Its one of the most common forms of food poisoning in the world.
Salmonella — a stubborn bacterium known for its spread through contaminated food, water and even pets — is responsible for roughly 1.35 million infections in the U.S. each year. It leads the country in food poisoning-related hospitalizations and deaths, according to the Centers for Disease Control and Prevention.
Most recently, a salmonella outbreak tied to a California egg producer sickened at least 79 people, as of June 6. It also triggered a recall of 1.7 million dozen eggs that may have been contaminated.
Despite its fishy name, salmonella has no connection to the underwater creature salmon. Rather, the story behind the bacterium is one of disputed credit between two American researchers. It's also linked to one of the most famous cases in medical history about the balance between public health and individual freedoms.
Here's a look at the origins behind the bacterium's name.
Where did 'salmonella' come from?
The bacterium is named after Daniel E. Salmon, an American veterinary pathologist from the late 19th century, according to the Food and Drug Administration.
While the bacterium bears his name, there is some debate over how much credit Salmon should receive over his laboratory assistant Theobald Smith, who many believe was the one to isolate the microorganism from sick pigs in 1885. At the time, the bacterium was referred to as "hog-cholera bacillus" because it was identified while researching the cause behind hog cholera.
Salmon and Smith clashed over credit several times, according to a biography on Salmon. Still, their collaboration led to major advances in public health, including research that would help pave the way for the production of the polio vaccine.
In 1900, French-Argentinian bacteriologist Joseph Leon Lignières who was studying the pathogen proposed that the species of bacterium be named "salmonella" in honor of Salmon.
" It's very common for species of all kinds and bacteria and basically anything in the scientific world to be named after its discoverers," said Jess Zafarris, an author of etymology books who writes about word origins.
Zafarris added that it was also common to add the Latin suffix "ella" when naming bacteria and algae. For example, "Chlorella" combines the Greek word "chloro," meaning green, with the suffix to describe green algae. Similarly, the bacterium "leigionella" was named after an outbreak that occurred at an American Legion convention.
Salmonella's appearance over the centuries and 'Typhoid Mary'
While salmonella's name was coined in the 20th century, evidence suggests the bacterium itself has been infecting humans for centuries.
In 2017, scientists determined that a deadly form of the bacteria may have played a role in the collapse of the Aztec Empire over 500 years ago. A year later, researchers detected a strain of salmonella in an 800-year-old human skeleton from Norway.
One of the earliest and most famous cases of a salmonella outbreak began after a woman named Mary Mallon moved to the U.S. from Ireland in the 1880s. Mallon was an asymptomatic carrier of salmonella typhi, which causes typhoid fever, and she unknowingly infected several families while working as a cook for a wealthy New York banker.
George Soper, a sanitary expert, investigated the cases, similar to what we know today as contact tracing. It led him to believe that Mallon was an asymptomatic carrier of typhoid fever. To be sure, at one point, Soper showed up to Mallon's work place and asked for samples of her blood, urine and stool, according to Susan Campbell Bartoletti, author of "Terrible Typhoid Mary."
"She grabs a carving fork and she swears and she attacks him and he fled," Bartoletti told NPR in 2020.
By 1907, some 3,000 New Yorkers had been infected with salmonella typhi and Mallon was considered the key source.
Soper ultimately convinced city officials that Mallon was a public health threat, leading to her forced quarantine for over two years. After her release, new infections were traced back to Mallon, and she was permanently quarantined until her death over 20 years later.
The case of Mallon and Soper remains a powerful example in medical history of the complexities between protecting public health and preserving individual freedoms.
"When George Soper appeared in that kitchen and accused her, she was insulted. And she didn't want to lose her work, her only means of employment," Bartoletti said. "Maybe he needed to explain it to her differently. Maybe he shouldn't have gone in expecting her to understand right away what he was talking about. It frightened her."
Why is it important today?
More than a century after the major outbreak in New York, salmonella remains one of the leading causes of foodborne illness — second only to norovirus, according to the Centers for Disease Control and Prevention.
Nearly a quarter of salmonella infections are caused by eating contaminated chicken and turkey. But there have also been outbreaks linked to cucumbers, cantaloupe, pet turtles and most recently, eggs.
These outbreaks come amid massive cuts by the Trump administration to the three federal agencies responsible for food safety oversight. That includes the Food and Drug Administration, the Department of Agriculture, and the Centers for Disease Control and Prevention.
"Our federal food safety system is teetering on the brink of a collapse," Sarah Sorscher, a policy expert at the Center for Science in the Public Interest, told NPR last month.
In statements to NPR, the FDA and USDA said last month that the recent changes will not alter their commitment to food safety. The CDC also previously said it "remains prepared to respond to, and work with states on those outbreaks."
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