The tragic fate of ‘Typhoid Mary’

In the 19th century, typhoid was a widespread epidemic from which one in ten infected people died. The infectious disease typhoid was caused by the bacterium Salmonella enterica. Hygiene conditions were often appalling, which provided ideal conditions for the epidemic to spread. As typhus was long considered incurable – with symptoms including abdominal pain, nausea, fever and impaired consciousness – those who fell ill were placed in quarantine. One of them was Mary Mallon, who, however, showed no symptoms whatsoever. Mary Mallon was the first person in the United States to be identified as an asymptomatic carrier of typhoid fever. Mary Mallon was a so-called ‘chronic carrier’ who, between 1900 and 1907, whilst working as a cook in various households in New York City and on Long Island, infected nearly two dozen people with typhoid fever without realising it. The whole affair came to light after six people in an eleven-member household in Oyster Bay fell ill with typhoid in 1906. The head of the household subsequently commissioned George Soper, a public health engineer from the New York City Department of Health, to investigate the outbreak. His months-long investigation eventually led him to the 37-year-old cook Mary Mallon, whom he was able to link to 22 cases of typhoid fever. Typhoid had broken out shortly after Mary had worked as a cook in each of these households. Today, typhoid can be easily treated with a vaccination, but back then it was one of the eight worst and deadliest epidemics, which is why those carrying the disease were isolated from society. Suspecting that Mary was the mysterious source of the typhoid outbreaks, the public health officer George Soper visited her in March 1907 at her new job as a cook in a suburban house in Westchester County to take samples from her. But instead of welcoming Soper, Mary brandished a carving knife and refused to provide samples of her urine, stools or blood. Her right to privacy, however, soon became irrelevant when it became clear that Mary had presumably passed the typhoid pathogen on to guests and staff without ever falling ill herself. Five police officers and a doctor arrived to take Mary to a New York hospital. There, tests confirmed that, although she showed no symptoms whatsoever, she was carrying Salmonella Typhi, the bacterium that causes typhoid fever. The term ‘chronic carrier’ was coined as a result of her case. Mary had cooked for eight families, seven of whom were affected by typhoid – a total of 51 cases of typhoid and three deaths were later attributed to her.