Mary Mallon was an exquisite cook. The meals she prepared were so well received that the Irish immigrant was offered numerous jobs cooking for wealthy families across New York. Unfortunately, while her abilities in the kitchen could have made her a culinary name, in the end it was her inability to wash her hands that gained her a new nickname: Typhoid Mary.
Typhoid is a bacterial infection caused by Salmonella typhi, which leaves the infected suffering from a fever and problems throughout their digestive system. Usually typhoid is spread through food and water contamination and poor hygiene levels, but Mary caused outbreaks in the relatively sanitary homes of wealthy families.
Everywhere Mary cooked, typhoid descended upon the households, and it wasn’t long before the link between her and the outbreaks was discovered. Mary’s reluctance to wash her hands properly led to plates of infection being served to everyone she cooked for. Despite dozens of people falling ill around her– and with three dropping dead – remarkably Mary still showed no sign of infection. Because of this, when Mary was told by authorities that she was carrying the disease, she denied it. Up to six per cent of people infected with Salmonella typhi are thought to be asymptomatic carriers, and Mary was one of them.
As the bacteria continued to live inside her, she showed no signs of illness and became a mass spreader. Unwilling to give up her job, Mary changed her name and continued cooking in denial of her harmful ways. Responsible for suffering, death and even a hospital outbreak, at the time she and many others were unaware of the link between hand washing and some diseases. The story of Typhoid Mary shows how this simple act can defend against an outbreak of disease.