The WEST Study: A Retrospective and Multicentric Study on the Impact of Steroid Therapy in West Nile Encephalitis

Background: The use of steroid therapy in potentially life-threatening neuroinvasive forms of West Nile infection (WNND) is controversial. The aim of this study is to assess the efficacy of steroid therapy in reducing intrahospital mortality, length of stay, and neurological sequelae at discharge. Methods: This was a multicenter, retrospective, observational study conducted in 5 hospitals in Northern Italy, headed by the Fondazione IRCSS Policlinico San Matteo (Pavia). We extracted all patient data with WNND diagnoses, comparing patients who received steroid treatment with patients who did not receive steroid treatment between January 2014 and January 2022. Comparisons between the 2 groups were performed using chi-square tests for categorical variables and Mann-Whitney tests for non-normal continuous data, and a generalized linear model for the binomial family was carried out. Results: Data from 65 WNND patients were extracted. Among these patients, 33 (50.7%) received steroid therapy at any point during their hospitalization. Receiving steroid therapy did not significantly reduce intrahospital mortality (odds ratio [OR], 1.70; 95% CI, 0.3-13.8; P = .89) or neurological sequelae at discharge (OR, 0.53; 95% CI, 0.16-1.76; P = .47). Conclusions: Steroid treatment is currently used on a single-case basis in severe WNND. More prospective data are needed to demonstrate a protective effect on mortality and neurological sequelae.