Community acquired meningitis in Santiago, Chile, 2011-2017

Background: In Chile, there is scarce information on the frequency of the causative microorganisms of community-acquired meningitis (CAM), which is relevant for the choice of empiric treatment. Aim: To describe the microbiology of CAM in patients over 15 years treated at a public hospital in Santiago (Chile). Methods: Retrospective review of positive cerebrospinal fluid cultures during 2011-2017. Clinical information of the included patients was collected. Cultures consi-dered as contamination and cases of post-surgical meningitis were excluded. Results: We identified 20 episodes of bacterial meningitis (BM) and six episodes of cryptococcal meningitis (CM) in 2720 cul-tures. The microorganisms identified in BM cases were Streptococcus pneumoniae (50%), Listeria monocytogenes (25%) and five other agents (25%). All patients with L. monocytogenes infection had at least one well-known risk factor for this infection. Four of the five cases of CM had HIV infection. Conclusion: Streptococcus pneumoniae was the most frequent causative microorganism of CAM in this series, followed by L. monocytogenes. Current recommendations for empiric CAM regimens adequately consider coverage for S. pneumoniae in all patients and for L. monocytogenes only in those with risk factors. Furthermore, it is relevant to consider CM in cases involving immu-nocompromised patients.