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Topic: Patient Zero

Mary Mallon(1870?-1938), known as "Typhoid Mary". She was the first person identified as a carrier of typhoid bacilli in the United States. Herself immune to the disease, she spread typhoid while working as a cook in the New York City area. She is pictured here after having been institutionalized on Brother Island where she stayed from 1914 until her death in 1938. (Getty Images/Bettmann)

Why finding patient zero matters

Mary Elizabeth Williams