Explore the vast range of titles available.

Newcastle disease (ND), caused by Newcastle disease virus (NDV), is a contagious disease that affects a variety of domestic and wild avian species. Though ND is vaccine-preventable, it is a persistent threat to poultry industry across the globe. The disease represents a leading cause of morbidity and mortality in chickens. To better understand the epidemiology of NDV among commercial and backyard chickens of Odisha, where chicken farming is being prioritized to assist with poverty alleviation, a cross-sectional study was conducted in two distinct seasons during 2018. Choanal swabs ( n = 1361) from live birds (commercial layers, broilers, and backyard chicken) and tracheal tissues from dead birds ( n = 10) were collected and tested by real-time reverse transcription polymerase chain reaction (RT-PCR) for the presence of matrix (M) and fusion (F) genes of NDV. Risk factors at the flock and individual bird levels (health status, ND vaccination status, geographical zone, management system, and housing) were assessed using multivariable logistic regression analyses. Of the 1371 samples tested, 160 were positive for M gene amplification indicating an overall apparent prevalence of 11.7% (95% CI 10.1–13.5%). Circulation of virulent NDV strains was also evident with apparent prevalence of 8.1% (13/160; 95% CI: 4.8–13.4%). In addition, commercial birds had significantly higher odds (75%) of being infected with NDV as compared to backyard poultry ( p = 0.01). This study helps fill a knowledge gap in the prevalence and distribution of NDV in apparently healthy birds in eastern India, and provides a framework for future longitudinal research of NDV risk and mitigation in targeted geographies—a step forward for effective control of ND in Odisha.

Avian influenza virus (AIV) variants emerge frequently, which challenges rapid diagnosis. Appropriate diagnosis reaching the sub- and pathotype level is the basis of combatting notifiable AIV infections. Real-time RT-PCR (RT-qPCR) has become a standard diagnostic tool. Here, a total of 24 arrayed RT-qPCRs is introduced for full subtyping of 16 hemagglutinin and nine neuraminidase subtypes of AIV. This array, designated Riems Influenza A Typing Array version 2 (RITA-2), represents an updated and economized version of the RITA-1 array previously published by Hoffmann et al. RITA-2 provides improved integration of assays (24 instead of 32 parallel reactions) and reduced assay volume (12.5 µL). The technique also adds RT-qPCRs to detect Newcastle Disease (NDV) and Infectious Bronchitis viruses (IBV). In addition, it maximizes inclusivity (all sequences within one subtype) and exclusivity (no intersubtypic cross-reactions) as shown in validation runs using a panel of 428 AIV reference isolates, 15 reference samples each of NDV and IBV, and 122 clinical samples. The open format of RITA-2 is particularly tailored to subtyping influenza A virus of avian hosts and Eurasian geographic origin. Decoupling and re-arranging selected RT-qPCRs to detect specific AIV variants causing epizootic outbreaks with a temporal and/or geographic restriction is possible.

Background Newcastle disease virus (NDV) is a causative agent of Newcastle disease (ND), a major infectious poultry disease associated with significant economic losses. Vaccination is usually effective at preventing the disease. However, in Ethiopia, ND is commonly detected in both unvaccinated and vaccinated chickens. In this study, we aimed to evaluate the pathogenicity of NDV isolated from both vaccinated and unvaccinated chickens, as well as to compare the antigenicity of the isolates with vaccine strains and genotyping by using the F -gene sequence. Methods The partial F gene sequences of all isolates and the mean death times (MDTs) of representative isolates were used to determine genotype and pathogenicity of the isolates. Antigenicities were assayed with the hemagglutinin inhibition (HI) and virus neutralization (VN) tests using antiserum against the vaccine Hitchner B1 (HB1), which is the most commonly used NDV vaccine in Ethiopia. Thermostability was evaluated by incubating infected allantoic fluid at 56 °C. Results Out of 231 samples tested, 10.8% (25/231) were positive for virus isolation. The F gene cleavage sites of all 25 isolates had 112 RRQKRF 117 , a characteristic of virulent NDVs. The MDTs of representative isolates were less than 60 h, indicating highly virulent (velogenic) pathotypes. The HI test revealed significant differences between our isolates and the HB1 vaccine strain, but the VN test showed no antigenic difference. Phylogenetic analysis based on the partial F gene sequences showed that all the isolates belonged to sub-genotype VII.1.1 of genotype VII, which is closely related to NDV strains from the Middle East and Eritrea. Thermostability test showed two of the 25 isolates were thermostable. Discussion Although the HI test indicates antigenic differences between the velogenic Ethiopian isolates and the HB1 vaccine, the VN test showed that the vaccine could protect infections with these isolates. Phylogenetic analysis showed that all studied isolates belong to sub-genotype VII.1.1 of genotype VII, diverging from previously reported genotype XXI in Ethiopia. Conclusions In Ethiopia, NDV genotype VII 1.1 is widely distributed. Since these viruses showed the same antigenicity as the HB1 vaccine in VN test, the occurrence of ND in vaccinated chickens may be due to vaccine failure caused by inadequate management or immunosuppression due to other infectious diseases.

Both avian influenza (AI) and Newcastle disease (ND) viruses cause highly contagious respiratory diseases in chicken. These viruses are transmitted through the oro-faecal route, with airborne transmission via virus-laden droplets or dust. In this study, the Coriolis ® µ air sampler was evaluated for its suitability to assess the air detection and dispersion of highly pathogenic avian influenza virus (HPAIV) or live Newcastle disease virus (NDV) vaccines between chickens in both experimental and field settings. Experimental assays demonstrated HPAIV and NDV detection in air samples, indicating aerial persistence beyond the end of viral shedding measured in tracheal and cloacal swabs. Viral particles were detected in field air samples taken inside and outside HPAIV H5N1 outbreak farms, with outside aerial dispersion reaching up to 40 m from the exhaust fans. In accordance with these findings, viral particles were detected in air samples both indoors and outdoors from three live NDV-vaccinated farms; however, their aerial dispersion extended only up to 5 m from the exhaust fans. As observed in the NDV controlled assays, high levels of viral concentrations persisted in the air samples, whereas the viral concentrations in the individual swabs collected from the chickens were lower in the live NDV-vaccinated farms. For both the HPAIV and NDV field data, chicken density seemed to impact the viral air concentrations within and outside the studied farms. Coriolis ® µ proved effective as a non-invasive method for diagnosing AIV and NDV in both experimental and field studies, highlighting the value of air samples for monitoring poultry disease outbreaks.

Newcastle disease (ND) virus (NDV) infection ranks among the most important poultry diseases globally. In Nigeria, ND remains a persistent menace to poultry production, marked by recurrent outbreaks. However, there is limited understanding of the evolutionary changes and transmission dynamics of the virus in the region. A molecular epidemiological study was conducted to elucidate the evolutionary and transmission patterns of NDV in Nigeria. Phylogenetic analysis of seven NDV isolates from cases recorded between 2023 and 2024 in four Northeastern states exhibited genetic diversity and formed distinct clusters that correspond to the prevailing subgenotype XIV.2. The maximum clade credibility (MCC) tree suggests sustained local circulation of the dominant NDV lineage, likely preceded by an international introduction from Southeast Asia. The fusion genes of the Nigerian genotype XIV and another important genotype XVII are mainly under negative selection, but codons 516 (XIV) and 114 (XVII) consistently show positive selection. The Nextstrain analysis reveals ongoing local evolution and genetic diversity of NDV in West Africa, and Central Nigeria acting as a key transmission hub, with evidence of reintroductions from neighboring countries. These findings have implications for NDV control and prevention strategies in Nigeria, highlighting the need for enhanced NDV surveillance, transboundary transmission control, and development of a vaccine tailored to the circulating NDV genotypes. The study also contributes to the understanding of regional spread pattern of NDV and informs evidence‐based policies for mitigating the impact of the disease on poultry production.

The emergence of new virulent genotypes and the continued genetic drift of Newcastle disease virus (NDV) implies that distinct genotypes of NDV are simultaneously evolving in different geographic locations across the globe, including throughout Africa, where NDV is an important veterinary pathogen. Expanding the genomic diversity of NDV increases the possibility of diagnostic and vaccine failures. In this review, we systematically analyzed the genetic diversity of NDV genotypes in Africa using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Information published between 1999 and 2022 were used to obtain the genetic background of different genotypes of NDV and their geographic distributions in Africa. The following genotypes were reported in Africa: I, II, III, IV, V, VI, VII, VIII, XI, XIII, XIV, XVII, XVIII, XX, and XXI. A new putative genotype has been detected in the Democratic Republic of the Congo. However, of 54 African countries, only 26 countries regularly report information on NDV outbreaks, suggesting that this number may be vastly underestimated. With eight different genotypes, Nigeria is the country with the greatest genotypic diversity of NDV among African countries. Genotype VII is the most prevalent group of NDV in Africa, which was reported in 15 countries. A phylogeographic analysis of NDV sequences revealed transboundary transmission of the virus in Eastern Africa, Western and Central Africa, and in Southern Africa. A regional and continental collaboration is recommended for improved NDV risk management in Africa.

Background Newcastle disease (ND) is a major viral infection of poultry caused by virulent strains of avian paramyxovirus type 1, resulting in considerable global economic losses. In Ethiopia, ND outbreaks persist despite vaccination efforts, and the genetic diversity of circulating Newcastle disease virus (NDV) strains remains poorly characterized. Most previous studies have relied on partial genomic data, leaving a gap in whole-genome analysis. This study aimed to provide a comprehensive genomic investigation of NDV in Ethiopia. Methodology A cross-sectional study was conducted on 14 commercial chicken farms across five districts in central Ethiopia and parts of the Amhara region. A total of 63 pooled specimens were screened using real-time qRT-PCR. Virus isolation was performed in specific-pathogen-free embryonated chicken eggs and confirmed by qRT-PCR. For molecular characterization, the sequence-independent, single-primer amplification (SISPA) technique was applied to obtain whole-genome sequences from five NDV isolates via Oxford Nanopore sequencing Technology. Result Of the 63 pooled specimens, 11 (13.8%) tested positive for NDV. Whole-genome sequencing revealed two genome sizes (15,192 and 15,186 nucleotides) and confirmed virulent NDV strains with the characteristic F-gene cleavage site motif ( 112 RRQKRF 117 ), distinct from local vaccine strains ( 112 GRQGR↓L 117 ). Phylogenetic analysis showed that all isolates clustered within genotype VII, with four strains (GenBank: PV189285 – PV189288 ) exhibiting 97.24% similarity to Iranian NDV strains (accession number: ON184061 ) of sub-genotype VII.1.1. Conclusion This study provides the first whole-genome insight into NDV strains circulating in Ethiopia’s poultry industry. The detection of virulent NDV in vaccinated flocks highlights the need for vaccines that are genetically and antigenically matched to circulating strains. Broader genomic surveillance across production systems is essential to guide effective ND control strategies and reduce economic losses.

Newcastle Disease (ND) remains a major threat to poultry production worldwide, particularly in regions where it is endemic, like Southern Asia. The disease is caused by virulent forms of avian paramyxovirus-1, commonly termed Newcastle Disease Virus (NDV), a highly contagious virus with significant genetic diversity and evolving pathogenicity. This study aimed to molecularly characterize NDV isolates obtained from chickens and pheasants during the 2020/21 ND outbreaks in Nepal, to understand their genetic makeup, phylogenetic relationships, and implications for control strategies. Necropsy samples, including trachea, liver, intestine, spleen, lungs, heart, and proventriculus were collected from ten birds. Isolates from five clinical samples were typed as NDV by hemagglutination and hemagglutination inhibition (HA/HI) assays and were subjected to whole genome sequencing (WGS). Full genomes of 15,192 nucleotides were recovered from each isolate. Fusion (F) gene sequence analysis revealed the presence of multi-basic cleavage site motif 112 RRQKRF 117 in all isolates, indicative of virulent strain and suggesting a potentially velogenic or mesogenic phenotype. Phylogenetic analyses consistently classified all isolates within genotype VII.2 of class II NDV. Further comparative analysis indicated a close genetic relationship between the Nepalese isolates and strains reported from India and Bangladesh, and BEAST analysis suggested Southern Asia as the likely source of introduction into Nepal. These viral genomes provide additional insight into contemporary NDV circulating in an area of endemicity.

Between 2019 and 2023, 163 cases of subgenotype VII.1.1 Newcastle disease virus infection were registered in backyard poultry in the Russian Federation within the framework of epizootiological monitoring. Subgenotype VII.1.1 Newcastle disease virus was reported in a total of 18 different subjects of the Russian Federation. Most of the Newcastle disease outbreaks caused by the viruses of this subgenotype occurred in the autumn and winter period (60%). Further tests allowed for the determination of complete F and HN gene nucleotide sequences for 40 isolates. The results were used to perform the Bayesian analysis of F gene sequences with BEAST v.1.10.4 software. The obtained nucleotide substitution accumulation rates were practically non-dependent on the selected nucleotide substitution model and varied appreciably depending on the applied molecular clock model (0.0018 and 0.002 site-1year-1). The conducted study established that the formation of the ‘Russian’ NDV isolates of subgenotype VII.1.1 followed several stages. In the early 2000s, ancestral viruses belonging to subgenotype VII-d were detected in the Middle East and Eastern Europe. From these, through intermediate forms identified in Iraq around 2007–2008, a group designated as subgenotype VII-L emerged. This group gave rise to two sister clades: the Iranian subgenotype VII-L and the cluster of isolates from Russia and Poland, whose immediate common ancestor likely existed around 2015–2016, probably in Asia.

Wild waterbirds are circulating important RNA viruses, such as avian coronaviruses, avian astroviruses, avian influenza viruses, and avian paramyxoviruses. Waterbird migration routes cover vast territories both within and between continents. The breeding grounds of many species are in the Arctic, but research into this region is rare. This study reports the first Newcastle disease virus (NDV) detection in Arctic Russia. As a result of a five-year study (from 2019 to 2023) of avian paramyxoviruses and avian influenza viruses in wild waterbirds of the Taimyr Peninsula, whole-genome sequences of NDV and H3N8 were obtained. The resulting influenza virus isolate was phylogenetically related to viruses that circulated between 2021 and 2023 in Eurasia, Siberia, and Asia. All NDV sequences were obtained from the Herring gull, and other gull sequences formed a separate gull-like clade in the sub-genotype I.1.2.1, Class II. This may indirectly indicate that different NDV variants adapt to more host species than is commonly believed. Further surveillance of other gull species may help to test the hypothesis of putative gull-specific NDV lineage and better understand their role in the evolution and global spread of NDV.