Surveillance of Community-Acquired Listeria Monocytogenes Meningitis in Adults

Listeria monocytogenes is the third most frequent cause of bacterial meningitis. Amaya-Villar, et al. (2010) sought to know the incidence and risk factors associated with development of acute community-acquired Lm meningitis in adult patients and to evaluate the clinical features, management, and outcome in this prospective case series. Their research was published in BMC Infectious Diseases.

A descriptive, prospective, and multicentric study carried out in nine hospitals in the Spanish Network for Research in Infectious Diseases (REIPI) over a 39-month period. All adults patients admitted to the participating hospitals with the diagnosis of acute community-acquired bacterial meningitis (Ac-ABM) were included in this study. All these cases were diagnosed on the basis of a compatible clinical picture and a positive cerebrospinal fluid (CSF) culture or blood culture. The patients were followed up until death or discharge from hospital.

Two hundred and seventy-eight patients with Ac-ABM were included. Forty-six episodes of Lm meningitis were identified in 46 adult patients. In the multivariate analysis only age (OR 1.026; 95% CI 1.00-1.05; p=0.042), immunosupression (OR 2.520; 95% CI 1.05-6.00; p= 0.037), and CSF/blood glucose ratio (OR 39.42; 95% CI 4.01-387.50; p=0.002) were independently associated with a Lm meningitis. The classic triad of fever, neck stiffness and altered mental status was present in 21 (49 percent) patients, 32 percent had focal neurological findings at presentation, 12 percent presented cerebellum dysfunction, and 9% had seizures. Twenty-nine (68 percent) patients were immunocompromised. Empirical antimicrobial therapy was intravenous ampicillin for 34 (79 percent) of 43 patients, in 11 (32 percent) of them associated to aminoglycosides. Definitive ampicillin plus gentamicin therapy was significantly associated with unfavourable outcome (67% vs 28%; p=0.024) and a higher mortality (67% vs 32%; p=0.040).The mortality rate was 28 percent (12 of 43 patients) and 5 of 31 (16.1%) surviving patients developed adverse clinical outcome.

The researchers conclude that elderly or immunocompromised patients, and a higher CSF/blood glucose ratio in patients with Ac-ABM must alert clinicians about Lm aetiology. They also observed a high incidence of acute community-acquired Lm meningitis in adults and the addition of aminoglycosides to treatment should be avoid in order to improve the patients' outcome. Nevertheless, Amaya-Villar, et al. (2010) say that despite developments in intensive care and antimicrobial therapy, this entity is still a serious disease that carries high morbidity and mortality rates.

Reference: Amaya-Villar R, Garcia-Cabrera E, Sulleiro-Igual E, Fernandez-Viladrich P, Fontanals-Aymerich D, Catalan-Alonso P, Rodrigo-Gonzalo de Liria C, Coloma-Conde A, Grill-Diaz F, Guerrero-Espejo A, Pachon J and Prats-Pastor G. Three-year multicenter surveillance of community-acquired listeria monocytogenes meningitis in adults. BMC Infectious Diseases 2010, 10:324doi:10.1186/1471-2334-10-324