Avian Pathology最新文献

{"title":"Genomic characterization of infectious bursal disease virus in Argentina provides evidence of the recent transcontinental spread of Chinese genotype A2dB1b.","authors":"Gonzalo Tomás, Claudia Techera, Ana Marandino, Valeria Olivera, Joaquín Williman, Yanina Panzera, Ruben Pérez, Ariel Vagnozzi","doi":"10.1080/03079457.2024.2355918","DOIUrl":"10.1080/03079457.2024.2355918","url":null,"abstract":"<p><p>The infectious bursal disease virus (IBDV) is a significant pathogen affecting the poultry industry worldwide. Its epidemiological history has been marked by the emergence of strains with different antigenic, pathogenic, and genetic features, some of which have shown notable spread potential. The A2dB1b genotype, also known as novel variant, has become widespread and gained increased relevance in IBDV epidemiology. This genotype was described in China in the 2010s and rapidly spread in Asia and Africa. The present study describes the circulation of the A2dB1b genotype in Argentina. Applying a next-generation sequencing approach, we obtained the complete coding sequence of 18 Argentine viruses. The high level of genomic homogeneity observed amongst these viruses, their monophyletic clustering in both partial and complete segments A and B derived phylogenies, and their close relatedness to some Chinese strains suggest that a unique transcontinental spread event from China to Argentina occurred recently. The apparent success of the A2dB1b genotype spreading throughout Asia, Africa, and South America may partially be due to specific amino acid characteristics. Novel residues in the hypervariable region of VP2 may help A2dB1b IBDVs evade the protection elicited by the applied commercial vaccines. Our findings underscore the importance of continuous characterization of field samples and evaluation of the control measures currently applied to fight against this specific IBDV genotype.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140915963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avian Diseases 68.2 Table of Contents.","authors":"","doi":"10.1080/03079457.2024.2389684","DOIUrl":"https://doi.org/10.1080/03079457.2024.2389684","url":null,"abstract":"","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interference between <i>Escherichia coli</i> genotypes from the <i>E. coli</i> peritonitis syndrome given simultaneously to productive SPF White Leghorn hens by intratracheal inoculation.","authors":"W J M Landman, J H H van Eck, A E Heuvelink","doi":"10.1080/03079457.2024.2334683","DOIUrl":"10.1080/03079457.2024.2334683","url":null,"abstract":"<p><p>The purpose of the present study was to examine if potentiation of mortality occurred after simultaneous administration of several <i>Escherichia coli</i> genotypes, each capable of inducing the <i>E. coli</i> peritonitis syndrome, in comparison with single genotype application. Five groups of productive specified pathogen free White Leghorn hens were housed in isolators. Groups 1-4 consisted of 32 hens each, group 5 of 10 hens. At 32 weeks of age all groups were inoculated intratracheally. Groups 1 and 2 were inoculated with a mix of four <i>E. coli</i> genotypes and groups 3 and 4 with a mix of four other genotypes. Groups 1 and 3 were given 1 median lethal dose (LD₅₀) of each genotype per hen and groups 2 and 4 had a dose of 0.1 LD₅₀ per genotype per hen; group 5 was mock inoculated. The experiment ended one week after inoculations. In Group 5, no mortality occurred and gross lesions were absent at <i>post-mortem</i> examination. Mortality in groups 1 and 3 was 84% and 81%, respectively; in groups 2 and 4 59% and 66%, respectively. Although mortality in groups 1 and 3 exceeded the expected 50%, this could not be due to potentiation as cluster analysis of reisolates showed that in individual hens only one genotype was found, indicating interference between <i>E. coli</i> genotypes. In groups all four or only two genotypes were recovered, showing that not all genotypes will induce colibacillosis in all experimental groups. Therefore, broad protection can be best assessed by challenging with various single genotypes.<b>RESEARCH HIGHLIGHTS</b> All four or only two <i>E. coli</i> genotypes were found in groups of hens given mixes of four genotypes.In contrast, only one genotype was found in individual hens.<i>E. coli</i> genotypes interfere with each other in hens after given as a mix.Interference is likely based on a random process.Broad protection can best be assessed by challenging with single genotypes.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140183596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The financial cost of coccidiosis in Algerian chicken production: a major challenge for the poultry sector.","authors":"Abderrahmen Rahmani, Hamza Ahmed Laloui, Radhouane Kara, Mohamed Abdesselem Dems, Nora Cherb, Abdenour Klikha, Damer P Blake","doi":"10.1080/03079457.2024.2336091","DOIUrl":"10.1080/03079457.2024.2336091","url":null,"abstract":"<p><p>Coccidiosis, caused by parasites of the genus <i>Eimeria</i>, is a significant economic burden to the poultry industry. In this study, we conducted a comprehensive analysis to evaluate the financial losses associated with <i>Eimeria</i> infection in chickens in Algeria, relying on data provided by key stakeholders in the Algerian poultry industry to assess sub-clinical as well as clinical impact. We employed the updated 2020 version of a model established to estimate the cost of coccidiosis in chickens, taking into consideration specific cultural and technical aspects of poultry farming in Algeria. The findings predict economic losses due to coccidiosis in chickens of approximately £86.7 million in Algeria for the year 2022, representing £0.30 per chicken raised. The majority of the cost was attributed to morbidity (74.9%), emphasizing the substantial economic impact of reduced productivity including decreased bodyweight gain and increased feed conversion ratio. Costs associated with control measures made up 20.5% of the total calculated cost, with 4.6% of the cost related to mortality. These figures provide a clear indication of the scope and economic impact of <i>Eimeria</i> infection of chickens in Algeria, illustrating the impact of practices common across North Africa. They underscore the ongoing requirement for effective preventive and control measures to reduce these financial losses while improving productivity and welfare, ensuring the economic sustainability of the Algerian poultry industry.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140288093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of the novel infectious bursal disease virus variant in vaccinated poultry flocks in Egypt.","authors":"Momtaz A Shahein, Hesham A Sultan, Ali Zanaty, Amany Adel, Zienab Mosaad, Dalia Said, Ahmed Erfan, Mohamed Samy, Abdullah Selim, Karim Selim, Mahmoud M Naguib, Heba Hassan, Osama El Shazly, Zeinab A El-Badiea, Mahmoud K Moawad, Abdelhafez Samir, Mohamed El Shahaby, Eman Farghaly, Samah Eid, Mohamed N Abdelaziz, Mohamed M Hamoud, Osama Mehana, Naglaa M Hagag, Ahmed Samy","doi":"10.1080/03079457.2024.2348513","DOIUrl":"10.1080/03079457.2024.2348513","url":null,"abstract":"<p><p>Since the detection of antigenically atypical very virulent Infectious bursal disease viruses (vvIBDV) in Egypt in 1999, the country has been experiencing recurrent outbreaks with high mortality rates and typical gross lesions associated with typical vvIBDV. However, a significant change occurred in 2023, marked by a notable increase in reported subclinical IBDV cases. To evaluate the field situation, samples from 21 farms in 2023 and 18 farms from 2021 and 2022, all of which had experienced IBD outbreaks based on clinical diagnosis, were collected, and subjected to VP2-HVR sequencing. Phylogenetic analysis revealed that all samples collected in 2021 and 2022 clustered with classical virulent strains and vvIBDV. In 2023, one sample clustered with the Egyptian vvIBDV, another with classical virulent IBDV, and the rest with the novel variant IBDV (nVarIBDV) circulating in China. The alignment of deduced amino acid sequences for VP2 showed that all Egyptian classic virulent strains were identical to the Winterfield or Lukert strains, while vvIBDV strains exhibited two out of the three typical residues found in Egyptian vvIBDV, namely Y220F and G254S, but not A321T. Meanwhile, all Egyptian variant strains exhibited typical residues found in nVarIBDV. However, all Egyptian variants showed a mutation at position 321 (321V), which represents the most exposed part of the capsid and is known to have a massive impact on IBDV antigenicity, except for one sample that had 318G instead. This report highlights the emergence of a new variant IBDV in Egypt, clustered with the Chinese new variants, spreading subclinically in broiler farms across a wide geographic area.<b>RESEARCH HIGHLIGHTS</b> New variant IBDV which emerged in Egypt clustered with Chinese nVarIBDV.nVarIBDV spread subclinically across a wide geographic area.Mutation at 321 represents capsid's most exposed part, a defining feature.Antigenically modified vvIBDV still circulating in Egypt with typical lesions.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141086698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of B-cell epitopes located on the surface in the PB2 protein of the H9N2 subtype avian influenza virus.","authors":"Yiqin Cai, Guihu Yin, Xiangyu Huang, Jianing Hu, Zichen Gao, Xinyu Guo, Yawei Qiu, Haifeng Sun, Xiuli Feng","doi":"10.1080/03079457.2024.2338816","DOIUrl":"10.1080/03079457.2024.2338816","url":null,"abstract":"<p><p>Avian influenza (AI), caused by H9N2 subtype avian influenza virus (AIV), poses a serious threat to poultry farming and public health due to its transmissibility and pathogenicity. The PB2 protein is a major component of the viral RNA polymerase complex. It is of great importance to identify the antigenic determinants of the PB2 protein to explore the function of the PB2 protein. In this study, the PB2 sequence of H9N2 subtype AIV, from 1090 to 1689 bp, was cloned and expressed. The recombinant PB2 protein with cutting gel was used to immunize BALB/c mice. After cell fusion, the hybridoma cell lines secreting monoclonal antibodies (mAbs) targeting the PB2 protein were screened by indirect ELISA and western blotting, and the antigenic epitopes of mAbs were identified by constructing truncated overlapping fragments in the PB2 protein of H9N2 subtype AIV. The results showed that three hybridoma cell lines (4B7, 4D10, and 5H1) that stably secreted mAbs specific to the PB2 protein were screened; the heavy chain of 4B7 was IgG2α, those of 4D10 and 5H1 were IgG1, and all three mAbs had kappa light chain. Also, the minimum B-cell epitope recognized was ⁴⁷⁵LRGVRVSK⁴⁸² and ⁵²⁸TITYSSPMMW⁵³⁷. Homology analysis showed that these two epitopes were conserved among the different subtypes of AIV strains and located on the surface of the PB2 protein. The above findings provide an experimental foundation for further investigation of the function of the PB2 protein and developing monoclonal antibody-based diagnostic kits.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140334589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Longitudinal Study of Avian Pathogenic Escherichia coli (APEC) serogroups associated with disease in Georgia poultry using molecular serology and virulence gene analysis.","authors":"Klao Runcharoon,Bellanirys Garcia,Breck N Peterson,Meaghan M Young,Margaret E Favro,Nicolle L Barbieri,Doug Waltman,Bridgeth Flores,Emily Dinh,Catherine M Logue","doi":"10.1080/03079457.2024.2403414","DOIUrl":"https://doi.org/10.1080/03079457.2024.2403414","url":null,"abstract":"Avian pathogenic Escherichia coli (APEC) is a significant cause of morbidity, mortality, and production loss to the poultry industry worldwide. Here, we characterized 569 E. coli isolates from avian-diagnosed colibacillosis cases from the state of Georgia, USA. A total of 339 isolates were assigned into 32 serogroups with the majority classifying as O78, O2, O25, O8, O1, O86, O18, and O15. Serogroup O25 was found to link with broilers, while broiler breeders were more often associated with serogroup O1 and pet/ hobby birds with serogroup O8. In addition, some serogroups (O1) were more prevalent in the Summer and Fall. Analysis for virulence-associated genes (VAGs) found 23.20% of isolates did not harbor any genes linked with the APEC pathotype, while ColV plasmid-associated genes (iroN, ompT, hlyF, iss, and aerJ,) were frequently detected among most isolates (with 80 to 96% prevalence) and some of these genes were linked with serogroup. Phylogenetic analysis, classified isolates into phylogenetic groups B2 (27%), G (21%), F (15%), and A (11%). The phylogenetic group B2 isolates also harbored the highest number of VAGs. This study highlights that the current APEC-causing disease in birds in the State of Georgia has identified several emerging serogroups possessing several VAGs that could potentially lead to challenges in colibacillosis control.","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of liposomal hesperetin in broilers: prospects for improving performance, antioxidant potential, immunity, and resistance against <i>Listeria monocytogenes</i>.","authors":"Marwa I Abd El-Hamid, Rania M S El-Malt, Safaa I Khater, Abdelwahab A Abdelwarith, Tarek Khamis, Reham A Abd El-Wahab, Elsayed M Younis, Simon J Davies, Dalia Ibrahim Mohamed, Rania I Mohamed, Shimaa Zayed, Mahmoud A Abdelrahman, Doaa Ibrahim","doi":"10.1080/03079457.2024.2395357","DOIUrl":"10.1080/03079457.2024.2395357","url":null,"abstract":"<p><p>Liposomal encapsulated phytogenics, such as liposomal hesperetin, are considered novel substitutes for antibiotics in the broiler industry owing to their improved nutritional and therapeutic properties. Therefore, our key goal was to investigate liposomal hesperetin impact on broiler growth performance, health, antioxidant status, tight junction proteins (TJP), and resistance against <i>Listeria monocytogenes</i>. Four broiler groups were fed 0, 150, 250, or 400 mg/kg of liposomal hesperetin-supplemented diets and experimentally infected with <i>L. monocytogenes</i> strain. Herein, liposomal hesperetin, especially at higher concentrations, augmented broilers FCR with upregulation of genes encoding TJP (occludin, <i>JAM-2</i>, <i>MUC-2</i>), and antioxidant attributes (<i>GPX-1</i>, <i>SOD-1</i>, <i>CAT</i>, <i>HO-1</i>, <i>NQO1</i>, <i>COX2</i>), which reflect enhancing health and welfare of broilers. Muscle antioxidant biomarkers were enhanced; meanwhile, muscle MDA, ROS, and H₂O₂ levels were reduced in response to 400 mg/kg of liposomal hesperetin. Liposomal hesperetin fortification reduced <i>L. monocytogenes</i> loads and expression levels of its virulence-related genes (<i>flaA, hlyA,</i> and <i>ami</i>). Remarkably, histopathological alterations in intestinal and brain tissues of <i>L. monocytogenes</i>-infected broilers were restored post-inclusion at higher levels of liposomal hesperetin, which reflects increase of the birds' resistance to <i>L. monocytogenes</i> infection. Transcription levels of genes encoding cytokines/chemokines (<i>MyD88</i>, <i>AVBD6</i>, <i>CCL20</i>, <i>IL-1β</i>, <i>IL-18</i>), and autophagy (<i>Bcl-2</i>, <i>LC3</i>, <i>AMPK</i>, <i>AKT</i>, <i>CHOP</i>, <i>Bip</i>, <i>p62</i>, <i>XBP1</i>) were ameliorated following dietary liposomal hesperetin fortification, which suggests enhancement of the birds' immunity and health. Collectively, our research recommends liposomal hesperetin application in broiler diets owing to its promoting impact on growth performance, antioxidant status, immunity, health, and welfare besides its antibacterial, and antivirulence characteristics to fight against <i>L. monocytogenes</i>.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142016241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seroprevalence of infectious bursal disease and its associated risk factors in Ethiopia: a systematic review and meta-analysis.","authors":"Solomon Lulie Abey, Gashaw Getaneh Dagnaw, Anmaw Shite Abat, Asnakew Mulaw Berihun, Zewdu Seyoum Tarekegn, Takele Adugna, Abebe Belete Bitew","doi":"10.1080/03079457.2024.2393613","DOIUrl":"10.1080/03079457.2024.2393613","url":null,"abstract":"<p><p>The poultry population is an integral part of Ethiopia's Gross Domestic Product (GDP) but, due to various infectious diseases such as infectious bursal disease (IBD), the expected economic impact in the country remains limited. The status of the disease in Ethiopia is obscured; thus, a systematic review and meta-analysis were employed to estimate the overall pooled prevalence of IBD in Ethiopia. Meta-analysis was conducted to determine the effects of each identified risk factor, while meta-regression and sub-group analysis were employed to assess the relationship between study-level covariates and effect size. The pooled prevalence of IBD in Ethiopia was 69.4% (95% CI 30.7-96.2), while the pooled logit prevalence was 0.94 (95% CI: 0.68-1.20) with significant inter-study variance (<i>Q</i> test = 948.28, df = 43, <i>P</i> < 0.001; <i>τ</i>² = 0.71, <i>I</i>²= 95.47%). A small-study effect was detected in the regression-based Egger test (Prob > |<i>z</i>| < 0.0001). Significant variation was observed among different groups such as sex, age, breed, and type of farm of the chickens. The effect size for the study period from 2018 to 2021 was significantly lower by -0.204 compared to the study period from 2009 to 2015 (<i>P</i> < 0.0001. In conclusion, the IBD pooled prevalence estimate is high, even though the number of studies in the country is insufficient. The high prevalence of the disease requires prompt attention from all stakeholders in the sector to bring it under control through comprehensive disease prevention and control intervention strategies.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lessons Learnt on Infectious Bronchitis Virus Lineage GI-23.","authors":"Avner Finger, Udi Ashash, Dana Goldenberg, Ziv Raviv","doi":"10.1080/03079457.2024.2398030","DOIUrl":"https://doi.org/10.1080/03079457.2024.2398030","url":null,"abstract":"<p><p><b>ABSTRACT</b><i>Infectious bronchitis virus</i> (IBV) is the first Coronavirus discovered in the world in the early 1930s and despite decades of extensive immunoprophylaxis efforts, it remains a major health concern to poultry producers worldwide. Rapid evolution due to large poultry population sizes coupled with high mutation and recombination events and the reliance of the antiviral immune response on specific antibodies against the epitopes of the S1 glycoprotein, render the control of IBV extremely challenging. The numerous and rapidly evolving genetic and antigenic IBV types are currently classified based on the whole S1 gene sequence, into 36 lineages clustered in 8 genotypes. Most lineages (29) are grouped in Genotype I (GI). \"Variant 2\" (<i>Israel/Variant 2/1998</i>) is the prototype strain of lineage GI-23 and since this lineage emergence during the mid-1990s in the Middle East, it has evolved into numerous genetically related strains and disseminated to 5 continents. The hallmarks of IBV Variant 2-like strain infections are high virulence and remarkable nephrotropism and nephropathogenicity, however the molecular mechanisms of these traits remain to be elucidated. Limited protection from previously utilized vaccine strains and accumulated losses to poultry producers have urged the development and implementation of homologous Variant 2-like vaccine strains. The latest Avian Coronavirus biology with specific emphasis on the cumulative knowledge about IBV \"Variant 2\" and related strains' emergence, characteristics and control are reviewed.</p>","PeriodicalId":8788,"journal":{"name":"Avian Pathology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142071858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}