Molecular surveillance confirms absence of avian influenza virus type A in Ecuadorian poultry: A retrospective reverse transcription quantitative polymerase chain reaction study from April 2023 to June 2024

Vet World Vol.18 August-2025 Article - 12

Research Article

Veterinary World, 18(8): 2272-2286

https://doi.org/10.14202/vetworld.2025.2272-2286

Byron Puga-Torres¹

, Hugo Navarrete²

, and David de la Torre³

1. Departamento de Biología Molecular, Laboratorio de Biología y Genética Molecular (LABIGEN), Quito, Ecuador.

2. Centro de Estudios Aplicados en Química (CESAQ), Pontificia Universidad Católica del Ecuador, Quito, Ecuador.

3. Institutional Review Boards, Institute for Research in Biological Sciences, Quito, Ecuador.

Background and Aim: Avian influenza (AI) is a highly contagious zoonotic disease affecting birds and, occasionally, humans. Ecuador confirmed its first case of AI in late 2022, resulting in significant avian mortality and economic losses. In response, the Ecuadorian government implemented a mandatory control program emphasizing pre-vaccination diagnostics using reverse transcription quantitative polymerase chain reaction (RT-qPCR) or enzyme-linked immunosorbent assay. This study aimed to confirm the absence of AI virus type A in poultry across six major provinces of Ecuador following the 2022 outbreak, as part of the national eradication and vaccination campaign.

Materials and Methods: A cross-sectional, retrospective molecular surveillance study was conducted from April 2023 to June 2024. A total of 343 pooled tracheal swab samples were collected from poultry farms in six provinces (Chimborazo, Cotopaxi, El Oro, Pastaza, Pichincha, and Tungurahua), covering over 1 million birds. The samples were analyzed using real-time RT-qPCR, targeting the M gene, and subtype-specific genes (H5, H7, and H7N9).

Results: All 343 pooled samples (100%) tested negative for AI virus type A, suggesting an absence of active viral circulation during the study period. The implementation of pre-vaccination testing and biosecurity protocols contributed to this outcome.

Conclusion: The study confirms that AI virus type A was not circulating in Ecuadorian poultry during the surveillance period. These findings underscore the effectiveness of collaborative efforts among government, industry, and laboratories. Ongoing molecular surveillance remains essential for early detection and prevention of future outbreaks, reinforcing Ecuador’s commitment to One Health principles.

Keywords: Avian influenza, Ecuador, H5N1, highly pathogenic avian influenza, One Health, Poultry, Reverse transcription quantitative polymerase chain reaction, surveillance.

How to cite this article: Puga-Torres B, Navarrete H, and de la Torre D (2025). Molecular surveillance confirms absence of avian influenza virus type A in Ecuadorian poultry: A retrospective reverse transcription quantitative polymerase chain reaction study from April 2023 to June 2024, Veterinary World, 18(8): 2287-2294.

Received: 15-04-2025 Accepted: 17-07-2025 Published online: 09-08-2025

Corresponding author: Hugo Navarrete E-mail: hnavarrete@puce.edu.ec

DOI: 10.14202/vetworld.2025.2272-2286

Copyright: Puga-Torres, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.