| Title: |
Could commercial poultry farms contribute to H5N1 endemicity in Bangladesh? |
| Authors: |
Duault, Hélène; Pinotti, Francesco; Hasan, Mahmudul; Mahmud, Rashed; Nath, Chandan; Uddin, Helal; Akter, Sazeda; Butt, Saira; Carnegie, Lorcan; Jenkins-Lynton, Josh; Banyard, Ash; Tomley, Fiona; Blake, Damer; Hill, Sarah; Conan, Anne; Syndicus, Ivo; Biswas, Paritosh; Samad, Mohammed, Abuds; Hoque, Ahasanul; Fournié, Guillaume |
| Contributors: |
Unité Mixte de Recherche d'Épidémiologie des maladies Animales et zoonotiques (UMR EPIA); VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE); Bangladesh Livestock Research Institute (BLRI); Chattogram Veterinary and Animal Sciences University; Royal Veterinary College (RVC); University of London London; Animal and Plant Health Agency Addlestone, UK (APHA); Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad); Epidemics - The Journal on Infectious Disease Dynamics30 November – 3 December 2025 |
| Source: |
EPIDEMICS 10: 10th International Conference on Infectious Disease Dynamics ; https://hal.inrae.fr/hal-05489053 ; EPIDEMICS 10: 10th International Conference on Infectious Disease Dynamics, Nov 2025, San Diego, United States. ; https://www.elsevier.com/events/conferences/all/international-conference-on-infectious-disease-dynamics#0-about |
| Publisher Information: |
CCSD |
| Publication Year: |
2025 |
| Collection: |
Institut National de la Recherche Agronomique: ProdINRA |
| Subject Terms: |
Endemicity; Avian influenza; poultry; Modeling; [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie |
| Subject Geographic: |
San Diego; United States |
| Description: |
International audience ; Background & Aim. H5N1 highly pathogenic avian influenza poses a major threat to poultry production and global health. In Bangladesh, where the virus is endemic, live bird markets (LBMs) – through which most poultry is traded – constitute a key hotspot of viral circulation. Despite the predominance of broiler chickens in national meat production and the absence of vaccination in this sector, H5N1 outbreaks in broiler farms are rarely notified, and virus detection during cross-sectional studies is uncommon. This, combined with the much higher infection prevalence in marketed ducks, has led to the assumption that broiler farms play a limited role in viral spread. They are therefore ignored by control programs in Bangladesh as well as other H5N1-endemic countries. We hypothesize, however, that this pattern reflects under-reporting, and that a combination of maternally derived immunity and early sale of flocks, healthy or diseased, allows silent viral circulation.Methods & Results. We combined observational studies, qualitative interviews, mechanistic and phylodynamic modelling. We investigated 310 chickens farms in Dhaka and Chattogram divisions seeking veterinary support due to abnormal mortality between 2022-23. H5N1 was detected in 10% of them. Longitudinal sampling of 70 broiler flocks detected H5N1 infections in 6% of these late in their production cycles. A stochastic meta-population model fitted via an MCMC approach indicated that virus transmission could be sustained. Due to delayed infection following temporary maternal immunity, outbreaks occurred after birds reached marketable age—limiting detection and facilitating sale. Interviews confirmed that sick flocks were sold outside formal live bird marketing channels, limiting economic losses. A time-scaled phylogeny of 25 viral genomes from affected farms and nearby LBMs showed that farm sequences clustered separately, supporting the hypothesis of sustained farm-to-farm transmission.Implications. Our findings challenge the ... |
| Document Type: |
conference object; still image |
| Language: |
English |
| Availability: |
https://hal.inrae.fr/hal-05489053; https://hal.inrae.fr/hal-05489053v1/document; https://hal.inrae.fr/hal-05489053v1/file/Poster_Epidemics_251120.pdf |
| Rights: |
https://creativecommons.org/licenses/by/4.0/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.E4A97DD6 |
| Database: |
BASE |