Mary Mallon

Mary Mallon
Mallon in isolation
Born	(1869-09-23)September 23, 1869 Cookstown, County Tyrone, Ireland
Died	November 11, 1938(1938-11-11) (aged 69) North Brother Island, East River, New York, U.S.
Cause of death	Pneumonia
Resting place	Saint Raymond's Cemetery
Residence	United States
Nationality	Irish by birth; American citizen by naturalization after immigration
Other names	Mary Brown
Occupation	Cook
Known for	Asymptomatic carrier of typhoid fever

Mary Mallon (September 23, 1869 – November 11, 1938), better known as Typhoid Mary, was the first person in the United States identified as an asymptomatic carrier of the pathogen associated with typhoid fever. She was presumed to have infected 51 people, three of whom died, over the course of her career as a cook. She was twice forcibly isolated by public health authorities and died after a total of nearly three decades in isolation.

Mary Mallon was born in 1869 in Cookstown, County Tyrone, in what is now Northern Ireland. She immigrated to the United States in 1883 at the age of 15. She lived with her aunt and uncle for a time and later found work as a cook for affluent families.

From 1900 to 1907, Mallon worked as a cook in the New York City area for seven families. In 1900, she worked in Mamaroneck, New York, where, within two weeks of her employment, residents developed typhoid fever. In 1901, she moved to Manhattan, where members of the family for whom she worked developed fevers and diarrhea, and the laundress died. Mallon then went to work for a lawyer; she left after seven of the eight people in that household became ill.

In 1906, she took a position in Oyster Bay, Long Island, and within two weeks 10 of the 11 family members were hospitalized with typhoid. She changed jobs again, and similar occurrences happened in three more households. She worked as a cook for the family of a wealthy New York banker, Charles Henry Warren. When the Warrens rented a house in Oyster Bay for the summer of 1906, Mallon went along too. From August 27 to September 3, six of the 11 people in the family came down with typhoid fever. The disease at that time was "unusual" in Oyster Bay, according to three medical doctors who practiced there. Mallon was subsequently hired by other families, and outbreaks followed her.

In late 1906, one family hired a typhoid researcher named George Soper to investigate. Soper published the results on June 15, 1907, in the Journal of the American Medical Association. He believed Mallon might be the source of the outbreak. He wrote: