Molecular Epidemiology of Western Equine Encephalitis Virus, South America, 2023–2024
Western equine encephalitis virus (WEEV) is a mosquitoborne virus that reemerged in December 2023 in Argentina and Uruguay, causing a major outbreak. We investigated the outbreak using epidemiologic, entomological, and genomic analyses, focusing on WEEV circulation near the Argentina‒Uruguay border in Rio Grande do Sul state, Brazil. During November 2023‒April 2024, the outbreak in Argentina and Uruguay resulted in 217 human cases, 12 of which were fatal, and 2,548 equine cases. We determined cases on the basis of laboratory and clinical epidemiologic criteria. We characterized 3 fatal equine cases caused by a novel WEEV lineage identified through a nearly complete coding sequence analysis, which we propose as lineage C. Our findings highlight the importance of continued surveillance and equine vaccination to control future WEEV outbreaks in South America.
Authors
- Ingra Morales Claro (ORCID: https://orcid.org/0000-0001-8637-2910)
- Vilar Ricardo Gewehr
- Scott C. Weaver (ORCID: https://orcid.org/0000-0001-8016-8556)
- Gabriel Luz Wallau (ORCID: https://orcid.org/0000-0002-1419-5713)
- Ana Cláudia Franco (ORCID: https://orcid.org/0000-0001-7747-5125)
- Richard Steiner Salvato (ORCID: https://orcid.org/0000-0002-5701-9437)
- Aline Alves Scarpellini Campos (ORCID: https://orcid.org/0000-0002-1731-3527)
- Xinyi Hua (ORCID: https://orcid.org/0000-0001-9368-1228)
- Fernanda Marques de Souza Godinho (ORCID: https://orcid.org/0000-0002-2211-192X)
- William Marciel de Souza (ORCID: https://orcid.org/0000-0002-0025-8293)
- Amanda Pellenz Ruivo (ORCID: https://orcid.org/0009-0006-2955-7701)
- Rosana Huff (ORCID: https://orcid.org/0009-0008-3021-3759)
- Carla Rosane Rodenbusch (ORCID: https://orcid.org/0000-0003-0911-5966)
- Cristiane Krause Santin (ORCID: https://orcid.org/0000-0002-9683-678X)
- Jáder da Cruz Cardoso (ORCID: https://orcid.org/0000-0002-1214-1084)
- Laura Bauermann (ORCID: https://orcid.org/0000-0002-5022-792X)
- Thales Bermann
- Tainá Machado Selayaran
- Juciane Bonella (ORCID: https://orcid.org/0009-0006-2238-2830)
- José Carlos Ferreira (ORCID: https://orcid.org/0000-0002-4315-9359)
- Franciellen Machado dos Santos
- Paola Morais
- Carolina Franceschina
- Darlan S. Candido
Publication Details
- Journal
- Emerging infectious diseases
- Published
- 2024-08-23
- DOI
- https://doi.org/10.3201/eid3009.240530
- Citations
- 24
- Primary Topic
- Mosquito-borne diseases and control
- Type
- article
- Field-Weighted Citation Impact
- 13.03