Biology of tomato flu.

Tomato flu is a disease characterized with flu-like symptoms and rashes spreading among children in India. The name is derived from the blisters resembling tomato. After the pandemic due to SARS-CoV-2 and its variants and monkey pox, the tomato flu virus is causing epidemic in India. So far, 100 children have been affected in Southern India particularly in two states, Kerala and Tamilnadu. The etiological agent is not identified yet by Indian health authorities. Experts believe that it could be a variant of hand, foot and mouth disease (HFMD) [1]. HFMD is most commonly caused by Coxsackie virus A16, A6 and Enterovirus 71. It occurs in children less than 5 years of age. Symptoms of HFMD starts with a prodromal phase of fever and flu like symptoms. Later it progresses to form erythematous spots on the tongue and buccal mucosa eventually blistering causing painful eating or drinking. It also forms rashes on the palms and soles that might be macular, papular or vesicular. Rarely, it can cause meningitis with symptoms of stiff neck, photophobia, projectile vomiting or meningoencephalitis that might result in paralysis [2].

The first case of tomato flu was identified in the Indian state of Kerala on 6th May 2022. So far, 82 cases have been reported from Kerala in children under 6 years and 26 cases from Tamil Nadu in children less than 9 years, both states located in South of India [3]. The symptoms of tomato flu are fatigue, nausea, vomiting, diarrhea, fever, dehydration, swelling of joints, body aches with rashes on hands and feet that eventually get bigger in size [1]. However, among the 100 children with tomato flu no other complications were reported. None of the children with tomato flu were admitted to the hospital and self-recovery was reported [4]. It is likely that the tomato flu reported in India might be caused by a variant of viral etiological agents of HFMD. On the other hand, it might be entirely a new viral etiological agent causing symptoms similar to HFMD or a sequela to other infections [1]. On the contrary, The British Medical Journal (BMJ) reported recently that the etiological agent for tomato flu is not a novel virus but Coxsackie virus A16. Swabs collected from two children who returned from India with tomato flu were positive for Coxsackie virus A16. The HFMD disease was mistaken for tomato flu since the blisters were larger than the usual size in India [5]. The tomato flu is highly contagious among children and therefore the children should be kept indoors and avoid sharing of clothes or toys. Efforts should be undertaken to collect more specimens from the infected children and sent for identification to confirm the etiological agent as reported by BMJ.

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