What is 'fried rice syndrome,' and why is it killing people?

By Lisa Marie Basile | Fact-checked by Davi Sherman
Published November 2, 2023

Key Takeaways

  • “Fried rice syndrome” is a term popularized by social media; it refers to food poisoning caused by Bacillus cereus (BC) bacteria. 

  • Rarely, people have died from BC poisoning. For example, one recently trending social media video focuses on one 20-year-old who died after eating five-day-old pasta he’d left out at room temperature.

  • The term “fried rice syndrome” is a bit of a misnomer, though. Illness caused by BC stems from food that isn’t stored at proper temperatures and can include everything from grains and meat to cheese and pasta.

"Fried rice syndrome" is a somewhat silly (and vague) name that refers to an illness caused by Bacillus cereus (BC) bacteria. The topic started trending recently when an MD responded to a TikTok video about a 20-year-old man who died suddenly after eating five-day-old pasta.[]

In the video, user @drjoe_md—also known as Joe Whittington, MD, a board-certified emergency medicine physician—says that patients should not eat rice or pasta that’s been left at room temperature, unrefrigerated for more than two hours. Why? BC causes bacteria overgrowth that can, in rare cases, be fatal.

Erika Susky, MS, an Infection Control Practitioner at Unity Health in Toronto, says the etymology of the name derives from the Roman goddess of agriculture, Ceres. 

“Many, but not all, cases of food poisoning come from B. cereus after eating contaminated rice and grains,” Susky notes. “The illness is caused from ingesting toxins produced from the bacteria, which can replicate when the food is not stored at proper temperatures.” 

So, ‘fried rice syndrome’ is a bit of a misnomer, says Susky. “The bacteria can be in rice prepared in many different ways, in other grains, and in other foods as well ([like] milk, cheese, meats, spices, soups, baby food, fruits, and vegetables). What causes the illness is not the type of food that [is] eaten, but contamination [from] the toxin-producing bacterium B. cereus.”

The Journal of Clinical Microbiology found that, in the case cited in the video, the man ate spaghetti with tomato sauce, which had sat out for five days at room temperature. Prior to ingesting the pasta, he’d reheated it in the microwave. The journal reports that, within 30 minutes, the man complained of headache, abdominal pain, and nausea.[]

The authors write that he then “vomited profusely for several hours and at midnight had two episodes of watery diarrhea. He did not receive any medication and drank only water.” It was later found that he had died after going to bed, likely around 4 a.m.—approximately 10 hours after he’d eaten the food. 

There were a few key findings, the authors write, including “moderate centrolobular liver necrosis without inflammatory signs and discrete biliary stasis, significant vascular congestion of the lungs, probably due to acute cardiac insufficiency, significant necrosis from all layers of colon mucosa and submucosa alternating with better-preserved zones, and mixed intestinal flora but no evidence of invasive bacterial lesions.” Additionally, they found BC in two of five fecal swabs. While they assumed BC to be the culprit, they couldn’t definitively conclude so. 

“[T]he present case illustrates the severity of the emetic and diarrheal syndromes and the importance of adequate refrigeration of prepared food,” the authors write. 

Symptoms of B. Cereus

There are two clinical types of BC, including diarrhea syndrome and vomiting syndrome (emetic). StatPearls reports that emetic BC “has been associated with a few cases of liver failure and death in otherwise healthy people.” Furthermore, the journal reports that of the 63,400 episodes of BC illness annually in the United States, mortality related to the illness is “rare.”[][]

BC generally causes nausea, vomiting, diarrhea, and abdominal pain—and it usually acts very quickly, Susky says. Patients will get sick about 30 minutes after eating, although sickness can occur up to 15 hours later, she adds. 

Shirin Mazumder, MD, an infectious disease physician at Methodist Le Bonheur Healthcare in Memphis, TN, says that BC can also cause non-intestinal illness. “[This] affects organs outside of the gastrointestinal tract, including the eyes, respiratory tract, bones, wounds, and brain,” she says. But this is rare.[]

“The disease is usually brief and self-limiting,” Susky notes, “[but] it can be severe in higher-risk groups, like those with weakened immune systems.” 

Dr. Mazumder says treatment typically only requires hydration, sometimes intravenously, especially for patients with extreme nausea and diarrhea. Generally, she says, antibiotic therapy is not recommended.[] 

How can patients avoid B. Cereus? 

Susky says that foods are generally risky to human health when stored between 4 and 60 degrees Celsius (that’s 39.2 to 140 degrees Fahrenheit). “These are temperatures warm enough to allow the bacteria to replicate but not too hot as to kill the bacterium or inactivate a toxin within the food,” she says. If reheating food, it should be reheated to 74 degrees Celsius (or 165 degrees Fahrenheit), Susky adds. 

Patients should be encouraged to thoroughly cook their food and store it immediately in the fridge if it’s not consumed immediately afterward. Food should not be stored at room temperature or in warming trays for an extended period of time, Susky adds, as this allows the bacteria to replicate and produce more toxins. 

Carlos Fragoso, MS, a registered dietitian based in NYC and Founder of Nutrethos, says, “The number one rule of food temperature safety is timing: Cooked foods or raw meats, dairy, eggs, or fermented food that have been left out in the temperature danger zone for up to 2 hours need to be refrigerated or heated up to 165 degrees Fahrenheit for a minimum of 15 seconds.” Fragoso recommends that MDs and patients refer to the US Food and Drug Administration’s Refrigerator and Freezer Storage Chart for more information.

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