Work

Predominance of arboviruses in acute encephalitis and Guillain–Barré syndrome: Findings from a prospective cohort in Northeast Brazil

Year: 2026

Type: article

Abstract: OBJECTIVES: To characterize the clinical, epidemiological, and laboratory spectrum of acute viral-associated neurological syndromes in an arbovirus-endemic region of northeastern Brazil. METHODS: We conducted a prospective, hospital-based cohort (March 2020 to August 2025) including patients with suspected viral neurological syndromes. Systematic testing combined qRT-PCR and serology for arboviruses (CHIKV, DENV, ZIKV, OROV) with multiplex PCR for classical neurotropic viruses. Clinical, imaging, EEG, and ENMG data were collected using standardized electronic forms. Temporal and seasonal trends were analyzed using quasi-Poisson and cyclic generalized additive models. RESULTS: Among 132 patients, encephalitis (58%, 76/132) and Guillain-Barré syndrome (23%, 30/132) predominated. A viral etiology was identified in 42% (56/132), mostly arboviral. CHIKV (41%, 23/56) was the most frequent pathogen, followed by DENV (26%, 15/56) and OROV (11%, 6/56%), while HSV-1 was rare. GBS showed a significant upward trend and seasonal pattern, contrasting with stable encephalitis incidence. CSF, imaging, and electrophysiological findings were heterogeneous, reflecting complex diagnostic patterns. CONCLUSIONS: Arboviruses-particularly CHIKV, DENV, and emerging OROV-are leading causes of acute neurological syndromes in Brazil. The integration of multiplex viral panels and arboviral assays is essential to enhance diagnosis. Strengthened surveillance and molecular diagnostics are critical in regions with arboviral circulation.

Source: International Journal of Infectious Diseases

DOI: 10.1016/j.ijid.2026.108664