Posted by: Glow-worm PJ6 NOV 2013
The 75th anniversary of the death of Mary Mallon falls on 11 November 2013. She is better known as Typhoid Mary, the first person in the US to be identified as an asymptomatic carrier of typhoid.
Mary was born in Cookstown, County Tyrone, on 23 September 1869. Aged 15, she emigrated to the US, where she found work as a domestic servant. She was hired as a cook by a New York banker for his summer vacation of 1906, but in one week six out of the 11 members of the household fell ill with typhoid.
The property’s owner hired a typhoid researcher, who revealed that the disease had followed Mary in her work as a cook, although she appeared perfectly healthy. She was ordered to provide stool samples, which revealed Salmonella typhi. She refused to give up her job as a cook, and the city health inspector instructed that she be held in isolation, where she was kept for three years.
Mary was released in 1910 and agreed to stop working as a cook. However, she soon changed her name and resumed her old occupation.
She was finally tracked down in 1915 when a typhoid epidemic broke out at New York’s Sloane Hospital for Women. She was arrested and returned to quarantine, where she remained until her death in 1938.
The puzzle of asymptomatic typhoid carriers has only recently been solved. Researchers at Stanford University found that certain strains of S typhi are able to penetrate and survive inside the host’s macrophage cells, avoiding detection by the immune system. They then use the genetic code of the macrophage to alter intracellular energy production, switching from using glucose as a substrate to the fatty acids favoured by S typhi.
This discovery offers hope for the development of therapies that could potentially block the activity of S typhi.