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Showing posts with the label poultry

Highly pathogenic avian #influenza #management in high-density #poultry #farming areas

By G.M.
Abstract The continuous spread of highly pathogenic avian influenza H5 viruses poses significant challenges, particularly in regions with high poultry farm densities where conventional control measures are less effective. Using phylogeographic and phylodynamic tools , we analysed virus spread in Southwestern France in 2020-21, a region with recurrent outbreaks. Following a single introduction, the virus spread regionally, mostly affecting duck farms , peaking in mid-December with a velocity of 27.8 km/week and an effective reproduction number between farms (Re) of 3.8, suggesting the virus can spread beyond current control radii. Transmission declined after late December following preventive culling. Farm infectiousness was estimated around 9 days. Duck farm density was the main driver of virus spread and we identified farm density and proximity thresholds required to maintain effective control (Re < 1). These findings offer actionable guidance to support regional biosecurity and to...
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#Denmark - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

By G.M.
On 31 March 2025 a clinical suspicion was reported to the Danish Veterinary and Food Administration. The affected poultry holding consists of 24 hens. On 1 April 2025 highly pathogenic avian influenza subtype H5N1 was confirmed by the national reference laboratory. A 3 km protection zone and a 10 km surveillance zone has been established. The culling was completed on 1 April 2025. Carcasses will be disposed of by rendering. Source: WOAH,  https://wahis.woah.org/#/in-review/6392 ____
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Promising effects of #duck #vaccination against highly pathogenic avian #influenza, #France 2023-24

By G.M.
Abstract The ongoing panzootic of highly pathogenic avian influenza (HPAI) H5 clade 2.3.4.4b has caused widespread poultry mortality and raised concerns about zoonotic pandemics and wildlife conservation . France recently adopted a preventive vaccination strategy , vaccinating domestic ducks with inactivated and mRNA vaccines . This study evaluates the impact of this campaign on reducing HPAI H5 outbreaks. Using predictive modeling based on previous outbreak data, the expected number of outbreaks in 2023-24 without vaccination was significantly higher than the observed cases, indicating a 95.9% reduction attributable to vaccination . These findings suggest that vaccination effectively mitigated the HPAI H5 outbreak in France. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2024.08.28.609837v3 ____
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Different #genetic #determinants for high #virulence, #transmission and #replication of high pathogenicity #H7N7 avian #influenza virus in #turkeys and #chickens

By G.M.
Abstract High pathogenicity (HP) avian influenza viruses (AIV) generally evolve from low pathogenicity (LP) precursors after transmission from wild birds to chickens (Gallus gallus domesticus) and turkeys (Meleagris gallopavo), causing severe economic losses worldwide. Turkeys are more susceptible to AIV infection than chickens and are considered potential bridging hosts that facilitate the emergence of HPAIV . Beyond the polybasic cleavage site (pCS) in hemagglutinin (HA), little is known about other virulence determinants of HPAIV in these species. In 2015, HPAIV H7N7 and its LP ancestor were isolated from the same chicken farm, which differed by 16 nonsynonymous mutations across all eight gene segments, in addition to the pCS. Here we identify the genetic determinants, including the pCS, that contributed to the HPAIV H7N7 virulence, transmission, replication, and tissue distribution in chickens and turkeys. Notably, the non-structural (NS1) or matrix (M) proteins ’ encoding segments...
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Analyses of #phylogenetics, natural #selection, and #protein structure of clade 2.3.4.4b #H5N1 #Influenza A reveal that recent viral lineages have evolved promiscuity ...

By G.M.
Abstract H5N1 influenza has been circulating in birds from Eurasia and Africa for more than 146 years , but human infection has been sporadic. H5N1 (clade 2.3.4.4b) has recently infected hundreds of species of wild and domestic birds and mammals in North America . Furthermore, as of February 26, 2025, H5N1 has infected 70 humans in the United States , and one infection proved lethal . Furthermore, in attempts to control H5N1 in the United States, 10s of millions of egg-laying chickens have died or been culled . These efforts have led to very high egg prices in the United States. We have developed an analytical bioinformatics and genomics workflow to understand better how H5N1 is circulating in North America and adapting to new host species . Our workflow consists of: 1) Phylogenetic analyses of large viral sequence datasets to identify subclades of viral lineages causing the current outbreaks in humans and farm animals and closely related viral background lineages. 2) Next, we transfer...
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#USA - High pathogenicity avian #influenza #H7N9 viruses (#poultry) (Inf. with) - Immediate notification

By G.M.
Highly pathogenic avian influenza (HPAI) H7N9 of North American wild bird lineage was detected in a commercial broiler breeder chicken flock in Mississippi . Depopulation of the affected flock is in progress. The USDA Animal and Plant Health Inspection Service (APHIS), in conjunction with State Animal Health and Wildlife Officials, are conducting a comprehensive epidemiological investigation and enhanced surveillance in response to the detection. A commercial broiler breeder premises {in Mississippi}. Clinical signs included increased mortality. Depopulation was completed 13 Mar 2025. Source: WOAH,  https://wahis.woah.org/#/in-review/6340 ____
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Cross-species and #mammal-to-mammal #transmission of clade 2.3.4.4b highly pathogenic avian #influenza A #H5N1 with #PB2 adaptations

By G.M.
Abstract Highly pathogenic H5N1 avian influenza viruses (HPAIV) belonging to lineage 2.3.4.4b emerged in Chile in December 2022, leading to mass mortality events in wild birds, poultry, and marine mammals and one human case . We detected HPAIV in 7,33% (714/9745) of cases between December 2022–April 2023 and sequenced 177 H5N1 virus genomes from poultry, marine mammals, a human, and wild birds spanning >3800 km of Chilean coastline . Chilean viruses were closely related to Peru’s H5N1 outbreak, consistent with north-to-south spread down the Pacific coastline . One human virus and nine marine mammal viruses in Chile had the rare PB2 D701N mammalian-adaptation mutation and clustered phylogenetically despite being sampled 5 weeks and hundreds of kilometers apart . These viruses shared additional genetic signatures , including another mammalian PB2 adaptation (Q591K, n = 6), synonymous mutations, and minor variants. Several mutations were detected months later in sealions in the Atlanti...
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