Epidemiology of Venezuelan haemorrhagic fever in Barinas state, Venezuela

Maria-Mercedes Garcia; Xacdiel Rodríguez; Santiago Jose Lopez; Jose Jose Reyes Dorante; Emilsa Jaqueline Aldana; Niyuris Elena Orduno; Aurora Lugo; Daniel Salazar; Nailyn Carvallo; Yismar Rivas; Cássia Fernanda Estofolete; Maurício Lacerda Nogueira; Carlos Lezcano-Coba; Josefrancisco Galué; Yelissa Juarez; Christl Ann Donnelly; Jose Narciso Franco; Jean‐Paul Carrera · medRxiv (2026) · DOI: 10.64898/2026.04.04.26348925

Resumen

Abstract Background Venezuelan haemorrhagic fever (VHF), caused by Guanarito virus (GTOV), is a zoonotic disease endemic to the western plains of Venezuela. Despite decades of recognition, its epidemiology and clinical profile remain poorly characterised. Methodology We analysed individual-level data from standardised case report forms submitted to the Venezuelan National Epidemiological Surveillance System between 2017 and 2024 for suspected VHF cases in Barinas, Apure, and Portuguesa. Demographic, clinical, and laboratory variables were examined to characterise temporal and geographical patterns and to define the clinical profile of VHF compared with endemic arboviral infections. Principal Findings Among 480 suspected cases, 72 (15.0%) were laboratory-confirmed GTOV infections. Confirmed cases occurred predominantly in men engaged in agricultural or service-related occupations, with the highest prevalence among individuals aged 46–90 years. A marked seasonal pattern was observed, with most cases occurring between September and January. The most frequently reported symptoms included headache, haemorrhage, sore throat, and diarrhoea. Compared with other endemic arboviral infections, GTOV was more strongly associated with headache, myalgia, sore throat, haemorrhage, and abdominal pain, delineating a distinct clinical phenotype relative to diseases caused by encephalitic alphaviruses, chikungunya virus, dengue virus, and Zika virus. The case fatality ratio among laboratory-confirmed cases was 36.1% (95% CI: 25.1–48.3). GTOV infection was independently associated with mortality (adjusted relative risk [aRR] 3.66; 95% CI 2.28–5.87; p < 0.001), underscoring its substantial clinical severity. Conclusion GTOV remains endemically transmitted in western Venezuela, disproportionately affecting older men engaged in agricultural and service-related occupations. Its seasonality and clinical phenotype, characterised by haemorrhage, sore throat, and gastrointestinal symptoms, highlight the need for clinical awareness and improved differential diagnosis, particularly in remote endemic settings with limited access to laboratory testing. Author Summary Venezuelan haemorrhagic fever is a serious disease with poorly understood epidemiology and clinical presentation and affects rural communities in western Venezuela. Although it has been recognised for decades, important gaps remain in understanding who is most at risk, how the disease presents, and why it leads to high mortality. In this study, we analysed national surveillance data collected between 2017 and 2024 to better describe its epidemiology and clinical features. We found that the disease mainly affects older men involved in agricultural and service-related work, with cases occurring more frequently in September and January. Patients commonly presented with headache, haemorrhage, sore throat, and gastrointestinal symptoms, forming a consistent set of clinical patterns. Infection was strongly associated with an increased risk of death. These findings highlight the need for earlier clinical recognition and improved diagnosis, particularly in resource-limited settings, and support the development of targeted public health actions to reduce preventable deaths in high-risk populations.

Instituciones: Universidad Peruana Cayetano Heredia