Listeria monocytogenes infections: Analysis of 41 patients.

OBJECTIVE

We describe and analyze Listeria-related demographics and clinical features to determine the predisposing conditions for severe infections.

METHODS

We performed a retrospective study using positive isolation of Listeria monocytogenes from blood, cerebrospinal fluid, and other organic fluids. Electronic health records were used to determine the epidemiological and clinical features of infections caused by L. monocytogenes. Mortality and sepsis were considered dependent variables in the statistical analyses.

RESULTS

We included 41 patients in an observation period of 15 years (2003-2018), with an annual incidence rate of 1.3 cases per 100,000 population. Three main population profiles were identified: newborns, pregnant women, and other adults (17.1%, 12.2%, and 82.9%, respectively). Neuroinvasive infection was present in 17 patients (41.5%). In both univariate and multivariate analyses, neurological infections, whether meningoencephalitis, rhombencephalitis, or brain abscesses, were the main risk factors for severe forms of Listeria-related infections (odds ratio 1.8, 95% CI 1.52-2.14, p=0.01). Malignancies, whether solid tumors or hematological neoplasms, immunosuppression, and chronic diseases were not related to either mortality or severe clinical syndromes.

CONCLUSION

Infections caused by L. monocytogenes were uncommon but could cause severe sepsis and mortality, especially in susceptible populations. Our study focused on neurological involvement and severe invasive forms of listeriosis. Neuroinvasive forms were the most important risk factors for severe illness but not for mortality.