“Tomato flu” is a misnomer: HFMD due to Coxsackie A16 likely cause of outbreak in India

An Aug. 17 letter in Lancet Respiratory Medicine titled “Tomato Flu Outbreak in India” speculated on causes of an outbreak of febrile rash with red lesions in approximately 108 young children in India (Kerala then Tamil Nadu and Odisha) since May 2022.  

Of note, the three authors stated the following in the letter’s opening paragraph:

“… a new virus known as tomato flu, or tomato fever, has emerged in India in the state of Kerala in children younger than 5 years. The rare viral infection is in an endemic state and is considered non-life-threatening …”

The authors did not present data for “a new virus” nor what they meant by “the rare viral infection is in an endemic state,” if indeed it was a new virus.

On Aug. 19, viral sequencing by the U.K. Health Security Agency in Colindale, London, demonstrated Coxsackie A16 from skin lesions in two children returning from Kerala to the U.K. in May 2022, as reported in The Pediatric Infectious Disease Journal by Tang et al. in an article titled “Kerala Tomato Flu —  A Manifestation of Hand, Foot and Mouth Disease.”  

They reported that “Phylogenetic analysis showed that the ‘Kerala tomato flu’ partial CA16 sequences shared a most common recent ancestor with a clade from China (2011-2014) (Figure S1, Supplemental Digital Content 1, http://links.lww.com/INF/E793).”

My review of this one-page supplement found this statement: “A single sequence from France (2006, purple) is shown as part of the China clade.”

While keeping an open mind to new data that may appear later, at this point there is no evidence of a new virus or disease. The term “tomato flu” is a misnomer that should no longer be used because both HFMD and its enteroviral causes, such as Coxsackie A16, are well known.