Front Vet Sci . Association of biosecurity and hygiene practices with avian influenza A/H5 and A/H9 virus infections in turkey farms

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Front Vet Sci


. 2024 Mar 14:11:1319618.
doi: 10.3389/fvets.2024.1319618. eCollection 2024. Association of biosecurity and hygiene practices with avian influenza A/H5 and A/H9 virus infections in turkey farms

Ariful Islam[SUP] 1 2 [/SUP], Monjurul Islam[SUP] 3 [/SUP], Pronesh Dutta[SUP] 3 [/SUP], Md Ashiqur Rahman[SUP] 3 [/SUP], Abdullah Al Mamun[SUP] 3 [/SUP], Akm Dawlat Khan[SUP] 3 [/SUP], Mohammed Abdus Samad[SUP] 4 [/SUP], Mohammad Mahmudul Hassan[SUP] 5 6 [/SUP], Mohammed Ziaur Rahman[SUP] 7 [/SUP], Tahmina Shirin[SUP] 3 [/SUP]



Affiliations

• PMID: 38550782
• PMCID: PMC10976562
• DOI: 10.3389/fvets.2024.1319618

Abstract

High pathogenicity avian influenza (HPAI) H5N1 outbreaks pose a significant threat to the health of livestock, wildlife, and humans. Avian influenza viruses (AIVs) are enzootic in poultry in many countries, including Bangladesh, necessitating improved farm biosecurity measures. However, the comprehension of biosecurity and hygiene practices, as well as the infection of AIV in turkey farms, are poorly understood in Bangladesh. Therefore, we conducted this study to determine the prevalence of AIV subtypes and their association with biosecurity and hygiene practices in turkey farms. We collected oropharyngeal and cloacal swabs from individual turkeys from 197 farms across 9 districts in Bangladesh from March to August 2019. We tested the swab samples for the AIV matrix gene (M gene) followed by H5, H7, and H9 subtypes using real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). We found 24.68% (95% CI:21.54-28.04) of turkey samples were AIV positive, followed by 5.95% (95% CI: 4.33-7.97) for H5, 6.81% (95% CI: 5.06-8.93) for H9 subtype and no A/H7 was found. Using a generalized linear mixed model, we determined 10 significant risk factors associated with AIV circulation in turkey farms. We found that the absence of sick turkeys, the presence of footbaths, the absence of nearby poultry farms, concrete flooring, and the avoidance of mixing newly purchased turkeys with existing stock can substantially reduce the risk of AIV circulation in turkey farms (odds ratio ranging from 0.02 to 0.08). Furthermore, the absence of nearby live bird markets, limiting wild bird access, no visitor access, improved floor cleaning frequency, and equipment disinfection practices also had a substantial impact on lowering the AIV risk in the farms (odds ratio ranging from 0.10 to 0.13). The results of our study underscore the importance of implementing feasible and cost-effective biosecurity measures aimed at reducing AIV transmission in turkey farms. Particularly in resource-constrained environments such as Bangladesh, such findings might assist governmental entities in enhancing biosecurity protocols within their poultry sector, hence mitigating and potentially averting the transmission of AIV and spillover to humans.

Keywords: H9N2; HPAI H5N1; poultry; prevalence; risk factors; zoonotic.

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EFSA J . Avian influenza overview December 2023-March 2024

EFSA J


. 2024 Mar 28;22(3):e8754.
doi: 10.2903/j.efsa.2024.8754. eCollection 2024 Mar.
Avian influenza overview December 2023-March 2024

European Food Safety Authority; European Centre for Disease Prevention and Control; European Union Reference Laboratory for Avian Influenza; Alice Fusaro, José L Gonzales, Thijs Kuiken, Gražina Mirinavičiūtė, Éric Niqueux, Karl Ståhl, Christoph Staubach, Olov Svartström, Calogero Terregino, Katriina Willgert, Francesca Baldinelli, Roxane Delacourt, Alexandros Georganas, Lisa Kohnle

• PMID: 38550271
• PMCID: PMC10977096
• DOI: 10.2903/j.efsa.2024.8754

Abstract

Between 2 December 2023 and 15 March 2024, highly pathogenic avian influenza (HPAI) A(H5) outbreaks were reported in domestic (227) and wild (414) birds across 26 countries in Europe. Compared to previous years, although still widespread, the overall number of HPAI virus detections in birds was significantly lower, among other reasons, possibly due to some level of flock immunity in previously affected wild bird species, resulting in reduced contamination of the environment, and a different composition of circulating A(H5N1) genotypes. Most HPAI outbreaks reported in poultry were primary outbreaks following the introduction of the virus by wild birds. Outside Europe, the majority of outbreaks in poultry were still clustered in North America, while the spread of A(H5) to more naïve wild bird populations on mainland Antarctica is of particular concern. For mammals, A(H5N5) was reported for the first time in Europe, while goat kids in the United States of America represented the first natural A(H5N1) infection in ruminants. Since the last report and as of 12 March 2024, five human avian influenza A(H5N1) infections, including one death, three of which were clade 2.3.2.1c viruses, have been reported by Cambodia. China has reported two human infections, including one fatal case, with avian influenza A(H5N6), four human infections with avian influenza A(H9N2) and one fatal case with co-infection of seasonal influenza A(H3N2) and avian influenza A(H10N5). The latter case was the first documented human infection with avian influenza A(H10N5). Human infections with avian influenza remain rare and no sustained human-to-human infection has been observed. The risk of infection with currently circulating avian H5 influenza viruses of clade 2.3.4.4b in Europe remains low for the general population in the EU/EEA. The risk of infection remains low to moderate for those occupationally or otherwise exposed to infected animals.

Keywords: HPAI; avian influenza; captive birds; humans; monitoring; poultry; wild birds.

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Viruses . Avian H6 Influenza Viruses in Vietnamese Live Bird Markets during 2018-2021

Viruses


. 2024 Feb 27;16(3):367.
doi: 10.3390/v16030367. Avian H6 Influenza Viruses in Vietnamese Live Bird Markets during 2018-2021

Lizheng Guan[SUP] 1 [/SUP], Lavanya Babujee[SUP] 1 [/SUP], Robert Presler[SUP] 1 [/SUP], David Pattinson[SUP] 1 [/SUP], Hang Le Khanh Nguyen[SUP] 2 [/SUP], Vu Mai Phuong Hoang[SUP] 2 [/SUP], Mai Quynh Le[SUP] 2 [/SUP], Harm van Bakel[SUP] 3 [/SUP], Yoshihiro Kawaoka[SUP] 1 4 5 6 [/SUP], Gabriele Neumann[SUP] 1 [/SUP]



Affiliations

• PMID: 38543733
• PMCID: PMC10975462
• DOI: 10.3390/v16030367

Abstract

Avian influenza viruses of the H6 subtype are prevalent in wild ducks and likely play an important role in the ecology of influenza viruses through reassortment with other avian influenza viruses. Yet, only 152 Vietnamese H6 virus sequences were available in GISAID (Global Initiative on Sharing All Influenza Data) prior to this study with the most recent sequences being from 2018. Through surveillance in Vietnamese live bird markets from 2018 to 2021, we identified 287 samples containing one or several H6 viruses and other influenza A virus subtypes, demonstrating a high rate of co-infections among birds in Vietnamese live bird markets. For the 132 H6 samples with unique influenza virus sequences, we conducted phylogenetic and genetic analyses. Most of the H6 viruses were similar to each other and closely related to other H6 viruses; however, signs of reassortment with other avian influenza viruses were evident. At the genetic level, the Vietnamese H6 viruses characterized in our study encode a single basic amino acid at the HA cleavage site, consistent with low pathogenicity in poultry. The Vietnamese H6 viruses analyzed here possess an amino acid motif in HA that confers binding to both avian- and human-type receptors on host cells, consistent with their ability to infect mammals. The frequent detection of H6 viruses in Vietnamese live bird markets, the high rate of co-infections of birds with different influenza viruses, and the dual receptor-binding specificity of these viruses warrant their close monitoring for potential infection and spread among mammals.

Keywords: H6; Vietnam; influenza virus; reassortment; surveillance.

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