ENTEROVIRUS INFECTIONS: ETIOLOGIC, EPIDEMIOLOGIC AND CLINICAL ASPECTS

The term enteroviruses was introduced in 1957 to bring together in one large family the polioviruses, Coxsackie A and B and echoviruses, all agents for which the human alimentary tract is the natural habitat. At present more than 60 distinct members are recognized: three polioviruses, 24 Coxsackie A, six Coxsackie B and 30 echoviruses. The list of new members, particularly in the echo-group, grows regularly. The viruses are frequently widely disseminated in the summer and fall of the year, circulating chiefly among young children, causing both apparent and inapparent infection. The enteroviruses are responsible for a wide spectrum of clinical manifestations, including non-specific febrile illness, sometimes with rash, aseptic meningitis, paralytic disease, respiratory infections, pericarditis and myocarditis. There is considerable overlap in biologic behavior, and the same syndrome can be induced by many different agents. In a few instances the clinical pattern is distinct enough to suggest the group of agents involved. Thus, herpangina is associated with the Coxsackie A viruses and epidemic myalgia (devil's grip) with the Coxsackie B group. Paralytic disease is caused primarily by the polioviruses, but recently it has been found that other members, particularly the Coxsackie B viruses and Coxsackie A7 can also cause "paralytic poliomyelitis."The ultimate potential of enteroviruses in terms of central nervous system disease and other manifestations is unpredictable. Great variety in terms of clinical and epidemiologic behavior of known and "new" viruses has been the pattern in the past, and is likely to continue.