To test the hypothesis that enterovirus meningitis (EM) is a frequent and self-limiting condition, the epidemiology of EM in adults was examined.
Using a prospective, nationwide, population-based database, all adults with EM confirmed by PCR of the CSF from 2015 to 2019 were included. Unfavorable outcome was defined as Glasgow Outcome Scale scores of 1–4 at discharge. Modified Poisson regression was used to compute adjusted relative risks (RRs).
A total of 419 cases of EM in 418 adults (46% female, median age 31 years [interquartile range (IQR) 27–35]) yielded an incidence of 1.80/100,000/year. Admission diagnoses included CNS infection 247/397 (62%), other neurologic conditions 89/397 (22%), and cerebrovascular diseases 33/397 (8%). Genotype was available for 271 cases, of which echovirus 30 accounted for 155 (57%). Patients presented with headache 412/415 (99%), history of fever 303/372 (81%), photophobia 292/379 (77%), and neck stiffness 159/407 (39%). Fever (≥38.0°C) was observed in 192/399 (48%) at admission. The median CSF leukocyte count was 130 106/L (range 0–2,100) with polymorphonuclear predominance (>50%) in 110/396 (28%). Cranial imaging preceded lumbar puncture in 127/417 (30%) and was associated with non-CNS infection admission diagnoses and delayed lumbar puncture (median 4.8 hours [IQR 3.4–7.9] vs 1.5 [IQR 0.8–2.8], p < 0.001). Unfavorable outcome occurred in 99/419 (24%) at discharge; more often in female patients (RR 2.30 [1.58–3.33]) and less frequent in echovirus 30 (RR 0.67 [0.46–1.00]) in adjusted analyses. Outcome remained unfavorable in 22/379 (6%) after 6 months.
EM is common among young, healthy adults. Although the long-term prognosis remains reassuring, a substantial proportion have moderate disability at discharge, especially female patients.