Cerebrospinal fluid (CSF) microscopy may be normal or suggest bacterial meningitis in a substantial minority of adults with echovirus meningitis. In 2001, there was an outbreak of echovirus meningitis in north west England. Researchers from Liverpool and Dublin prospectively studied 40 patients admitted between March and August to an infectious disease unit with a probable meningitis diagnosis. Half the cases were male, with a median age of 28 (range 16-51). Fifteen of 38 (39.5 per cent) were smokers and 20 of 24 (83.3 per cent) had close contact with children. The median duration of symptoms was 1.1 days (range 0.25-7). Symptoms included headache (100 per cent), photophobia (87.5 per cent) and nausea (67.5 per cent). Severity ranged from minimal signs to those consistent with meningoencephalitis.