Oropouche virus attack rate in an urban setting outside the Amazon Basin: findings from a post-outbreak seroprevalence survey.
15 affiliations
- 1Faculdade de Medicina, Centro Universitário Christus, Rua João Adolfo Gurgel, 133, Fortaleza, Ceará, 60192-345, Brazil.
- 2Escola de Saúde Pública do Ceará, Av. Antônio Justa, 3161, Fortaleza, Ceará, 60165-090, Brazil.
- 3Faculdade de Medicina, Universidade Federal do Ceará, Rua Alexandre Baraúna, 949, Fortaleza, Ceará, 60430-160, Brazil.
- 4Secretaria de Saúde do Ceará, Av. Almirante Barroso, 600, Fortaleza, Ceará, 60060-440, Brazil.
- 5Curso de Medicina, Universidade de Fortaleza, Av. Washington Soares, 1321, Fortaleza, Ceará, 60811-905, Brazil.
- 6Faculdade de Medicina, São Leopoldo Mandic, Campinas, Rua Dr. José Rocha Junqueira, 13, Campinas, São Paulo, 13045-755, Brazil.
- 7Department of Epidemiology, Harvard TH Chan School of Public Health, 665 Huntington Avenue, Kresge Building, Boston, MA, 02115, USA.
- 8Laboratory of Studies in Agriculture and Agrometeorology, Federal University of Rio Grande do Sul, Porto Alegre, 91501-900, Brazil.
- 9Secretaria Municipal de Saúde de Baturité, Praça Valdemar Falcão, Baturité, Ceará, 62760-000, Brazil.
- 10Núcleo de Vigilância de Vírus Emergentes, Reemergentes ou Negligenciados (ViVER/EDTA), Instituto Leônidas e Maria Deane, Fiocruz, Rua Terezina, 476, Manaus, Amazonas, 69057-070, Brazil.
- 11Department of Virology 1, National Institute of Infectious Diseases, Japan Institute for Health Security, Shinjuku-ku, Tokyo, 162-8655, Japan.
- 12Faculdade de Ciência e Tecnologia em Saúde, Campus Ceilândia, Universidade de Brasília (UnB), Ceilândia Sul Campus Universitário, Brasília, Distrito Federal, 72220-275, Brazil.
- 13Núcleo de Medicina Tropical, Faculdade de Medicina, UnB, Universidade de Brasília Campus Universitário Darcy Ribeiro, s/n, Brasília, Distrito Federal, 70910-900, Brazil.
- 14Institute for Health Assessment and Translation for Chronic and Neglected Diseases of High Relevance - IATS Care, Rua Ramiro Barcelos, 2350, Prédio 21, Belo Horizonte, Minas Gerais, 90035-903, Brazil.
- 15Department of Global Health and Population, Harvard TH Chan School of Public Health, 665 Huntington Avenue, Building 1, Room 1102A, Boston, MA, 02115, USA.
Abstract
Background
Oropouche virus (OROV) is transmitted by the biting midge Culicoides paraensis. Historically, it was restricted to small outbreaks in the Amazon region. Since 2023, genomic reassortment and human-environment interactions facilitated its geographic expansion, including into urban areas. We estimate the OROV attack rate and identify factors associated with infection in an urban area outside the Amazon.Methods
A randomised cross-sectional serosurvey in the urban area of Baturité, Brazil. Households were selected using stratified probability sampling proportional to census tract population; one resident per household was randomly chosen. Participants completed a questionnaire, and serum samples were tested for OROV IgM using MAC-ELISA. Associations were estimated using prevalence ratios (PR) with 95% confidence intervals from Poisson regression with robust variance. Spatial clustering of seropositives was assessed using kernel density and nearest-neighbours.Findings
Of 392 participants, 212 were seropositive (54·0%). Most infections were asymptomatic/oligosymptomatic (72·6%-154/212). Living near rivers (PR = 1·80; 95% CI: 1·20-2·50) and working from home (PR = 1·70; 95% CI: 1·30-2·30) were associated with higher prevalence of infection. Clustering of seropositivity was found in census tracts close to cultivated and forested areas, and in central urban neighbourhoods.Interpretation
We show large-scale urban OROV transmission, with attack rates exceeding 50%. The high proportion of infections among low mobility individuals suggests peridomestic transmission and vector adaptation to urban microenvironments. Results highlight the need to incorporate OROV into routine surveillance, outbreak preparedness, and differential diagnoses of acute febrile illnesses.Funding
Health Surveillance Secretariat/Brazilian Ministry of Health, and Japan International Cooperation Agency.
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BibTeX
@article{cavalcanti2026oropouche,
title = {{Oropouche virus attack rate in an urban setting outside the Amazon Basin: findings from a post-outbreak seroprevalence survey.}},
author = {Luciano Pamplona de Góes Cavalcanti and Francisca Kalline de Almeida Barreto and Antonio Silva Lima Neto and Rebeca de Souza Oliveira and Higor da Silva Monteiro and Carlos Henrique Alencar and André Ricardo Ribas Freitas and Carlos Garcia Filho and Ana Maria Peixoto Cabral Maia and Caroline Gulen Tangoren and Macleidi Varnier and Fernanda Kézia de Sousa Silva and Eulália Maria Loureiro Maia Campelo and Tânia Mara Silva Coelho and Lauro Vieira Perdigão Neto and Maria Auxiliadora Bessa Santos and Maria Fatima Ferreira de Oliveira and Wanderson Souza Marques and Felipe Gomes Naveca and Matilde Del Carmen Contreras Mejía and Ana Beatriz Vieira Muniz and Maria Julia Pessoa Brandão and Chang-Kweng Lim and Shoko Nishiyama and Hiromi Abe-Chayama and Hideki Ebihara and Wildo Navegantes de Araújo and Marcia C Castro},
journal = {Lancet regional health. Americas},
year = {2026},
month = oct,
doi = {10.1016/j.lana.2026.101662},
url = {https://europepmc.org/article/MED/42921383},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Oropouche virus attack rate in an urban setting outside the Amazon Basin: findings from a post-outbreak seroprevalence survey.
AU - Luciano Pamplona de Góes Cavalcanti
AU - Francisca Kalline de Almeida Barreto
AU - Antonio Silva Lima Neto
AU - Rebeca de Souza Oliveira
AU - Higor da Silva Monteiro
AU - Carlos Henrique Alencar
AU - André Ricardo Ribas Freitas
AU - Carlos Garcia Filho
AU - Ana Maria Peixoto Cabral Maia
AU - Caroline Gulen Tangoren
AU - Macleidi Varnier
AU - Fernanda Kézia de Sousa Silva
AU - Eulália Maria Loureiro Maia Campelo
AU - Tânia Mara Silva Coelho
AU - Lauro Vieira Perdigão Neto
AU - Maria Auxiliadora Bessa Santos
AU - Maria Fatima Ferreira de Oliveira
AU - Wanderson Souza Marques
AU - Felipe Gomes Naveca
AU - Matilde Del Carmen Contreras Mejía
AU - Ana Beatriz Vieira Muniz
AU - Maria Julia Pessoa Brandão
AU - Chang-Kweng Lim
AU - Shoko Nishiyama
AU - Hiromi Abe-Chayama
AU - Hideki Ebihara
AU - Wildo Navegantes de Araújo
AU - Marcia C Castro
PY - 2026
DA - 2026/10/14
JO - Lancet regional health. Americas
DO - 10.1016/j.lana.2026.101662
UR - https://europepmc.org/article/MED/42921383
AB - Background Oropouche virus (OROV) is transmitted by the biting midge Culicoides paraensis. Historically, it was restricted to small outbreaks in the Amazon region. Since 2023, genomic reassortment and human-environment interactions facilitated its geographic expansion, including into urban areas. We estimate the OROV attack rate and identify factors associated with infection in an urban area outside the Amazon.Methods A randomised cross-sectional serosurvey in the urban area of Baturité, Brazil. Households were selected using stratified probability sampling proportional to census tract population; one resident per household was randomly chosen. Participants completed a questionnaire, and serum samples were tested for OROV IgM using MAC-ELISA. Associations were estimated using prevalence ratios (PR) with 95% confidence intervals from Poisson regression with robust variance. Spatial clustering of seropositives was assessed using kernel density and nearest-neighbours.Findings Of 392 participants, 212 were seropositive (54·0%). Most infections were asymptomatic/oligosymptomatic (72·6%-154/212). Living near rivers (PR = 1·80; 95% CI: 1·20-2·50) and working from home (PR = 1·70; 95% CI: 1·30-2·30) were associated with higher prevalence of infection. Clustering of seropositivity was found in census tracts close to cultivated and forested areas, and in central urban neighbourhoods.Interpretation We show large-scale urban OROV transmission, with attack rates exceeding 50%. The high proportion of infections among low mobility individuals suggests peridomestic transmission and vector adaptation to urban microenvironments. Results highlight the need to incorporate OROV into routine surveillance, outbreak preparedness, and differential diagnoses of acute febrile illnesses.Funding Health Surveillance Secretariat/Brazilian Ministry of Health, and Japan International Cooperation Agency.
SN - 2667-193X
ER -