Merkel cell polyomavirus infection in childhood: current advances and perspectives.

Merkel cell polyomavirus (MCPyV) is a newly discovered human small, non-enveloped, double-stranded DNA virus, which was classified into the Polyomaviridae family. MCPyV is acquired in early childhood through close contact involving respiratory tract secretions and causes a widespread, previously unrecognised, asymptomatic infection in both immunocompetent children and adults. To date, several researchers have established that MCPyV is the potential causative agent of Merkel cell carcinoma, a relatively rare but life-threatening skin cancer of neuroendocrine origin. In our review, we present current data on the presence of MCPyV DNA in children and address the possible role that the respiratory tract plays in the route of viral transmission. Future studies are required to fully elucidate the potential implications of MCPyV infection in children.