Streptococcus agalactiae (group B streptococcus, GBS) is an uncommon cause of bacterial meningitis in adults. We describe clinical characteristics, serotype distribution and outcome of adult GBS meningitis.

Patients aged 16 years or older with GBS cultured in cerebrospinal fluid included in two prospective nationwide cohort studies performed in the Netherlands between 1998–2002 and 2006–2017 were evaluated.

We identified 33 patients with GBS meningitis with a median age of 58 years of whom 22 were male (67%). The mean annual incidence was .16 per 1.000.000 adults. Ten patients (30%) had an immunocompromised state, which was due to alcoholism in 6 (18%) and diabetes mellitus in 4 (12%). Eleven patients (33%) had a distant focus of infection of whom 4 had endocarditis (13%). Seven patients (21%) died and 6 (18%) survivors had sequelae causing disability, including reduced vision and blindness due to endophthalmitis (n = 2). Twenty patients (61%) made a full recovery. Most common bacterial serotypes were serotype III (41%) and Ia (25%). Serotype V was associated with increased mortality (3 of 4 [75%] serotype V died vs. 4 of 28 [14%] other serotypes, P = .025).

GBS is a rare cause of meningitis in adults that more frequently occurs in patients with underlying comorbidities. Patients should be carefully evaluated for distant foci of infection. GBS serotype V is associated with poor outcome.