Epidemiological insights of hand, foot, and mouth disease: outbreak of Coxsackievirus A16 in Northern India

Background Hand-and-foot-and-mouth disease (HFMD) is an important epidemiological problem in Asia with global dissemination potential. The causative agents are Coxsackievirus A16 (CVA16), Enterovirus -71 (EV-A71), and related serogroups, which mainly affects children <10 years. Since 2003, India has been witnessing outbreaks of HFMD from different regions.Methods This study included HFMD suspected patients from two outbreak-affected villages and peripheral health facilitie sduring September and October, 2025. Molecular investigation was carried out using PCR or etiological detection. The causative agent was isolated using the Vero E6 cell line.Results Of total 38 suspected cases, 14 (36.8%) were positive for enterovirus by PCR. Sequence analysis of the 5’non-coding region (5’ NCR) confirmed CVA16 in all the subjects. Of PCR positive samples, majority were from outbreak-affected villages (78.6%), while 21.4% were from hospitals. Papulovesicular lesions localized to the elbows and knees, and Oral ulcers involving the oral mucosa, tongue, and hard palate were documented in 78.5% and 71.4% of infected patients respectively. The CVA16 isolation from vesicular swabs reconfirmed the causative etiology.Conclusion The study establishes CVA16 as the etiological agent of the HFMD outbreak. Further a substantial gap was found between clinical diagnosis and laboratory confirmation, which advocates the necessity of strengthening laboratory-based surveillance.