Hand, foot, and mouth disease (HFMD) in India: A review on clinical manifestations, molecular epidemiology, pathogenesis, and prevention

HFMD is a childhood viral disease initiated by enteroviruses (EVs). Symptoms are initiated with mild-to-moderate fever of short duration followed by oral and skin lesions. Skin lesions are papulovesicular which appears on palms/soles of feet, hands, knees, and elbows. Oral lesions appear as vesicles producing multiple small superficial ulcers. Disease is usually mild illness but sometimes progresses in severe form as meningitis, encephalitis, and polio-like paralysis. Etiological agents of the disease belong to Picornaviridae family. The causative viral agents are from genus human enterovirus (HEV) such as enterovirus-A 71 (EV-A71), coxsackievirus –A6 (CV-A6), CV-A10, CV-A16. Coxsackievirus A-16 (CV-A16) and enterovirus A-71 (EV-A71) are the major etiological agents of this disease, among children reported globally. In India, studies conducted on HFMD cases revealed CV-A16 as a major EV type and under circulation over a period of time. Molecular studies of different CV-A16 isolates and the viral kinetic studies conducted on organ tissues of experimental mouse model with complete VP1 gene sequencing revealed presence of B1c sub genotype which is currently in circulation. Genetic changes observed at nucleotide and amino acid level in vital organs of experimental infected mice model might predict some targets and can act as markers of virulence. Mice infected with CV-A16 strains revealed progressive pathological changes in mice organs. Major affected organs were to be as brain, heart, intestine, and skeletal muscles. The present review focuses on HFMD caused by CV-A16 with epidemiological, molecular, pathogenesis and need of antivirals against the disease.