The Enigmatic Case

Mysterious Case of "Typhoid Mary": A Medical Mystery Yet to Be Solved

The early 1900s were when New York was crowded and cursed with sickness; probably the strangest of those cases involved one Mary Mallon, popularly known as "Typhoid Mary." Hers is the story of how modern disease tracking began.

Mary Mallon was an Irish immigrant who cooked for well-off families. Over the years, many people fell gravely ill with typhoid after she had prepared meals for them. The weird thing about it was that Mary seemed perfectly healthy. Typhoid was one of the major diseases then and was associated with bad water or food. The fact that a perfectly healthy person could spread it wasn't really known. It wasn't until 1906 that sanitary engineer Dr. George Soper was called into the investigation of a typhoid outbreak in Oyster Bay on Long Island. There he encountered evidence that Mary had worked as a cook with the family immediately before they fell sick. Typhoid was following Mary to every home she went to. Soper's hypothesis was that Mary might be a "healthy carrier" of the disease-that is, she had the bacteria but didn't become ill herself. It was an innovative concept at that time. To prove his hypothesis, Soper requested from Mary samples of her blood, urine, and stool. She refused; she felt OK, and she didn't believe she could do any harm to anybody. But the health authorities proved more insistent.

They isolated her and ran some tests on her. The tests proved that she was carrying the typhoid bacteria in her gallbladder. It was proof of Soper's hypothesis. Mary was one of the first known healthy carriers of a disease.

Because of this, she spent most of her life quarantined to North Brother Island in the East River. She was there for more than 20 years before she died in 1938. Mary's case changed public health forever. It showed just how carriers, like herself, could spread diseases and led to new health rules and laws concerning food safety. It brought out the fact that there had to be better ways of communicating about health issues with compassion. Typhoid Mary is a lesson in the way diseases are transmitted and the weighing of considerations. It brings into mind the balance between keeping people safe and considering the rights of a particular individual. Of course, we know so much more now about how diseases are carried due to Dr. Soper and others, which helped to create many of our modern health practices.