What Is the Tomato Flu Virus?

Earlier this summer, a team of scientists reported a “new virus” in India that affected more than 100 children across three states. In the wake of COVID-19, monkeypox and the re-emergence of polio, the tomato flu outbreak stoked fear of yet another communicable disease that threatened the public’s safety.

Dubbed the “tomato flu” due to the red blisters and rash that develop on the skin, the scientists reported a new, rare viral infection first detected on May 6 in 82 children in the state of Kerala, India. Shortly afterward, 26 additional cases were found in two nearby states of Tamil Nadu and Odisha. They reported their findings in an August 2022 paper in The Lancet Respiratory Medicine, but experts believe it didn’t present enough actionable data.

A New Virus

“The first step for all of these emerging virus infections is to isolate the virus. And that’s a big chunk of it,” says Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine and co-director of the Texas Children’s Hospital Center for Vaccine Development. “The problem is it’s hard to treat if you don’t know what you’re treating. If you knew the class of virus it was, then you could move a lot faster.”

Scientists in the United Kingdom eventually sequenced the genetic material of the virus from two infected children and have since identified the culprit behind the outbreak: coxsackievirus A16, a known enterovirus. Enteroviruses are very common viruses that typically only cause mild symptoms similar to the common cold.

Although the cases of tomato flu are still under investigation, many health experts believe the mystery behind the virus is solved. Much like the slew of COVID-19 variants and other viral strains that evolved through mutations, tomato flu is not new. Instead, it was simply an offshoot of the common coxsackievirus A16 that presented with an atypical symptom: the red, blood-filled blisters.

“We’re not 100% sure what the cause of tomato flu is, but the most likely scenario is that it’s a coxsackievirus,” says Dr. Edward Ryan, director of Global Infectious Diseases at Massachusetts General Hospital in Boston. “I think it’s a reasonable assumption.”

Coxsackievirus A16, which was first identified in the 1950s in South Africa, is more widely known to cause hand, foot and mouth disease, which circulates primarily among young children. Not to be confused with foot and mouth disease — also referred to as hoof and mouth disease — found in animals, hand, foot and mouth disease is highly contagious but not life-threatening.

Hand, foot and mouth disease usually affects “young children at the age of five who come home from daycare or school or they pick it up from their cousins,” says Ryan, who also serves as professor of medicine at Harvard Medical School and professor of immunology and infectious diseases at Harvard T.H. Chan School of Public Health. “It’s a virus that gives kids fevers and irritability … for about three to five days, and they can get dehydrated because it hurts to swallow (from) the lesions in the mouth.”

While all signs point to tomato flu being a misnomer, there are still more questions than answers about the illness and why there seem to be more cases and more viruses and variants popping up.

“We’re going to see more and more of these situations,” Hotez says. “As the confluence of urbanization, deforestation and climate change all start to meld, these are the new 21st-century forces that are driving emerging infections.”

Although no reports of tomato flu have been reported in the United States, health experts are aware and prepared to address any cases of tomato flu as hand, mouth and foot disease.

[See: 9 Myths and Misconceptions About the Flu Vaccine.]

Symptoms of Tomato Flu

The hallmark sign of tomato flu is the red, tomato-like vesicles — small, fluid-filled blisters — that appear on the skin, which is what gives it its moniker.

“For reasons we don’t understand, in this syndrome, they bleed a bit into the lesions,” Ryan says. “They become sort of cherry red and can get big, (whereas) normal vesicles are more grayish or yellowish.”

Other symptoms associated with tomato flu are similar to hand, foot and mouth disease, including:


— Fatigue.


— Body aches.


Symptoms in children are typically mild. According to the Centers for Disease Control and Prevention, children can return to daycare or school as long as they do not have a fever, mouth sores or lethargy. But if parents are still on the fence, the CDC recommends talking with their child’s pediatrician to discuss options.

[See: Signs of a Cold You Shouldn’t Ignore.]


Coxsackievirus A16 is a highly contagious virus that can be passed from one person to another through bodily secretions, such as respiratory droplets, fluid from blisters or scabs and fecal matter.

The CDC notes that individuals are most contagious during the first week of their infection when the viral load is at its highest. However, the virus can still spread for days or weeks even after symptoms have resolved or if the individual is asymptomatic.

People are most likely to catch the virus by:

— Coming in contact with respiratory droplets from an infected person.

— Touching or close contact, such as kissing, hugging or sharing eating utensils.

— Handling fecal matter from an infected person.

— Touching objects and surfaces that an infected person came in contact with, then touching your eyes, nose or mouth.

“Usually, the things that are most infectious are bodily secretions and things that were touched by bodily secretions,” Ryan explains. “That’s why it often spreads through the household, especially if you have a little child who’s crying and irritable and maybe has diarrhea.”


Currently, there are no specific drugs to treat tomato flu. But because it’s a self-limiting disease, which is an illness that resolves on its own without treatment, the infection will clear up within a few days.

In the meantime, supportive care can be provided to treat the symptoms of tomato flu. For example, nonprescription medications — such as acetaminophen (Tylenol) and ibuprofen (Advil) — can be used to reduce fever and body aches.

However, the main concern is dehydration. Because the painful sores in the mouth make it difficult for children to swallow, parents and caretakers should encourage them to drink as much as they can to stay hydrated.

[Read: Here’s What You Should Eat to Fight Off Colds and the Flu.]


Health experts say tomato flu is not cause for alarm based on current knowledge, but given how common hand, foot and mouth disease is — especially during summer and fall — it’s better to be safe than sorry.

There is no vaccine for hand, foot and mouth disease, but there are measures to reduce your risk of catching it.

“It really comes down to typical coxsackie(virus) precautions,” Ryan says, including what experts call “contact precautions.”

In short, the same safety guidelines we learned from COVID-19 and monkeypox apply:

Wash your hands with soap and water frequently for at least 20 seconds, especially after handling diapers, using the toilet, blowing your nose or coming in contact with an infected person.

— Use alcohol-based hand sanitizer in between hand washings.

Clean and disinfect surfaces and items that are frequently touched.

— Avoid touching your eyes, nose and mouth.

— Avoid close contact with an infected person.

Although tomato flu is most likely a new symptom of an old virus, it’s not out of the realm of possibility for a new virus to emerge.

“It’s just part of our reality as being a human animal on this planet that emerging pathogens, whatever they are — viruses, bacteria, etc. — are part of life,” Ryan says.

More from U.S. News

What Are the Symptoms of Coronavirus?

Myths About Your Immune System

13 Tips for a Healthy Fall

What Is the Tomato Flu Virus? originally appeared on usnews.com

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