Outbreaks of aseptic meningitis associated with echoviruses 9 and 30 and preliminary surveillance reports on enterovirus activity--United States, 2003.

Aseptic or viral meningitis is the most common type of meningitis and is associated with an estimated 26,000--42,000 hospitalizations each year in the United States. Enteroviruses are the most common cause of aseptic meningitis. Echovirus 9 (E9) and echovirus 30 (E30) have been associated frequently with outbreaks of aseptic meningitis. During March 2003, several state public health departments noted increased reports of aseptic meningitis and, as of August 7, seven states (Arizona, California, Georgia, Idaho, Oregon, South Carolina, and Texas) had reported outbreaks associated with either E9 or E30. This report summarizes the epidemiologic features of the aseptic meningitis outbreaks in five states (Arizona, California, Georgia, Idaho, and South Carolina) and provides an overview of enterovirus activity in the United States during January 1--August 7. Enteroviruses, E9 and E30 in particular, should be considered in the differential diagnosis of persons with aseptic meningitis.