Mary Mallon could not have been too pleased at the presence of official-looking men identifying themselves as doctors accusing her of carrying typhoid fever (even though she bore none of the symptoms) and demanding biological samples from her. But the New York health authority had good reason to believe that Mary, who was the governess to at least three families who succumbed to typhoid, was the common link. And despite Mary’s vehement objects they quarantined her.

On this day, March 27, in 1915, Mary Mallon was quarantined a second time. She was released from quarantine the first time in the vain belief she would not take up cooking jobs, which is how she infected the first families. But she was caught working as a cook once again.

Mary was allowed to leave North Brother Island, just off the coast of the New York, after convincing the clinic officials she was of no threat to anyone. Provided she would not prepare meals for anyone else, they saw no reason to keep her. But it was cooking that Mary went back to. Soon another flare-up of typhoid fever was traced back to her, she was apprehended and quarantined for good at the clinic. To her last day she maintained she was not sick, but an autopsy done postmortem revealed she did have a live typhoid bacteria culture in her.