Sober had traced her history of contact, primarily through employment agencies, and found typhoid cases wherever she worked. Today, we would call him a contact tracer, a person who traces the movements of a person infected with a pathogen, like typhoid, and identifies who they have been in contact with in order to prevent further spread of the illness.Īfter studying potential sources like contaminated water, Sober determined contact with Mallon was the cause of the outbreak, and in 1907, she became the first person in North America identified and analyzed as a 'healthy carrier' of typhoid. The family hired sanitary engineer George Sober to determine how the illness had spread through the family. By that September, within a month of beginning work, typhoid fever had spread to six of the 11 people in the household. She emigrated from Ireland to New York in about 1883, and in summer 1906, was a temporary cook in the home of a wealthy banker. Not just a turn-of-phrase, Typhoid Mary was a real woman named Mary Mallon. One such person was the infamous 'Typhoid Mary.' Many people have quickly learned what it means to be an asymptomatic carrier, defined by the Centers for Disease Control and Prevention as 'passive or healthy carriers…who never experience symptoms despite being infected.' 'Human carriers,' as they were once called, were conceived of by scientists as early as the 1870s. The term 'asymptomatic' has been prevalent in every internet search engine since the COVID-19 health crisis began dominating the lives of people all over the globe.

Typhoid Mary by Judith Walzer Leavitt