Role In Transmission Of Virus Research Articles

A Comparative Assessment of the Pathogenic Potential of Newly Discovered Henipaviruses

Recent advances in high-throughput sequencing technologies have led to the discovery of a plethora of previously unknown viruses in animal samples. Some of these newly detected viruses are closely related to human pathogens. A prime example are the henipaviruses. Both Nipah (NiV) and Hendra virus (HeV) cause severe disease in humans. Henipaviruses are of zoonotic origin, and animal hosts, including intermediate hosts, play a critical role in viral transmission to humans. The natural reservoir hosts of NiV and HeV seem to be restricted to a few fruit bat species of the Pteropus genus in distinct geographic areas. However, the recent discovery of novel henipa- and henipa-like viruses suggests that these viruses are far more widespread than was originally thought. To date, these new viruses have been found in a wide range of animal hosts, including bats, shrews, and rodents in Asia, Africa, Europe, and South America. Since these viruses are closely related to human pathogens, it is important to learn whether they pose a threat to human health. In this article, we summarize what is known about the newly discovered henipaviruses, highlight differences to NiV and HeV, and discuss their pathogenic potential.

Investigating the Roles of Coat Protein and Triple Gene Block Proteins of Potato Mop-Top Virus Using a Heterologous Expression System.

Potato mop-top virus (PMTV) is an emerging viral pathogen that causes tuber necrosis in potatoes. PMTV is composed of three single-stranded RNA segments: RNA1 encodes RNA-dependent RNA polymerase, RNA2 contains the coat protein (CP), and RNA3 harbors a triple gene block (TGB 1, TGB2, and TGB3). CP plays a role in viral transmission, while TGB is known to facilitate cell-to-cell and long-distance systemic movement. The role of CP in symptom development, specifically in the presence of TGB genes, was investigated using potato virus X (PVX) as a delivery vehicle to express PMTV genes in the model plant Nicotiana benthamiana. Plants expressing individual genes showed mild symptoms that included leaf curling and crumpling. Interestingly, symptom severity varied among plants infected with three different combinations: CP with TGB1, CP with TGB2, and CP with TGB3. Notably, the combination of CP and TGB3 induced a hypersensitive response, accompanied by stunted growth and downward curling and crumpling. These results suggest the potential role of TGB co-expressed with CP in symptom development during PMTV infection. Additionally, this study demonstrates the use of the PVX-based expression system as a valuable platform for assessing the role of unknown genes in viral pathogenicity.

Survival of African swine fever virus in feed, bedding materials and mechanical vectors and their potential role in virus transmission

Survival of African swine fever virus in feed, bedding materials and mechanical vectors and their potential role in virus transmission

Genomic epidemiology of highly pathogenic avian influenza A (H5N1) virus in wild birds in South Korea during 2021-2022: Changes in viral epidemic patterns.

Clade 2.3.4.4b highly pathogenic avian influenza A (HPAI) viruses have been detected in wild birds worldwide, causing recurrent outbreaks since 2016. During the winter of 2021-2022, we detected one H5N8 and forty-three H5N1 clade 2.3.4.4b HPAI viruses from wild birds in South Korea. Phylogenetic analysis revealed that HA gene of H5N1 viruses was divided into two genetically distinct groups (N1.G1 and N1.G2). Bayesian phylodynamic analysis demonstrated that wild birds play a vital role in viral transmission and long-term maintenance. We identified five genotypes (N1.G1.1, N1.G2, N1.G2.1, N1.G2.2, and N1.G2.2.1) having distinct gene segment constellations most probably produced by reassortments with low-pathogenic avian influenza viruses. Our results suggest that clade 2.3.4.4b persists in wild birds for a long time, causing continuous outbreaks, compared with previous clades of H5 HPAI viruses. Our study emphasizes the need for enhancing control measures in response to the changing viral epidemiology.

Screening, Expression and Identification of Nanobody Against Monkeypox Virus A35R.

The monkeypox (Mpox) virus epidemic presents a significant risk to global public health security. A35R, a crucial constituent of EEV, plays a pivotal role in virus transmission, serves as a vital target for vaccine development, and has potential for serological detection. Currently, there is a dearth of research on nanobodies targeting A35R. The purpose of this study is to identify specific nanobodies target A35R, so as to provide new antibody candidates for Mpox vaccine development and diagnostic kit development. Three nanobodies specific to the monkeypox virus protein A35R were screened from a naïve phage display library. After four rounds of panning, positive phage clones were identified by enzyme-linked immunosorbent assay (ELISA). Further, the nanobody fusion protein was constructed in pNFCG1-IgG1-Fc vector and expressed in HEK293F cells and purified by affinity chromatography. The specificity and affinity of the nanobodies were identified by ELISA. The binding kinetics of the VHH antibody to A35R were assessed via employment of a bio-layer interferometry (BLI) apparatus, thereby determining the nanobodies affinity. The three purified nanobodies showed specific high-affinity binding MPXV A35R, of them, VHH-1 had the best antigen binding affinity (EC50 = 0.010 ug/mL). In addition, VHH-1 on Protein A biosensor can bind Mpox virus A35R, with an affinity constant of 54 nM as determined in BLI assay. In sum, we has obtained three nanobody strains against Mpox virus A35R with significant affinity and specificity, therefore laying an essential foundation for further research as well as the applications of diagnostic and therapeutic tools of Mpox virus.

The feather epithelium contributes to the dissemination and ecology of clade 2.3.4.4b H5 high pathogenicity avian influenza viruses in ducks

ABSTRACT Immature feathers are known replication sites for high pathogenicity avian influenza viruses (HPAIVs) in poultry. However, it is unclear whether feathers play an active role in viral transmission. This study aims to investigate the contribution of the feather epithelium to the dissemination of clade 2.3.4.4b goose/Guangdong/1996 lineage H5 HPAIVs in the environment, based on natural and experimental infections of domestic mule and Muscovy ducks. During the 2016–2022 outbreaks, H5 HPAIVs exhibited persistent and marked feather epitheliotropism in naturally infected commercial ducks. Infection of the feather epithelium resulted in epithelial necrosis and disruption, as well as the production and environmental shedding of infectious virions. Viral and feather antigens colocalized in dust samples obtained from poultry barns housing naturally infected birds. In summary, the feather epithelium contributes to viral replication, and it is a likely source of environmental infectious material. This underestimated excretion route could greatly impact the ecology of HPAIVs, facilitating airborne and preening-related infections within a flock, and promoting prolonged viral infectivity and long-distance viral transmission between poultry farms.

Isokinetic torque curves abnormalities of the knee extensors during patellofemoral syndrome

Patellofemoral pain syndrome (PFPS) is one of the most prevalent causes of anterior knee pain encountered by physicians. Its etiology remains without a clear consensus; however, it is probably multifactorial. One of the main factors seems to be muscular imbalance. Isokinetic assessment is regularly used in this regard to accurately measure muscle function at different modes and speeds and is therefore the investigation of choice in mechanical knee disorders such as PFPS. In the current work, we present figures illustrating a quantitative abnormality in knee extensor (quadriceps) curvatures during the concentric isokinetic test in patients with this disorder. This objectified anomaly occurs sporadically, although it is characteristic of pain during contraction curves. Aside from a deficiency of muscular strength, several factors have been related to these abnormal contraction curves, including the presence of potential musculotendinous retractions and the bone cause of the PFPS. On the other hand, these curve aspects, despite their occurrence during the PFPS, are neither sensitive nor specific.

Prevalence, Risk factors, and Shedding of Human Herpes Virus-8 among Men Having Sex With Men Enrolled in a Pre-exposure Prophylaxis Study.

Seroprevalence and risk factors for Human Herpesvirus-8 (HHV-8) infection among HIV-negative men who have sex with men (MSM) on pre-exposure prophylaxis (PrEP) have not been well characterized. Our objectives were to assess the prevalence and incidence of HHV-8 infection in MSM enrolled on PrEP and assess viral shedding in seropositive participants. The ANRS IPERGAY study enrolled 429 participants in France and Canada to evaluate oral PrEP for HIV-1 prevention. Stored sera samples at day 0 (D0) and last visit were tested for the detection of HHV-8 antibodies using an indirect immunofluorescence assay. Baseline characteristics were analyzed to identify risk factors associated with HHV-8 seropositivity. Among seropositive participants, HHV-8 DNA was quantified on available oral and anal swabs, and ORF-K1 typing performed on HHV-8 positive samples. One hundred participants were seropositive at D0 (prevalence of 24%, 95% Confidence Interval (95%CI): 20·0-28·4) and 18/329 seroconverted during the study (incidence rate of 2·66 per 100 person-years, 95%CI: 1·57-4·20). Risk factors independently associated with baseline HHV-8 seropositivity included older age, high number of sexual partners, chemsex use and HSV-2 seropositivity. Among HHV-8 seropositive participants with available swab(s) for virological analysis, 37/115 (32%) displayed HHV-8 oral shedding, and 5/113 (4.4%) anal shedding at least once. Four patients had positive viral load before seroconversion. Prevalence and incidence of HHV-8 infection were high in HIV-negative PrEP users. Among seropositive participants, HHV-8 DNA is mainly detected in saliva, which may play a major role in viral transmission in this population.

Occult HBV infection among chronic hemodialysis patients and its role in viral transmission

Hepatitis screening pose a vital role among hemodialysis patients, starting from HBsAg to advanced screening using advance technique such as PCR. Occult Hepatitis B infection can be defined as those who are HBsAg negative, HBcAbs positive, and HBV DNA PCR positive. There is a gap of knowledge regarding Occult hepatitis B infection among hemodialysis patients world wild. In Palestine, there is a need to study the Hepatitis screening practices in hemodialysis unites.

High-throughput super-resolution analysis of influenza virus pleomorphism reveals insights into viral spatial organization.

Many viruses form highly pleomorphic particles. In influenza, virion structure is of interest not only in the context of virus assembly, but also because pleomorphic variations may correlate with infectivity and pathogenicity. We have used fluorescence super-resolution microscopy combined with a rapid automated analysis pipeline, a method well-suited to the study of large numbers of pleomorphic structures, to image many thousands of individual influenza virions; gaining information on their size, morphology and the distribution of membrane-embedded and internal proteins. We observed broad phenotypic variability in filament size, and Fourier transform analysis of super-resolution images demonstrated no generalized common spatial frequency patterning of HA or NA on the virion surface, suggesting a model of virus particle assembly where the release of progeny filaments from cells occurs in a stochastic way. We also showed that viral RNP complexes are located preferentially within Archetti bodies when these were observed at filament ends, suggesting that these structures may play a role in virus transmission. Our approach therefore offers exciting new insights into influenza virus morphology and represents a powerful technique that is easily extendable to the study of pleomorphism in other pathogenic viruses.

Licorice-saponin A3 is a broad-spectrum inhibitor for COVID-19 by targeting viral spike and anti-inflammation

Currently, human health due to corona virus disease 2019 (COVID-19) pandemic has been seriously threatened. The coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein plays a crucial role in virus transmission and several S-based therapeutic approaches have been approved for the treatment of COVID-19. However, the efficacy is compromised by the SARS-CoV-2 evolvement and mutation. Here we report the SARS-CoV-2 S protein receptor-binding domain (RBD) inhibitor licorice-saponin A3 (A3) could widely inhibit RBD of SARS-CoV-2 variants, including Beta, Delta, and Omicron BA.1, XBB and BQ1.1. Furthermore, A3 could potently inhibit SARS-CoV-2 Omicron virus in Vero E6 cells, with EC50 of 1.016 μM. The mechanism was related to binding with Y453 of RBD determined by hydrogen-deuterium exchange mass spectrometry (HDX-MS) analysis combined with quantum mechanics/molecular mechanics (QM/MM) simulations. Interestingly, phosphoproteomics analysis and multi fluorescent immunohistochemistry (mIHC) respectively indicated that A3 also inhibits host inflammation by directly modulating the JNK and p38 mitogen-activated protein kinase (MAPK) pathways and rebalancing the corresponding immune dysregulation. This work supports A3 as a promising broad-spectrum small molecule drug candidate for COVID-19.

Age-associated features of norovirus infection analysed in mice.

Norovirus (NoV) is the leading global cause of viral gastroenteritis. Young children bear the highest burden of disease and play a key role in viral transmission throughout the population. However, which host factors contribute to age-associated variability in NoV severity and shedding are not well-defined. The murine NoV (MNoV) strain CR6 causes persistent infection in adult mice and targets intestinal tuft cells. Here we find that natural transmission of CR6 from infected dams occurred only in juvenile mice. Direct oral CR6 inoculation of wild-type neonatal mice led to accumulation of viral RNA in the ileum and prolonged shedding in the stool that was replication-independent. This viral exposure induced both innate and adaptive immune responses including interferon-stimulated gene expression and MNoV-specific antibody responses. Interestingly, viral uptake depended on passive ileal absorption of luminal virus, a process blocked by cortisone acetate administration, which prevented ileal viral RNA accumulation. Neonates lacking interferon signalling in haematopoietic cells were susceptible to productive infection, viral dissemination and lethality, which depended on the canonical MNoV receptor CD300LF. Together, our findings reveal developmentally associated aspects of persistent MNoV infection, including distinct tissue and cellular tropism, mechanisms of interferon regulation and severity of infection in the absence of interferon signalling. These emphasize the importance of defining viral pathogenesis phenotypes across the developmental spectrum and highlight passive viral uptake as an important contributor to enteric infections in early life.

Novel approaches for the rapid development of rationally designed arbovirus vaccines

Vector-borne diseases, including those transmitted by mosquitoes, account for more than 17% of infectious diseases worldwide. This number is expected to rise with an increased spread of vector mosquitoes and viruses due to climate change and man-made alterations to ecosystems. Among the most common, medically relevant mosquito-borne infections are those caused by arthropod-borne viruses (arboviruses), especially members of the genera Flavivirus and Alphavirus. Arbovirus infections can cause severe disease in humans, livestock and wildlife. Severe consequences from infections include congenital malformations as well as arthritogenic, haemorrhagic or neuroinvasive disease. Inactivated or live-attenuated vaccines (LAVs) are available for a small number of arboviruses; however there are no licensed vaccines for the majority of these infections. Here we discuss recent developments in pan-arbovirus LAV approaches, from site-directed attenuation strategies targeting conserved determinants of virulence to universal strategies that utilize genome-wide re-coding of viral genomes. In addition to these approaches, we discuss novel strategies targeting mosquito saliva proteins that play an important role in virus transmission and pathogenesis in vertebrate hosts.For rapid pre-clinical evaluations of novel arbovirus vaccine candidates, representative in vitro and in vivo experimental systems are required to assess the desired specific immune responses. Here we discuss promising models to study attenuation of neuroinvasion, neurovirulence and virus transmission, as well as antibody induction and potential for cross-reactivity. Investigating broadly applicable vaccination strategies to target the direct interface of the vertebrate host, the mosquito vector and the viral pathogen is a prime example of a One Health strategy to tackle human and animal diseases.

Impact of different diets on the survival, pupation, and adult emergence of Culex pipiens biotype molestus larvae, and infectability with the insect-specific Culex Y virus

The current rapidly advancing climate change will affect the transmission of arthropod-borne viruses (arboviruses), mainly through changes in vector populations. Mosquitos of theCulex pipienscomplex play a particularly prominent role in virus transmission in central Europe. Factors that contribute to the vector population density and the ability of those vectors to transmit viral pathogens (vector competence) can include nutrition during the larval stages. To test the influence of larval diet on larval survival and adult emergence, as well as vector competence, several diets varying in their nutritional composition were compared using a newly established assay. We tested the effects of 17 diets or diet combinations on the fitness of third-instar larvae ofCulex pipiensbiotypemolestus.Larval survival rates at day 7 ranged from 43.33% to 94.44%. We then selected 3 of the 17 diets (Tetra Pleco, as the routine feed; JBL NovoTab, as the significantly inferior feed; and KG, as the significantly superior feed) and tested the effect of these diets, in combination with Culex Y virus infection, on larval survival rate. All Culex Y virus-infected larvae showed significantly lower larval survival, as well as low pupation and adult emergence rates. However, none of the tested diets in our study had a significant impact on larval survival in combination with viral infection. Furthermore, we were able to correlate several water quality parameters, such as phosphate, nitrate, and ammonium concentration, electrical conductivity, and low O2saturations, with reduced larval survival. Thus, we were able to demonstrate that Culex Y virus could be a suitable agent to reduce mosquito population density by reducing larval density, pupation rate, and adult emergence rate. When combined with certain water quality parameters, these effects can be further enhanced, leading to a reduced mosquito population density, and reduce the cycle of transmission. Furthermore, we demonstrate, for the first time, the infection of larvae of the mosquitoCulex pipiensbiotypemolestuswith a viral pathogen.

Exploring the Influencing Factors of COVID-19 Vaccination Willingness among Young Adults in China

Vaccine uptake is considered as one of the most effective methods of defending against COVID-19 (coronavirus disease 2019). However, many young adults are hesitant regarding COVID-19 vaccines, and they actually play an important role in virus transmission. Based on a multi-theory model, this study aims to explore the influencing factors related to COVID-19 vaccine willingness among young adults in China. Using semi-structured interviews, this study explored the factors that would motivate young adults with vaccine hesitancy to get the COVID-19 vaccine. Thematic analysis was used to analyze the interview data with topic modeling as a complementarity method. After comparing the differences and similarities of results generated by thematic analysis and topic modeling, this study ultimately identified ten key factors related to COVID-19 vaccination intention, including the effectiveness and safety of vaccines, application range of vaccine, etc. This study combined thematic analysis with machine learning and provided a comprehensive and nuanced picture of facilitating factors for COVID-19 vaccine uptake among Chinese young adults. Results may be taken as potential themes for authorities and public health workers in vaccination campaigns.

Evaluation of the interaction between potent small molecules against the Nipah virus Glycoprotein in Malaysia and Bangladesh strains, accompanied by the human Ephrin-B2 and Ephrin-B3 receptors; a simulation approach.

Malaysia reported the first human case of Nipah virus (NiV) in late September 1998 with encephalitis and respiratory symptoms. As a result of viral genomic mutations, two main strains (NiV-Malaysia and NiV-Bangladesh) have spread around the world. There are no licensed molecular therapeutics available for this biosafety level 4 pathogen. NiV attachment glycoprotein plays a critical role in viral transmission through its human receptors (Ephrin-B2 and Ephrin-B3), so identifying small molecules that can be repurposed to inhibit them is crucial to developing anti-NiV drugs. Consequently, in this study annealing simulations, pharmacophore modeling, molecular docking, and molecular dynamics were used to evaluate seven potential drugs (Pemirolast, Nitrofurantoin, Isoniazid Pyruvate, Eriodictyol, Cepharanthine, Ergoloid, and Hypericin) against NiV-G, Ephrin-B2, and Ephrin-B3 receptors. Based on the annealing analysis, Pemirolast for efnb2 protein and Isoniazid Pyruvate for efnb3 receptor were repurposed as the most promising small molecule candidates. Furthermore, Hypericin and Cepharanthine, with notable interaction values, are the top Glycoprotein inhibitors in Malaysia and Bangladesh strains, respectively. In addition, docking calculations revealed that their binding affinity scores are related to efnb2-pem (- 7.1kcal/mol), efnb3-iso (- 5.8kcal/mol), gm-hyp (- 9.6kcal/mol), gb-ceph (- 9.2kcal/mol). Finally, our computational research minimizes the time-consuming aspects and provides options for dealing with any new variants of Nipah virus that might emerge in the future.

Genetic diversity of Newcastle disease viruses circulating in wild and synanthropic birds in Ukraine between 2006 and 2015.

Newcastle disease virus (NDV) infects a wide range of bird species worldwide and is of importance to the poultry industry. Although certain virus genotypes are clearly associated with wild bird species, the role of those species in the movement of viruses and the migratory routes they follow is still unclear. In this study, we performed a phylogenetic analysis of nineteen NDV sequences that were identified among 21,924 samples collected from wild and synanthropic birds from different regions of Ukraine from 2006 to 2015 and compared them with isolates from other continents. In synanthropic birds, NDV strains of genotype II, VI, VII, and XXI of class II were detected. The fusion gene sequences of these strains were similar to strains detected in birds from different geographical regions of Europe and Asia. However, it is noteworthy to mention the isolation of vaccine viruses from synanthropic birds, suggesting the possibility of their role in viral transmission from vaccinated poultry to wild birds, which may lead to the further spreading of vaccine viruses into other regions during wild bird migration. Moreover, here we present the first publicly available complete NDV F gene from a crow (genus Corvus). Additionally, our phylogenetic results indicated a possible connection of Ukrainian NDV isolates with genotype XXI strains circulating in Kazakhstan. Among strains from wild birds, NDVs of genotype 1 of class I and genotype I of class II were detected. The phylogenetic analysis highlighted the possible exchange of these NDV strains between wild waterfowl from the Azov-Black Sea region of Ukraine and waterfowl from different continents, including Europe, Asia, and Africa.

Detection of neutralising antibodies against SARS-CoV-2 in companion animals in Istanbul

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019 and rapidly spread throughout the world. After the susceptibility of various animals to SARS-CoV-2 infection was reported, the prevalence of COVID-19 infection in pet animals and their role in virus transmission became a source of concern. Seroprevalence of SARS-CoV-2 in pet animals has been reported from various parts of the world to date. In this study, 206 serum samples of household dogs and cats were obtained from a diagnostic laboratory in Istanbul. Ninety-nine of the samples were collected during the second wave (November and December 2020) of the pandemic, and 107 were collected between August and September 2021. Neutralizing antibodies against SARS-CoV-2 in companion animals was investigated by virus neutralization test. Among the 99 serum samples which were collected during the second wave (November and December 2020) of the pandemic, while no neutralizing antibodies were found in 61 sera of cats, one of 38 dogs was positive with a titer of 1/256. Similarly, 0/54 cats and 1/53 dogs were tested positive for the neutralizing antibodies among the samples collected between August and September 2021. This study is demonstrating the evidence of SARS-CoV-2 infection in dogs.

Asymptomatic SARS-CoV-2 Infection by Age: A Global Systematic Review and Meta-analysis.

Asymptomatic SARS-CoV-2 infections have raised concerns for public health policies to manage epidemics. This systematic review and meta-analysis aimed to estimate the age-specific proportion of asymptomatic SARS-CoV-2 infected persons globally by year of age. We searched PubMed, Embase, medRxiv and Google Scholar on September 10, 2020, and March 1, 2021. We included studies conducted during January to December 2020, before routine vaccination against COVID-19. Because we expected the relationship between the asymptomatic proportion and age to be nonlinear, multilevel mixed-effects logistic regression (QR decomposition) with a restricted cubic spline was used to model asymptomatic proportions as a function of age. A total of 38 studies were included in the meta-analysis. In total, 6556 of 14,850 cases were reported as asymptomatic. The overall estimate of the proportion of people who became infected with SARS-CoV-2 and remained asymptomatic throughout infection was 44.1% (6556/14,850, 95% CI: 43.3%-45.0%). The predicted asymptomatic proportion peaked in children (36.2%, 95% CI: 26.0%-46.5%) at 13.5 years, gradually decreased by age and was lowest at 90.5 years of age (8.1%, 95% CI: 3.4%-12.7%). Given the high rates of asymptomatic carriage in adolescents and young adults and their active role in virus transmission in the community, heightened vigilance and public health strategies are needed among these individuals to prevent disease transmission.

Evolution, Transmission, and Pathogenicity of High Pathogenicity Avian Influenza Virus A (H5N8) Clade 2.3.4.4, South Korea, 2014-2016.

During 2014–2016, clade 2.3.4.4 H5N8 high pathogenicity avian influenza virus (HPAIV) caused the largest known avian influenza epidemic in South Korea. Based on data from earlier H5N8 outbreaks, primitive H5N8 virus in South Korea was classified into five subgroups: C1, C2, C3, C4, and C5. The present study investigated the pathogenic and molecular epidemiologic characteristics of H5N8 viruses obtained from 388 cases of poultry farms and 85 cases of wild bird infections in South Korea during 2014–2016. Representative viruses of subgroups C1, C2, and C4 showed significant pathobiological differences in specific pathogen-free (SPF) chickens, with the H1731 (C1) virus showing substantially lower infectivity, transmissibility, and pathogenicity than the H2102 (C2) and H1924 (C4) viruses. Full genome sequence analysis showed the number of mutations that significantly increased in domestic duck-origin H5N8 HPAIVs compared to the viruses from gallinaceous poultry. These differences may have been due to the long-term circulation of viruses in domestic duck farms. The same mutations, at positions 219 and 757 of PB1, independently evolving in the C0, C1, and C2 subgroups may have been positively selected, resulting in convergent evolution at the amino acid level. Bayesian discrete trait phylodynamic analysis (DTA) indicated multiple introductions of H5N8 HPAIV from wild birds into domestic poultry in various regions in South Korea. Following initial viral introduction into domestic duck farms in the western part of Korea, domestic ducks played a major role in viral transmission and maintenance. These findings highlight the need for continued genomic surveillance and pathobiological characterization of HPAIV in birds. Enhanced biosecurity in poultry farms should be implemented to prevent the introduction, maintenance, and spread of HPAIV.