Outbreak of aseptic meningitis among adults in southern Taiwan.

A total of 38 adult cases of aseptic meningitis were diagnosed based on clinical manifestations as well as examination of cerebrospinal fluid at Kaohsiung Veterans General Hospital in 2001. The majority (31 cases, 82%) of cases occurred between June and August, and most (33 cases, 87%) of them aged from 18 to 35 years (median age, 25 years). The male-to-female ratio was 2.16:1. Common clinical presentations included headache, fever, nausea or vomiting, and symptoms of common cold. On initial cerebrospinal fluid examination, white cell counts were above 500 cells/mm3 in 7 (18%) cases, and neutrophils predominated in 10 (28%) of 36 cases. The cerebrospinal fluid protein concentration was below 100 mg/dL in 29 (77%) of 38 cases, and hypoglycorrhachia (cerebrospinal fluid/serum glucose ratio <0.5) was seen in 9 (24%) cases. Enterovirus as a definite etiology was confirmed by isolation from cerebrospinal fluid in 17 (45%) of 38 cases and was the presumptive etiology by isolation from the stool or throat swab in 2 (5%) cases. Of the 19 cases with positive viral isolation, echovirus serotype 30 accounted for the majority (15 cases, 79%), followed by echovirus serotype 6 (3 cases, 16%), with one (5%) case undetermined. The viral isolation rate from cerebrospinal fluid correlated to the day of cerebrospinal fluid sampling after disease onset (chi2 = 12.05, p = 0.007). All patients were discharged uneventfully without receiving antibiotic therapy.