I first saw Mary Mallon thirty-two years ago, that is, in 1907. She was then about forty years of age and at the height of her physical and mental faculties. She was five feet six inches tall, a blond with clear blue eyes, a healthy color and a somewhat determined mouth and jaw. Mary had a good figure and might have been called athletic had she not been a little too heavy. She prided herself on her strength and endurance, and at that time and for many years thereafter never spared herself in the exercise of it.
We’re on the cusp of a breakthrough in medical science in 1908 – viruses and bacteria have been conclusively shown to be the cause of illness, vaccines are being developed, antibiotics are just around the corner – but for the bulk of humanity, little has changed since Victorian times. All these advances are as yet nothing when set against a stubborn person who is carrying an infectious disease.
Typhoid is a bacterial infection which results in a high fever, weakness, abdominal pain, constipation and headaches. In 1908 it had a mortality rate of something like 20%. Mary Mallon was a carrier of the disease, but never showed any symptoms. She worked as a cook in at least six wealthy households in New York, and was famous for a signature dish of ice cream and frozen peaches. “No better way,” said investigator George Sopor, “could be found for a cook to cleanse her hands of microbes and infect a family.” It was shown that least 51 people were infected by Mary, with three fatalities, but some have the latter figure as high as 50.
After three years of quarantine, Mallon was released after agreeing that she would “change her occupation (that of a cook), and would give assurance by affidavit that she would upon her release take such hygienic precautions as would protect those with whom she came in contact, from infection.” However, after two years working as a laundress, she changed her name to Mary Brown and returned to her former occupation, starting several other major outbreaks. Police were finally able to find and arrest her in 1915, and she spent the remainder of her life in quarantine on North Brother Island.
You can find an episode about Typhoid Mary at Stuff You Missed In History Class.