Highly Pathogenic Avian Influenza A (H5N1) Virus Outbreak in Ecuador in 2022–2024

• Published in: Current infectious disease reports 2024-12, Vol.26 (12), p.245-253
• Main Authors: Bruno, Alfredo, de Mora, Doménica, Olmedo, Maritza, Garcés, Jimmy, Vélez, Alberto, Alfaro-Núñez, Alonzo, Garcia-Bereguiain, Miguel Angel
• Format: Article
• Language: English
• Subjects: Aquatic mammals; Avian flu; Birds; Dairy cattle; Epidemics; Genomes; Health surveillance; Infectious Diseases; Medicine; Medicine & Public Health; Migratory birds; Outbreaks; Pandemics; Phylogenetics; Poultry; Prevention; Prevention programs; Section Editors; Topical Collection on Tropical; Travel and Emerging Infections; Travel and Emerging Infections (LH Chen and F Norman; Tropical; Wildlife
• ISSN: 1523-3847; 1534-3146
• DOI: 10.1007/s11908-024-00849-5

Purpose of Review Highly pathogenic avian flu viruses (HPAIVs) are considered one of the main candidates for the next pandemic due to its current trend to improve infectivity towards mammal species. The ongoing influenza A H5N1 clade 2.3.4.4b outbreak affecting the Americas has spread from North America to South America since 2022 and have recently reached Antarctica. Besides an unprecedented impact in poultry industry, it has also spread through migratory bird to aquatic mammals causing massive death events in South America rising concern about a potential mammal-to-mammal transmission. Moreover, H5N1 human cases in Ecuador and Chile, and outbreaks in dairy cattle in the USA with cattle-to-human transmission cases made the Pan America Health Organization to declare an epidemiological alert for H5N1 in the Americas in June 2024. Recent Findings We reviewed the current situation of H5N1 epidemic in Ecuador where farm and backyard poultry outbreaks, a human case and several events of infection in wild bird species have been notified to the World Health Organization and the World Organization for Animal Health from 2022 to 2024. A detailed description of the H5N1 epidemiological scenario is provided and a phylogenetic analysis for the eight H5N1 sequences available for Ecuador is done where multiple entries of H5N1 strains are described. Summary HPAIVs sentinel surveillance assisted by genome surveillance is fundamental for a successful avian flu control and prevention program. We found some potential gaps in H5N1 surveillance in Ecuador considering that poultry outbreaks are geographically segregated from wild bird outbreaks; this fact points out the need of a more intense sentinel surveillance including poultry, wildlife and humans under a One Health approach. Moreover, H5N1 genomic surveillance must be improved as only 8 genome sequences have been uploaded to public repositories in almost two years of avian flu epidemic. HPAIVs genomic surveillance is crucial to follow up the dynamics and evolution of those viruses to assist an effective avian flu control and prevention program in Ecuador.