Typhoid Mary: The Original “Super-spreader”

On this day, 15th June in 1907, George Soper published a paper in the Journal of the American Medical Association in which he identified a woman as the source of numerous outbreaks of typhoid fever in New York. This woman was named Mary Mallon, however she is more commonly known by her more famous nickname: “Typhoid Mary”.

Who was Typhoid Mary?

Mary Mallon was born in Cookstown, County Tyrone in 1869. Mary emigrated to the US and found herself working as a cook for wealthy families in New York. 

The families Mary worked for and the other domestic staff started to become ill. They were identified as having typhoid fever.  

Typhoid fever, commonly just called typhoid, is caused by the Salmonella typhi bacteria. While most types of Salmonella might give you a nasty case of food poisoning, this type causes a potentially life-threatening infection if not treated. 

Mary, feeling perfectly healthy, moved on to the next job. 

This was until she took a job with the family of Charles Henry Warren in 1906. Of the 11 people in the house, 6 became ill with typhoid. Warren hired George Soper, a sanitary engineer, to track down the source of the outbreak. 

While Soper initially thought that freshwater clams could be the culprit, he did track the infection back to Mary. He followed Mary’s career from 1900 up to 1906 and discovered that all but one house Mary had worked in had seen cases of typhoid.  

Although Mary felt perfectly well, it seemed that typhoid followed her wherever she went. Mary was what we now call an asymptomatic carrier. Asymptomatic carriers are people that are able to spread disease, despite not feeling unwell. 

Mary was identified as the first asymptomatic carrier of Salmonella typhi. This meant she carried the bacteria in her digestive system but it didn’t make her ill. Unfortunately the food Mary was preparing was becoming contaminated by the bacteria and making the families she worked for ill. Some of this contamination may be attributed to poor hand washing and food hygiene.

Soper informed the New York City Health Inspector, Dr S. Josephine Baker (the first woman to achieve a doctorate in public health) who ordered Mary be brought in for testing. The police arrived at the house Mary was living, however she wouldn’t come quietly. 

After a 5 hour manhunt, Mary was arrested and forced to provide samples. After testing, her stool was found to test positive for Salmonella typhi and she was quarantined in Riverside Hospital on North Brother Island. The hospital was used to quarantine patients with infectious diseases such as tuberculosis and typhoid. 

This, however, was not the end of Mary’s story. After 2 years, she was released on the condition that she would not work as a cook again. At the time, cooking was the best source of income Mary could find, and although she tried work such as ironing, she found that it did not pay as well. Unable to find work as Mary Mallon, she used aliases such as Mary Brown to find work as a cook for the next 5 years. 

As a result, Mary was identified as the source of more outbreaks and was once again quarantined on North Brother Island, where she lived and worked in the Hospital until her death in 1938. 

Mary has since been identified as the source of at least 51 cases of typhoid, 3 of whom died. Mary’s case was a particularly tragic one. At the time of her death, at least 400 asymptomatic carriers of Salmonella typhi had been identified and none had been quarantined indefinitely in the same way as Mary. 

Now we know that around 1 in 20 people who survive typhoid will become carriers of the infection and are capable of spreading the disease long after they have recovered. The city’s approach of imprisoning Mary on North Brother Island has since been described as overreaching and that Mary was a victim of public hysteria.

While we no longer arrest and imprison people for being asymptomatic carriers of disease, countries have gone into lockdown, some imposing curfews and restrictions on their citizens, in the wake of COVID-19. Quarantining infectious people is still the most effective way to prevent the spread of disease, however, people can not be quarantined indefinitely.

Lessons we can use during COVID-19

Mary’s legacy has led to the concept of “super-spreaders” discussed even today. Super-spreader is a term used to describe a person that is responsible for a larger than average number of cases. The COVID-19 pandemic is no exception and is said to have its own super-spreaders

Mary was villainized by the media at the time and public opinion remains hostile towards her. The nickname “Typhoid Mary” lives on today, used to describe a person willingly spreading disease. In Mary’s case, the idea of an asymptomatic carrier wasn’t fully understood and she struggled to conceive how she could be spreading a disease she didn’t believe she had. 

Many people are able to spread COVID-19 without realising it or feeling ill themselves. There is still a stigma today around unwittingly spreading disease, much like in Mary’s time, and to be accused of spreading disease can feel like a personal attack. However, we all need to take responsibility for slowing the spread, whether we have symptoms or not. 

Everyone plays a part. 

Lessons learned from the sad story of Mary Mallon are still relevant over 100 years later:

I hope the story of Mary Mallon can serve as a cautionary tale and that Mary can be seen as a valuable teacher today rather than the villain she was portrayed as while she was alive. 

But what do you think? Was she misunderstood or a menace to society? Let me know in the comments.

---

Related Posts