Super Spreader: The Strange Story of Typhoid Mary

In the winter of 1906, Mrs. George Thompson called upon Dr. George Soper, known around New York as an “epidemic fighter,” to investigate the source of a typhoid outbreak that had occurred among renters in her Oyster Bay summer home several months prior.

After finding no issue with the well, the outhouse, the food supplies, or any other part of the property that might have generated germs, Soper considered the possibility that the carrier could have been a healthy person—an idea that wasn’t widely accepted at the time. By process of elimination, he landed on a likely culprit: the cook, a 37-year-old woman named Mary Mallon.

Mallon, described by the other servants as “not particularly clean,” had arrived at the Thompson home on August 3, 1906. Just weeks later, between August 27 and September 3, six out of the house’s 11 occupants had contracted typhoid fever. Though most of her dishes were hot and prepared at temperatures that would have killed any bacteria, Mallon had served ice cream with fresh peaches one Sunday, which some of the house guests ate with gusto.

Before searching for Mallon herself, Soper followed her trail of employment all the way back to September 1900, unearthing a total of seven households in New York and Maine that had suffered typhoid outbreaks during Mallon’s tenure.

“In nearly every instance, a well-to-do and socially prominent family, soon after moving from the city to the country for the summer, experienced an outbreak of typhoid fever. In no instance had its cause been satisfactorily explained,” Soper recounted in the Bulletin of the New York Academy of Medicine. "The cook always left soon afterward. She had never been suspected."

Soper decided it was time to track Mallon down.

A Mean, Unclean Quarantine Queen

In early 1907, Soper paid Mallon a visit in Manhattan, in an old-fashioned house on Park Avenue and 60th Street where she was working, once again, as a cook.

“I was as diplomatic as possible, but I had to say I suspected her of making people sick and that I wanted specimens of her urine, feces, and blood,” Soper wrote.

Mallon seized a carving fork and chased Soper from the premises.

After another unsuccessful attempt to reason with Mallon, Soper asked New York City’s Department of Health to intervene. So Dr. Sara Josephine Baker came calling at the Park Avenue estate, and Mallon made a run for it, evading capture for three hours before police found her in a neighbor’s shed and deposited her into an ambulance.

“The ride down to the hospital was quite a wild one,” Dr. Baker recalled.

Mallon was taken to an isolation ward at Willard Parker Hospital, and doctors tested her feces three times a week between March 20 and November 16, 1907. Salmonella enterica enterica serovar Typhi, the bacterium that causes typhoid, was found in nearly every sample. Soper visited Mallon at the hospital to explain why she had been confined for so long (and also to determine the possibility of securing her release).

“When you go to the toilet, the germs which grow within your body get upon your fingers, and when you handle food in cooking they get on the food. People who eat this food swallow the germs and get sick,” he told her. “If you would wash your hands after leaving the toilet and before cooking, there might be no trouble. You don’t keep your hands clean enough.”

Mallon, frustrated and lonely, wasn’t very receptive to his advice, and refused to give doctors permission to remove her gallbladder, which they suspected was the source of the germs. There’s a good chance that this was true, since recent scientific studies have shown that many asymptomatic typhoid carriers store typhoid bacteria in their gallbladders. When their gallbladders empty bile into their small intestines, some of the bacteria goes with it, and then gets excreted in their stool.

“No knife will be put upon me,” Mallon told the doctors who requested to remove it. “I’ve nothing the matter with my gallbladder.”

Soon after that meeting, Mallon was relocated to a bungalow near Riverside Hospital on New York's North Brother Island. Her quarters, originally built for the superintendent of nurses, were more spacious and more comfortable, but Mallon was still treated like a dangerous outcast, isolated from the rest of the island’s inhabitants.

Two years after her arrest on Park Avenue, Mallon sued the Department of Health, claiming that she had been imprisoned without due process of law—in fact, she hadn’t even been accused of a crime. Dr. William H. Park, the bacteriologist who had tested Mallon’s feces, took the stand to explain how Mallon—though seemingly healthy herself—was an asymptomatic typhoid carrier. Both sides presented compelling arguments, but the court simply didn’t want the responsibility of determining whether Mallon was fit to rejoin society.

They dismissed the case altogether, and a defeated Mallon returned to North Brother Island.

Life As a Culinary Renegade

In February 1910, Riverside Hospital finally decided to release Mallon on the condition that she promise not to work as a cook and “take such hygienic precautions as will protect those with whom she comes in contact, from infection.” She agreed to the terms and left the island.

What she didn’t do was keep her word. For the next five years, Mallon flitted from kitchen to kitchen in the area, introducing herself as “Marie Breshof” or “Mrs. Brown.” She cooked in a restaurant on Broadway, a hotel in Southampton, an inn in Huntington, and a sanatorium in New Jersey. Typhoid followed Mallon wherever she went, but she never stayed in one place long enough to rouse suspicion.

That is, until 1915, when Dr. Edward B. Cragin solicited Soper’s help in detecting the cause of a typhoid outbreak at New York’s Sloane Hospital for Women. More than 20 people had fallen ill, and the other servants had taken to calling the cook “Typhoid Mary”—a sobriquet that newspapers had used for Mallon during her solitary confinement.

After Soper positively identified the woman he knew to be Mary Mallon, the hospital alerted the Department of Health, and Mallon was whisked right back to North Brother Island. This time, she didn’t resist.

The Lonely Legacy of America’s Most Famous Asymptomatic Carrier

Mallon lived out her remaining 23 years in the lonely riverbank bungalow, processing tests in the hospital laboratory and making occasional sojourns to Queens to visit a family she was friendly with. According to Soper, “they were not particularly glad to see her.” She suffered a stroke in 1932, and passed away at age 69 on November 11, 1938. Only nine people attended her funeral at St. Luke’s Catholic Church in the Bronx.

In total, Mallon was officially responsible for infecting 53 people with typhoid—three of whom died—though there were likely many more that went unreported. While her commitment to good hygiene may have been lacking, the fact that she was so often treated like a pariah no doubt exacerbated her unwillingness to cooperate with doctors and other health officials. For many, including Mallon herself, it was simply difficult to believe that a perfectly healthy person who had never even been afflicted with a terrifying disease could somehow pass it on to dozens of others.

“It was to be Mary Mallon’s fate to clear away much of the mystery which surrounded the transmission of typhoid fever and to call attention to the fact that it was often persons rather than things who offered the proper explanation when the disease occurred in endemic, sporadic and epidemic form,” Soper wrote.

Mallon, however begrudgingly, charted a new path for scientists studying communicable diseases—and taught the rest of us just how important it is to wash our hands.