Her real name was Mary Mallon, but the process that gave her the name Typhoid Mary began in 1906, when a public health official named George Soper researched a series of typhoid outbreaks in well off families. All of them seemed to have hired an Irish cook, about 40 years old, just weeks before the outbreak, and then had this cook leave just weeks after the outbreak. Knowing that typhoid was caused by less than stellar hygenic practices in food preparation, it became apparent this cook was a "healthy carrier" that was spreading the disease although she was not showing symptoms. Once Mary Mallon was identified as the suspect, she was tested for typhoid and held in quarantine when the tests were positive and she refused to quit cooking. Finally, she accedes to stop being a cook in exchange for her freedom in 1910. Over the next five years, Mary Mallon disappears, and repeated outbreaks of typhoid appear around an Irish cook serving various families. When she was located after a typhoid outbreak at a hospital, public health officials placed Mary Mallon in quarantine for good.