view Mary as a symbol of the prejudice that existed at the time against Irish immigrants and the working class in general. "Typhoid Mary" is now used as a generic term for someone who is a danger to the public because they carry a dangerous disease.