Mary Mallon was a great cook. So great that she’d made a comfortable life for herself in the kitchens of the rich after arriving in New York City as a penniless teenager from Ireland.

She was especially known for her peach ice cream.

Later, she became known as “Typhoid Mary,” a moniker recalled over the weekend as young people flooded bars to celebrate St. Patrick’s Day, and a Nevada school board candidate wondered why she shouldn’t eat at her favorite Red Robin restaurant amid the novel coronavirus pandemic.

In 1906, it wasn’t a chain restaurant that caught the attention of George Soper but Mary’s peach ice cream recipe. A doctor and “sanitary engineer,” he had been hired by a wealthy family to investigate a typhoid outbreak in the summer home they rented out in Oyster Bay. They were afraid that unless they found the source of outbreak, no one would ever rent it again.

Soper was a diligent investigator. He suspected the outbreak had been caused not by a contaminated water supply, as was often the case with typhoid, but by contaminated food. Most of what the renter’s staff prepared that summer would have been safe to eat, because most of it was cooked at high temperatures.

But not peach ice cream.

Soper tracked Mallon’s job history back years, doing what epidemiologists today would call “contact tracing.” He found eight former employers; seven had experienced typhoid outbreaks while Mallon was in their service. One of them had even given her a bonus when she stayed late to nurse the sick, according to Judith Walzer Leavitt in “Typhoid Mary: Captive to the Public’s Health.”

Soper later said he was aware of research in Europe indicating that typhoid could have “asymptomatic carriers” — people walking around shedding germs who never appeared to get sick. He suspected Mallon might be one of them. All in all, Soper claimed she had caused two dozen illnesses and one death.

In March 1907, Soper found the Park Avenue house where Mallon was then employed and demanded that she give him samples of her feces, urine and blood. She threw him out of the house. Next, he went to health department officials with his theory. Eventually, she was dragged kicking and cursing from the home by police and forced to give specimens at a hospital.

She was full of the typhoid bacteria.

Soper soon announced his findings at a physicians conference, and she became world famous. The media dubbed her “Typhoid Mary,” depicting her as a heartless serial poisoner flipping flapjacks full of germs. No matter that about a thousand New Yorkers got typhoid every year. Most of those were poor people with bad water supplies. The few dozen people that Mallon “attacked” were rich.

Mallon refused to believe what the doctors told her and declined their offers to remove her gallbladder (thought at the time to be the source of her typhoid shedding). So she was declared a menace to society and sent to live in isolation on North Brother Island, between the South Bronx and Rikers Island in the East River.

She was there for three years before her lawyers successfully petitioned for her release, under the condition that she give up cooking as a profession.

And for a while she did. She got a job in a laundry, where the soap kept everyone safe and the pay, well, it stank.

In 1915, Mallon was caught cooking under a different name at a maternity hospital. This time, she was blamed for another two dozen cases of typhoid with two deaths.

“ ’TYPHOID MARY’ HAS REAPPEARED: Human Culture Tube, Herself Immune, Spreads the Disease Wherever She Goes,” a New York Times headline announced.

She was taken into custody and returned to her isolation bungalow on North Brother Island, where she remained for the rest of her life. She died in 1938 at 69.

It is unclear how many people with covid-19, the disease caused by the novel coronavirus, caught it from asymptomatic carriers, according to The Washington Post’s William Wan, which is part of the reason health officials have suggested that even low-risk, asymptomatic people practice “social distancing” in the coming weeks and months.

Given the highly infectious nature of the coronavirus and how exponential growth works, it is possible an asymptomatic carrier could infect more people than “Typhoid Mary” ever did.

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