Listeria meningitis: case series in a tertiary level hospital and the usefulness of new microbiological diagnostic techniques

Abstract

Background: Listeria monocytogenes meningitis (MLM) is a serious entity with short-term complications. Polymerase chain reaction (PCR) can help to improve its diagnosis and prognosis. Aim: To know the characteristics of patients diagnosed with meningitis by L. monocytogenes in recent years, through different microbiological methods. Methods: Case series of adult patients admitted with MLM at the Hospital Clínico San Carlos of Madrid during twelve years (2009-2021). Epidemiological, clinical, microbiological, radiological and therapeutic variables were described. Results: Twelve patients with MLM were recorded (mean age 67.5 years, 75% male). Eight had a positive culture for L. monocytogenes. cerebrospinal fluid (CSF) PCR was positive in the two cases in which the test was performed. Treatment in all cases was ampicillin for 21 days. Complications were recorded in a quarter of the cases. One patient died. Conclusions: MLM is a rare and difficult to diagnose disease. In our series of cases, the two patients diagnosed by PCR had negative CSF culture results, and presented good evolution. PCR determination could allow a greater number of cases to be diagnosed earlier.