Identification of a novel Indian clade of Coxsackievirus A16 in Hand, Foot and Mouth disease outbreak in 2022

Aim: In 2022, there was a severe hand, foot and mouth disease (HFMD) outbreak in India. This study focuses on the identification and molecular characterization of the causative agent. Methods: 51 suspected HFMD patients were examined. Viral RNA from HFMD-positive patients' vesicular extracts were sequenced. Phylogenetic analysis was carried out for genotype and mutation identification in current outbreak strains. Results: Phylogenetic analysis revealed a novel Indian clade of CVA16 belonging to genotype B1c. Two consistent mutations, R41H in the VP3 protein and G492T in the conserved 5′-UTR region, were found only in novel clade strains. Conclusion: The present study highlights the possibility and significance of the aforementioned mutations in increasing the ability of CVA16 to spread among adults.