Predominance of arboviruses in acute encephalitis and Guillain–Barré syndrome: Findings from a prospective cohort in Northeast Brazil
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.
Authors
- Thiago Gonçalves Fukuda (ORCID: https://orcid.org/0000-0002-7718-4288)
- Felipe Oliveira Costa
- Maricélia Maia de Lima (ORCID: https://orcid.org/0000-0003-2320-4340)
- Mateus Santana do Rosário (ORCID: https://orcid.org/0000-0001-7404-6392)
- Sílvia Inês Sardi (ORCID: https://orcid.org/0000-0002-2002-8436)
- Pedro Antônio Pereira de Jesus (ORCID: https://orcid.org/0000-0003-1211-2272)
- Ricardo Khouri (ORCID: https://orcid.org/0000-0001-5664-4436)
- Ively Paixão Santos (ORCID: https://orcid.org/0009-0004-4807-0021)
- Isadora Cristina de Siqueira (ORCID: https://orcid.org/0000-0002-2520-4099)
- Alan Oliveira Duarte (ORCID: https://orcid.org/0000-0003-3810-7332)
- Gúbio Soares Campos (ORCID: https://orcid.org/0000-0002-1700-2462)
- Jamary Oliveira‐Filho (ORCID: https://orcid.org/0000-0003-1915-0423)
- Jesângeli de Sousa Dias (ORCID: https://orcid.org/0000-0002-8859-1989)
- Maria Paula de Souza Sampaio
- Mohammed Habib (ORCID: https://orcid.org/0000-0001-7756-7249)
- José Teles (ORCID: https://orcid.org/0000-0003-1373-8250)
- Tarsis Leonardo Almeida Farias
- Celia Silvany
- Bernardo Gratival Gouvea Costa
- Mariellen Santos de Jesus Souza (ORCID: https://orcid.org/0009-0008-5557-7882)
- Lorena Cunha Martins
- Luiza Vieira Luedy Trindade
- Adilson Junior Pinto Galvão
- Cássia Flávia Moreira Souza
- Janeusa Rita Leite Primo Chagas
- Pedro Sampaio Almeida Ramos Conceição
- Gabriela Farias Carreiro
- Marcia Carvalho Bessa
- Breno Pinheiro de Almeida Franco e Castro
- Tiago Gräf
- Gessica Almeida Vasconcelos
- Daniel Santana Farias
- Murilo Santos Souza
Institutions
- Universidade Federal da Bahia (BR)
- Instituto Federal da Bahia (BR)
- Universidade do Estado da Bahia (BR)
- Universidade Estadual de Feira de Santana (BR)
- Complexo Hospitalar Universitário Professor Edgard Santos (BR)
- Hospital Santa Izabel (BR)
- Hospital São Rafael (BR)
- Irkutsk Regional Clinical Hospital (RU)
- Fundação Carlos Chagas (BR)
- Fundação Oswaldo Cruz (BR)
Publication Details
- Journal
- International Journal of Infectious Diseases
- Published
- 2026-04-06
- DOI
- https://doi.org/10.1016/j.ijid.2026.108664
- Primary Topic
- Peripheral Neuropathies and Disorders
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Conselho Nacional de Desenvolvimento Científico e Tecnológico
- Fundação Oswaldo Cruz
- Instituto Serrapilheira