[Infections by Listeria monocytogenes].

Background: Listeria monocytogenes infections have been poorly characterized in Chile.

Aim: To evaluate clinical manifestations and risk factors associated to a fatal outcome in a series of patients.

Methods: retrospective analysis of cases from 1991 to 2012.

Results: Twenty three cases were identified, including 2 diagnosed after prolonged hospitalization (8.7%) with an average age of 68.4 years (range 44-90). Known predisposing factors were age > 65 years (60.9%), diabetes mellitus (40.9%), and immunosuppression (27.3%). Most cases presented after 2003 (70%). No cases associated with neonates, pregnancy or HIV infections were recorded. Patients presented with central nervous system (CNS) infection (39%), including 8 cases of meningitis and one of rhomboencephalitis; bacteremia (43.5%), including one case with endocarditis; abscesses (8.7%); and other infections (spontaneous bacterial peritonitis and pneumonia; 8.7%). Risky food consumption was found in 80% of those asked about it. Predominant clinical manifestations were fever (90.9%), and confusion (63.6%). CNS infections were associated to headache (OR 21, p < 0.05), nausea and vomiting (OR 50, p < 0.01). Only 45.5% received initial appropriate empirical therapy and 36.4% a synergistic combination. Eight patients died (34.8%), this outcome was associated to bacteremia (OR 8.25; IC95 1.2-59 p < 0.05).

Conclusions: L. monocytogenes infections appear to be increasing in Chile, causing infections in different sites, attacking vulnerable patients, and have a high case-fatality ratio, especially among those with bacteremia.