The so-called tomato flu that is spreading among children in Kerala, India, is probably caused by foot and mouth disease, a common childhood illness that is usually mild.
August 25, 2022
In recent weeks, there have been reports of a disease dubbed “tomato flu” affecting a small number of children in Kerala, India. It appears that tomato flu is just a new and misleading name for a common and usually mild childhood illness known as foot and mouth disease. It is also possible that some cases are related to mosquito-borne chikungunya and dengue fever.
What do we know about tomato flu?
A little. There have been various reports of cases in Kerala in the media, but so far only one report appears to have been released of test results on children with what looks like tomato flu.
The two children had just returned to the UK from Kerala where they were playing with another child who, according to the mother, had just had “tomato flu”. A week after returning, a 13-month-old girl and a 5-year-old brother developed a rash of small, fluid-filled blisters without any other symptoms.
Julian Tang of the University of Leicester and colleagues found that children were infected with the Coxsackievirus, which is the cause of hand disease, foot-and-mouth disease, or HFMD. In other words, tomato flu might just be HFMD.
“The hand, foot and mouth have been around for centuries,” Tan says. “I was stunned to see this storm in the media.”
Doctors in India came to the same conclusion. “Tomato fever is a misleading colloquial name for hand, foot and mouth disease,” says Rajiv Jayadevan of the Indian Medical Association.
So it’s still not a new virus?
No, it’s not. Indeed, a letter published in Lancet described it as a “new virus”. However, this letter contained no evidence and has been criticized by some other experts.
“[It] he seems to be ignoring the facts and the body of information already known about the disease, and even tries to paint a disturbing picture and sensationalize the issue.” Vinod Skaria tweeted. at the Institute of Genomics and Integrative Biology in India.
However, it’s possible that some children in Kerala who were said to have had tomato flu actually had dengue or chikungunya, Tan says. These mosquito-borne diseases cause rashes, fever, and joint pain, and some children with tomato flu are said to have had these symptoms. However, dengue and chikungunya do not cause fluid-filled blisters, the symptom that led to the term “tomato flu.”
And it has nothing to do with the flu or tomatoes?
No. The Coxsackieviruses that cause HFMD belong to a group of viruses called enteroviruses that are not related to influenza viruses and have nothing to do with plants.
Why did some doctors in Kerala think it was a new disease?
It’s not clear. However, rashes caused by a single virus can be very variable, Tan says. Moreover, in recent decades, new variants of enteroviruses have emerged in China and have spread throughout the world. According to him, these new lines can manifest themselves in different ways. One, called Coxsaxie A6, sometimes causes large blisters about a centimeter in diameter.
“This is very worrisome for parents,” Tan says. “Perhaps some doctors in Kerala are not familiar with these new manifestations and have raised the alarm about something that is only developing.”
“If you don’t work in this area and follow it closely, you won’t be aware of this evolution of this disease and the rapid departure from the classic form that we saw twenty or thirty years ago.”
However, Tang was surprised to find Coxsackie A16, which is one of the oldest strains, in two children in the UK. This is still one of the most common causes of HFMD.
Both A6 and A16 are circulating in India and there has been a reported spike in HFMD infections after children returned to school following the lifting of coronavirus-related restrictions.
Are there any treatments for HFMD?
No, there is no cure, but the vast majority of children recover quickly without any long-term effects. Some children develop serious complications such as encephalitis (inflammation of the brain) and acute flaccid paralysis (weakness of the arms or legs), but this is rare.
“The most important thing is that the children get well,” Tan says. “Very few get seriously ill, very few get scars.”
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