Mary Mallon was an Irish cook who was imprisoned for life for not washing her hands properly prior to preparing food. Mallon, an immigrant often referred to as “Typhoid Mary” unknowingly spread typhoid as she did not see a need to wash her hands frequently. Everywhere Mallon worked, people became sick or died which eventually lead to her apprehension. In 1882, the German physician Robert Koch had published a paper proving that microorganisms transmit disease. This discovery gave birth to microbiology. In 1907, New York City, United States of America sanitary expert George Soper had tracked the typhoid outbreak down to Mallon. Suspecting Mallon was immune to the disease but still a carrier, Soper pleaded with Mallon to be tested, however Mallon refused, and angrily chased Soper off with a dining fork. After being visited by the health board of New York City, Mallon found herself under quarantine where she remained for 3 years until she swore an affidavit to never work as a cook again. 5 years afterwards, another outbreak of typhoid occurred, this time traced back to Mary Brown, however Brown was Mallon working under an assumed identity. Mallon was quarantined once again, never being let out and dying from pneumonia while imprisoned