Several media outlets have called attention this week to an unfamiliar virus that's been spreading among children in India -- the "tomato flu." But scientists say its unfamiliarity is up for debate.
Tomato flu, which got its name from the red, inflamed blisters that appear on infected patients, has been reported in more than 82 kids in Kerala, as well as an additional 26 children in two neighboring states, Tamil Nadu and Odisha, according to the .
Reports of the non-fatal, yet contagious, disease quickly caught on in the headlines, with news outlets reporting a rare, "new" viral infection. However, there are no data to confirm that tomato flu is in fact a new virus -- or even a flu at all.
Instead, preliminary evidence suggests it may be just another clinical presentation of an infection that's quite common in kids: hand, foot, and mouth disease.
"This is not a new disease, and is not a new virus," said Daniel Lucey, MD, MPH, clinical professor of medicine at the Dartmouth Geisel School of Medicine in New Hampshire. "That's my take at this point."
Cases of tomato flu were first reported in Kerala in early May and have mostly spread among kids under 5 years old. There were about 100 cases as of July 26 reported in the region, some in kids as old as 9 years.
Little data describing testing or gene sequencing have emerged out of India since the start of the outbreak. However, last week a case report was published in the , presenting the results of biological testing in two patients.
The case report analyzed a 13-month-old girl and her 5-year-old brother, both of whom were suspected to have tomato flu. The children developed vesicular rashes on their hands and legs about a week after returning from a month-long trip to Kerala with their family.
Two days after the kids first experienced a rash, the girl developed oral lesions, while the boy's rash healed. Neither of the kids had a fever or any other flu-like symptoms.
The children received PCR tests for enteroviruses, and the girl was tested for monkeypox due to the appearance of her lesions. These samples were then sent to labs for gene sequencing. The researchers determined that the illness was caused by the coxsackievirus A16 -- a pathogen that causes hand, foot, and mouth disease.
"This virus is not new," said Julian Tang, MD, PhD, of University Hospitals of Leicester in England, lead author of the case report. "I don't think this is something to be alarmed about."
Hand, foot, and mouth disease is typically mild, although it can lead to severe consequences in rare cases. There are no vaccines or antivirals available for the disease, Tang noted.
Lucey, who is also an expert from the Infectious Diseases Society of America, said it led him to believe two things: that this is very likely not a new virus, nor a new variant of a pathogen that's already out there. He pointed to a included in the case report, which showed the relation of coxsackievirus A16 to a previous outbreak in China in 2011 to 2014, as well as an outbreak in France that occurred in 2006.
In a time when reports of new emerging viruses and outbreaks seem common, stories about infectious diseases can garner a lot of attention, Lucey said. But in this case, that attention has led to many misconceptions about tomato flu, he added, starting with its name, which he : "there are no tomatoes."
Many recent news reports about tomato flu sparked a correspondence recently published in . The letter stated that the "new" tomato flu virus "gained its name on the basis of the eruption of red and painful blisters throughout the body that gradually enlarge to the size of a tomato."
The letter, written by Vivek Chavda, of L.M. College of Pharmacy in Gujarat, India, and colleagues, said that the symptoms of tomato flu can look similar to COVID-19, including fever, fatigue, and body aches. The authors raised the possibility that tomato flu could be a "new variant of the viral hand, foot, and mouth disease" or an after-effect of chikungunya or dengue fever, both of which are mosquito-borne illnesses.
However, some experts the correspondence, stating that it made implications about the virus without data. No evidence of clinical presentations of the virus or virological test results were included in the paper. Chavda did not respond to a request for comment from 鶹ý as of press time.
Lucey said he would like to see biological testing and genetic sequencing from at least 10 more patients involved in the India outbreak, which is likely to be forthcoming. Until there are more data, however, he said hand, foot, and mouth disease is a probable cause of the outbreak.
"I think it's important to address concerns," Lucey said. "But for right now, I don't think there's any new virus, new disease or new clinical manifestation."