Coxsackievirus is a virus that belongs to a family of nonenveloped, linear, positive-sense ssRNA viruses, Picornaviridae and the genus Enterovirus, which also includes poliovirus and echovirus.oxsackievirus is a virus that belongs to a family of nonenveloped, linear, positive-sense ssRNA viruses, Picornaviridae and the genus Enterovirus, which also includes poliovirus and echovirus.