Coxsackievirus A16 is a serotype of Enterovirus A and one of the most frequent causes of hand, foot and mouth disease (HFMD) worldwide. It is a non enveloped icosahedral virus about 30 nm in diameter with a single stranded positive sense RNA genome. The virus replicates in the mucosal epithelium of the oropharynx and intestine and spreads primarily through fecal–oral contact, respiratory droplets and contact with fluid from vesicles. Infection mostly affects children under five years of age but adults can also be infected. Illness is generally mild with fever, sore throat and vesicular rash.
Structure, lifecycle and epidemiology
Coxsackievirus A16 belongs to the Picornaviridae family. Its genome encodes a polyprotein that is cleaved into four structural proteins (VP1‑VP4) and non‑structural proteins needed for replication. The virion is stable over a range of pH values, allowing survival in the environment and passage through the stomach. Following entry via the mouth or nasal passages, the virus multiplies in the upper respiratory and intestinal mucosa and then disseminates through the bloodstream to skin and oral mucosa, where it induces characteristic vesicles. CV‑A16 circulates worldwide and exhibits seasonal peaks in summer and early autumn. Outbreaks are common in childcare centres due to close contact among children. Unlike enterovirus A71, CV‑A16 rarely causes severe neurological complications. There are no specific antiviral treatments or vaccines; management focuses on relieving fever and pain while the infection runs its course. Preventive measures include proper hand washing, disinfection of toys and avoidance of close contact with infected individuals.
Clinical manifestations and public health importance
Hand, foot and mouth disease caused by CV‑A16 typically begins with low‑grade fever, malaise and sore throat, followed by the development of small, tender vesicles on the tongue, gums, palate and inside of the cheeks. Within a day or two, a papulovesicular rash appears on the palms and soles, sometimes extending to the buttocks. The lesions may be painful but usually resolve within seven to ten days. Complications are uncommon but can include aseptic meningitis or onychomadesis (nail shedding). Outbreaks in Asia have occasionally involved hundreds of cases, prompting public health campaigns to promote hygiene and temporary closure of affected childcare facilities. Adults with CV‑A16 infection may present with more severe systemic symptoms but still recover fully. Distinguishing HFMD from animal foot‑and‑mouth disease is important; the latter affects livestock and is unrelated. Coxsackievirus A16 remains the prototypical cause of hand, foot and mouth disease and is responsible for large seasonal outbreaks in young children. Although the illness is usually self limited, public health measures aimed at hygiene and education help reduce transmission. Related Terms: Hand‑foot‑and‑mouth disease, Coxsackievirus A6, Enterovirus A71, Coxsackievirus A10, Coxsackievirus B4