If you hear the term “Typhoid Mary” today, it is usually about a person who spreads something undesirable, e.g., a common cold.
But the original Typhoid Mary was much more than a germ host. In the first place, Mary Mallon, an asymptomatic carrier of typhoid fever, never considered herself to be a carrier at all. Yet she was the cause of more than 50 serious cases of illness and at least three deaths.
Mary was born in Ireland in 1869. At 14, she emigrated to the United States to live in New York with an aunt and uncle. By the time they died, Mary was already earning a great reputation as a cook. Wealthy New Yorkers competed to hire her for her legendary desserts: peach ice cream was her specialty.
In 1900, two weeks after Mary started a new job, several people in the house developed typhoid. At her next job, the laundress contracted typhoid and died. When Mary began working for a lawyer, his whole household came down with typhoid. In 1906, she accompanied the Warren family on vacation to Oyster Bay, as their cook. The family had scarcely arrived when Mrs. Warren and both of her daughters became ill with typhoid. Shortly afterward, three servants also became ill.
A civil engineer named Dr. Soper was hired to investigate. Soper was intrigued that so many wealthy New Yorkers were contracting typhoid, a disease caused by bacteria found in human and animal waste, typically found in impoverished areas with poor sanitation.
Soper soon discovered Mary Mallon was a link between the outbreaks. There were 22 cases of typhoid, in seven of the eight families who had employed her. Dr. Soper suspected Mary unwittingly transmitted the disease by handling food with unwashed hands.
By the time Soper identified her, Mary no longer worked for the Warrens. There was no sign of her until 1907, when a typhoid outbreak on Park Avenue claimed one life and endangered two others.