
Typhoid Mary’ aka Mary Mallon (1869-1938): the super-spreader before the term even existed
Nicknamed "Patient Zero", the woman most of us know as 'Typhoid Mary,' was born on, September 23, 1869, in County Tyrone.
Mary Mallon was born on September 23, 1869, in Cookstown, Co. Tyrone. Like so many people in post-famine Ireland Mary emigrated to the United States in 1884. Upon arriving in New York she began working as a domestic servant and with a flair for cooking she soon became a household cook for several families.
A New York banker Charles Henry Warren hired Mary as a cook for the families’ summer vacation in Oyster Bay, Long Island. Soon after their arrival one of Warren’s daughters fell ill with typhoid fever. Following this Mrs. Warren and two maids became ill as well as the gardener and another Warren daughter. In the end, six of the eleven people in the house were diagnosed with typhoid.
George soper wasย not your typical detective. He was a civil engineer by training, but had become something of an expert in sanitation. So when, in 1906, a landlord in Long Island was struggling to trace the source of a typhoid outbreak, Soper was called in. The landlord had rented his Long Island house to a bankerโs family and servants that summer. By late August, six of the houseโs 11 inhabitants had fallen ill with typhoid fever.
Soper had been previously hired by New York state toย investigateย disease outbreaksโโI was called an epidemic fighter,โ he later wroteโand believed that typhoid could be spread by one person serving as a carrier. In Long Island, he focused his attention on the cook, Mary Mallon, who had arrived three weeks before the first person became ill.
What Soper discovered would demonstrate how an unwitting carrier could be the root of disease outbreaks, and, later, spark a debate about personal autonomy when itโs pitted against public health.
Combing through the roster of wealthy New Yorkers who had employed Mallon in their summer homes between 1900 and 1907 he found a trail of 22 infected people. Typhoid fever is a bacterial infectionย typically spreadย through food and water contaminated by salmonella. Patients fall ill with high fever, diarrheaโand, before antibiotics were developed to treat it, sometimes delirium and death.
At that time, without regulated sanitation practices in place, the disease was fairly common and New York had battled multiple outbreaks. In 1906, the year Soper began his investigation, a reported 639 people had died of typhoid in New York. But never before had an outbreak been traced to a single carrierโand certainly not one without any symptoms themselves.
Soper learned that Mallon would often serve ice cream with fresh peaches on Sunday. Compared to her hot, cooked meals, heย deducedย that โno better way could be found for a cook to cleanse her hands of microbes and infect a family.โ
Hunting the carrier
Four months after he started the investigation, Soper found Mallon working in a Park Avenue brownstone. The 37-year-old Irish cook, he laterย described, was โfive feet six inches tall, a blond with clear blue eyes, a healthy color and a somewhat determined mouth and jaw.โ When confronted with his evidence and a request for urine and feces samples, she surged at Soper with a carving fork.
Dr. S. Josephine Baker, an up-and-coming advocate of hygiene and public health, was dispatched to convince Mallon to provide samples, but was also chased away. Baker, whose father had died of typhoid, later made it her mission to promote preventative medicine (and became the first woman to earn a doctorate in public health). โIt was Maryโs tragedy that she could not trust us,โ Baker laterย wrote.
Finally, Mallon was escorted by Baker and five policemen to a hospital whereโafter a nearly successful escape attemptโshe tested positive as a carrier forย Salmonella typhi, a bacteria that causes typhoid. This would later be confirmed by more tests. She was quarantined in a small house on the grounds of Riverside Hospital. The facility was isolated on North Brother Island, a tiny speck of land off the Bronx.
Mallon herself had no symptoms of typhoid and didnโt believe she could be spreading it. Itโs likely Mallonย never understoodย the meaning of being a carrier, particularly since she exhibited no symptoms herself. The only cure, doctors told Mallon, was to remove her gallbladder, which she refused. She was dubbed โTyphoid Maryโ by theย New York Americanย in 1909 and the name stuck.
In a hand-writtenย letterย to her lawyer that June, Mallon complained. โI have been in fact a peep show for everybody. Even the interns had to come to see me and ask about the facts already known to the whole wide world. The tuberculosis men would say โThere she is, the kidnapped woman,โโ she wrote. โDr. Park has had me illustrated in Chicago. I wonder how the said Dr. William H. Park would like to be insulted and put in the Journal and call him or his wife Typhoid William Park.โ
In 1909, she sued the New York City Department of Health and the case was brought to the Supreme Court. In the court of public opinion, Mallon had stirred a debate over individual autonomy and the stateโs responsibility in a public health crisis. In the court of law, her lawyer argued she had been imprisoned without due process.

The court declined to release her,ย sayingย โit must protect the community against a recurrence of spreading the disease,โ but Mallon was freed early the following year by the cityโs new health commissioner. He agreed on the condition that she stop cooking.
Without other skills and unconvinced that her condition was a danger, Mallon drifted back to her old job around New York and New Jersey. She prepared meals for a hotel, a Broadway restaurant, a spa, and a boarding house. When, in 1915, a typhoid outbreak sickened 25 people at Sloane Maternity Hospital, George Soper was again called to investigate. The cook, โMrs. Brown,โ was discovered to be Mallon.
A life in exile
Mallon was sent back to North Brother islandโpermanently. She spent her days reading and working in the laboratory preparing medical tests. She died there of a stroke in 1938, after a quarter-century of quarantine. She never admitted to being a carrier of typhoid, and perhapsย without the education to understand it, actually never believed it. Nine people attendedย her funeralย at St. Lukeโs in the Bronx.
During the course of two outbreaks, at leastย 51 peopleย caught typhoid through Mallon, and three died. The number of cases was probably much higher. โThe story of Typhoid Mary indicates how difficult it is to teach infected people to guard against infecting others,โ Soper warned. But the authorities had already changed the way they responded to such threats. At the time of Mallonโs death, more thanย 400 healthy carriersย of typhoid who had been identified by New York officials, and none had been forced into confinement.
The legacy of โTyphoid Maryโ as an asymptomatic vessel for disease led to the theory of โsuperspreadersโ that has surfaced in disease outbreaks ever since. โSince โTyphoid Maryโ was discovered, the whole problem of carriers in relation to infectious diseases has assumed an immense importance,โ Soperย saidย in a speech in 1913, โan importance which is recognized in every country where effective public health work is done and in every army where communicable disease has been brought under control.โ