Enterovirus surveillance--United States, 2002-2004.

Enteroviruses are common viruses associated with diverse clinical syndromes, ranging from minor febrile illness to severe, potentially fatal conditions (e.g., aseptic meningitis, encephalitis, paralysis, myocarditis, and neonatal enteroviral sepsis). A total of 68 enterovirus serotypes are recognized, including 65 nonpolio enteroviruses. Individual serotypes have different temporal patterns of circulation and can be associated with different clinical manifestations. This report describes trends in reported enterovirus infections in the United States during 2002-2004, including widespread circulation of two serotypes, echovirus 9 and echovirus 30, commonly associated with aseptic meningitis outbreaks. Monitoring circulating enteroviruses helped identify these two serotypes as primary causes of aseptic meningitis outbreaks in 2003. Increased state laboratory participation and timely reporting by all laboratories to CDC would further increase the public health utility of enterovirus surveillance.