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Who Was Typhoid Mary, The 20th-Century “Super-Spreader”?


Mary Mallon in a hospital bed. June 20, 1909 issue of The New York American/Wikimedia Commons

The now-infamous "Typhoid Mary" was born Mary Mallon on September 22, 1869, in County Tyrone, Ireland. Working as a cook in 20th-century New York, Mary moved from household to household, leaving a trail of typhoid outbreaks in her wake, making her a "super-spreader" before the term existed.

She herself was an asymptomatic carrier – the first person to be identified as such in the US. And today, her name is synonymous for anyone who deliberately or not spreads pathogens, resulting in the contamination of others. But who exactly was Mary Mallon? What made her such an efficient transmitter of disease? And how many deaths is she directly responsible for?


Mary's Story – Part I

Her story starts in 1883, when – still a teenager – she boarded a ship bound for New York to start a new life. There, she moved in with her aunt and uncle and began a not-so-illustrious career as a family cook for the city’s elites, spending years jumping from job to job. Mary has been described as having a “violent temper” and reports paint a picture of a hot-headed, stubborn, and obstinate individual with nomadic impulses and a blatant disregard for basic hygiene.

“Mary appeared to be a person who moved about a good deal; she did not remain long in any situation,” wrote George Soper (more on him later) in The Curious Career of Typhoid Mary.

Indeed, it was following one of these “situations” that she first rose to national attention. Mary was working for New York banker Charles Henry Warren and his family in the summer of 1906, feeding the 11 guests staying at his rented second home in Oyster Bay, Long Island. By late August, six of those guests had fallen ill with typhoid and no one knew why.


A Little Bit of Background

Typhoid, caused by the Salmonella serotype Typhi, was (and, in some places, still is) a major killer. Symptoms include weakness, stomach pain, headache, bowel problems (diarrhea or constipation), cough, loss of appetite and, in some cases, rashes of flat, rose-colored spots. Without antibiotic treatment, it can kill one in every four victims.

In Mary's New York, germ theory had become a well-established explanation for disease progression and urban sanitation measures were being introduced to help prevent sickness from spreading. Typhoid fever, when it appeared, was considered to be a disease of poverty, prevalent in slums where sanitation was lacking and disease was rife. I.e. not something you would expect to come across in a well-to-do household like, say, that of Charles Henry Warren.

Mary's Story – Part II


In the winter of 1906, a sanitary engineer, George Sober, was called in to find out what had happened at the Oyster Bay property – and, so the owner hoped, find irrefutable proof that the house was now typhoid-free. Initially, he suspected a batch of bad clams, but when he checked the house for contamination, he found no evidence. It was then that he thought there may have been a human carrier, culling the pool of suspects until he was left with just one – Mary Mallon, the house cook, who departed soon after the incident.

With further investigation, Sober was able to narrow in on the source of the outbreak to just one meal. That meal was an especially popular dessert made with ice cream and chunks of fresh peach. Unlike most recipes, this ice-cold dish required no heating (which would kill the Salmonella bacteria), making it the ideal vector for the typhoid-causing bug – particularly when your cook’s hygiene routine is, at best, erratic.

Now that Mary had been named and shamed, Sober began the surprisingly difficult process of hunting her down. It was during this time that he got speaking with some of her past employees, uncovering a history speckled with typhoid outbreaks and learning of a woman who never stayed in one place for very long.

In March 1907, he found her. She was working as a cook for a family on Park Avenue in the Upper East Side. “The laundress had recently been taken to the Presbyterian Hospital with typhoid fever,” he recalls. “And the only child of the family, a lovely daughter, was dying of it.”


But when he approached her and told her his theory – that is, that he believed she was unwittingly spreading the disease – she reacted with violence, apparently seizing a carving fork and advancing towards him. This move prompted Sober to make a run for it. He returned and explained again, but she continued to deny it. Long story short, Sober had her put into custody with the help of the New York City Health Department.

But even under lock and key and with her status as a typhoid carrier confirmed by a stool sample, Mary refused to cooperate. She made a (failed) break for it on March 20, and when Sober promised to set her free in return for her assistance, she refused to answer any questions.

"She pulled her bathrobe about her and, not taking her eyes off of mine, slowly opened the door of her toilet and vanished within. The door slammed. There was no need of my waiting. It was apparent that Mary did not intend to speak to me. So I left the place," he wrote.

For three years, Mary lived in residence at the Riverside Hospital on North Brother Island in isolation as the hospital attempted to treat her. It didn't work – despite being the picture of health, she continued to carry the Salmonella bacteria. Then, in 1910 she was released with the provision that she would report to the Health Department once every three months and, very importantly, relinquish her career as a cook. A promise she did not keep.


Without a doubt knowing it was strongly frowned upon, Mary Mallon took up various aliases (Mary Breshof, Mary Brown, etcetera) and took on jobs in hotels, inns, restaurants, even hospitals. (Agencies responsible for placing cooks with wealthy families now knew her by sight, so she was prevented from taking up posts in private households.) But despite these various attempts to keep her identity hidden, she was caught again. 

June 20, 1909 issue of The New York American/Wikimedia Commons

Mary's Story – Part III

In 1915, she was found working at the Sloane Maternity Hospital in Manhattan after an outbreak of typhoid fever, which had caused 23 staff members to fall ill and two to die. At this point, she was going by the name of Mary Brown but her colleagues had nicknamed her "Typhoid Mary". This time when the health officials came a-calling, she appears to have put up little fuss. In his biography, Sober remembers a much more subdued Mary.

"Mary was on the island the second time for twenty-three years. During this long period she never once tried to escape. Did she want to regain her liberty after her second arrest? I believe she did not," he wrote.


"She was as strong as ever, but she had lost something of that remarkable energy and activity which had characterized her young days and urged her forward to meet undaunted whatever situation the world presented to her... In the last five years, although she had been free, there had been times when she had found it hard to fight her battles unaided. On North Brother Island the City afforded her a comfortable place to live – a place where she could cook and sleep and read to her heart's content."

Mary wiled away the rest of her days working in the laboratory, where she learned to make simple routine tests. She was even given permission to visit the mainland on occasion, where she perused her old Manhatten haunts and ventured into Queens to call on family (who, we are told, "were not particularly glad to see her"). She always returned to her North Brother Island bungalow. 

Then, on November 11, 1938, Mary died. According to a biopsy, the cause of death was terminal bronchopneumonia. Her body was promptly taken and buried in a grave at St. Raymond's Cemetery in the Bronx specifically bought for that very purpose. There was no autopsy and her funeral was a somber, relatively low-key affair with just nine attendees. 

"Of all those in the City employ who had known Mary Mallon and had seen her come and go for so many years, there was not one who followed her to her grave," Sober recalled.


Mary's Legacy

Fifty-one infections and three deaths have been attributed to Mary but there could very well be more. And while that is not even close to the number linked to a farm hand called Tony Labella, another New Yorker, "Typhoid Mary" has become a synonym for anyone who knowingly or not spreads something undesirable – like disease-causing bacteria and viruses. She has even inspired a Marvel character, a supervillain and enemy of Daredevil who possesses a number of (limited) psionic powers. 

Today, we also know how Mary was able to remain so healthy and carry a potentially deadly bacteria for so many years. Researchers at Stanford University have shown how S. typhi can live inside white blood cells called macrophages (Greek for "big eater") and alter the metabolism for its own benefit. Indeed, as many as 1 to 6 percent of people infected with S. typhi may become chronic asymptomatic carriers – just like Mary. 


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