Chapter 12: Enteroviruses

Overview

Enteroviruses constitute a major subgroup of small, icosahedral, naked capsid positive-sense RNA viruses belonging to the family Picornaviridae (picornaviruses). Their name is derived from their ability to infect intestinal tract epithelial and lymphoid tissues and shed into the feces, but do not commonly cause gastrointestinal diseases. They are transmitted by the fecal–oral route and readily infect the intestinal tract and further spread to cause paralytic disease, mild aseptic meningitis, exanthems, myocarditis, pericarditis, and nonspecific febrile illness. These viruses include the polioviruses, coxsackieviruses, echoviruses, parechoviruses, and other agents that are simply designated as enteroviruses. There is another member of the picornavirus family called rhinoviruses that are not enteroviruses, because they are transmitted through respiratory route and cause common colds. Enterovirus infections can produce a great diversity of clinical disease. Some cause paralytic disease that may persist permanently (a typical feature of polioviruses), acute inflammation of the meninges with or without involvement of cerebral or spinal tissues, or sepsis-like illnesses in newborn infants. Inflammatory effects at other sites, such as the lungs, pleura, heart, and skin have been also observed, often without concomitant or preceding central nervous system (CNS) involvement. Occasionally, infections may result in chronic, active disease processes. For poliovirus, two types of vaccines, inactivated polio vaccine (IPV) and live attenuated oral polio vaccine (OPV), have been in use in preventing polio worldwide. Moreover, IPV is recommended for use in the United States.