Velogenic Newcastle Disease Virus Research Articles

Molecular characteristics and phylogenetic analysis of pigeon paramyxovirus type 1 isolates from pigeon meat farms in Shanghai (2009–2012)

The majority of pigeon paramyxovirus type 1 (PPMV-1) strains are generally non-pathogenic to chickens; however, they can induce severe illness and high mortality rates in pigeons, leading to substantial economic repercussions. The genomes of 11 PPMV-1 isolates from deceased pigeons on meat pigeon farms during passive monitoring from 2009 to 2012 were sequenced and analyzed using polymerase chain reaction and phylogenetic analysis. The complete genome lengths of 11 isolates were approximately 15,192 nucleotides, displaying a consistent gene order of 3′-NP-P-M-F-HN-L-5′. ALL isolates exhibited the characteristic motif of 112RRQKRF117 at the fusion protein cleavage site, which is characteristic of velogenic Newcastle disease virus. Moreover, multiple mutations have been identified within the functional domains of the F and HN proteins, encompassing the fusion peptide, heptad repeat region, transmembrane domains, and neutralizing epitopes. Phylogenetic analysis based on sequences of the F gene unveiled that all isolates clustered within genotype VI in class II. Further classification identified at least two distinct sub-genotypes, with seven isolates classified as sub-genotype VI.2.1.1.2.2, whereas the others were classified as sub-genotype VI.2.1.1.2.1. This study suggests that both sub-genotypes were implicated in severe disease manifestation among meat pigeons, with sub-genotype VI.2.1.1.2.2 displaying an increasing prevalence among Shanghai’s meat pigeon population since 2011. These results emphasize the value of developing pigeon-specific vaccines and molecular diagnostic tools for monitoring and proactively managing potential PPMV-1 outbreaks.

The haemagglutinin–neuraminidase protein of velogenic Newcastle disease virus enhances viral infection through NF-κB-mediated programmed cell death

The haemagglutinin–neuraminidase (HN) protein, a vital membrane glycoprotein, plays a pivotal role in the pathogenesis of Newcastle disease virus (NDV). Previously, we demonstrated that a mutation in the HN protein is essential for the enhanced virulence of JS/7/05/Ch, a velogenic variant NDV strain originating from the mesogenic vaccine strain Mukteswar. Here, we explored the effects of the HN protein during viral infection in vitro using three viruses: JS/7/05/Ch, Mukteswar, and an HN-replacement chimeric NDV, JS/MukHN. Through microscopic observation, CCK-8, and LDH release assays, we demonstrated that compared with Mukteswar and JS/MukHN, JS/7/05/Ch intensified the cellular damage and mortality attributed to the mutant HN protein. Furthermore, JS/7/05/Ch induced greater levels of apoptosis, as evidenced by the activation of caspase-3/8/9. Moreover, JS/7/05/Ch promoted autophagy, leading to increased autophagosome formation and autophagic flux. Subsequent pharmacological experiments revealed that inhibition of apoptosis and autophagy significantly impacted virus replication and cell viability in the JS/7/05/Ch-infected group, whereas less significant effects were observed in the other two infected groups. Notably, the mutant HN protein enhanced JS/7/05/Ch-induced apoptosis and autophagy by suppressing NF-κB activation, while it mitigated the effects of NF-κB on NDV infection. Overall, our study offers novel insights into the mechanisms underlying the increased virulence of NDV and serves as a reference for the development of vaccines.

A study of the immunomodulatory effects of coconut oil extract in broilers experimentally infected with velogenic Newcastle disease virus.

This study aims to evaluate the immunomodulatory effects of coconut oil extract (COE) in broilers experimentally infected with velogenic Newcastle disease virus (vNDV). A total of 150 broiler birds (day-old) were equally divided into five study groups i.e., negative control, positive control, COE-1, COE-2, and COE-3. On day 10, broilers of groups COE-1, COE-2, and COE-3 were supplemented with 1, 2, and 3 ml of COE respectively per liter of drinking water for 15 days. On day 13, 0.1ml/bird (10-5.25 ELD50) of vNDV was inoculated in broilers of positive control, COE-1, COE-2, and COE-3 groups intramuscularly. During this study, growth performance, morbidity, and mortality rates of each study group were recorded. The antibody titer against NDV was determined on days 7, 14, 21, 28, and 35. The levels of IgY and IgM were also determined on the 7th, 14th, and 21st days post-SRBC inoculation. On day 33, avian tuberculin was injected between the 1st and 2nd toes of the left side (intradermally) to measure lymphoproliferative responses. On day 35, the phagocytic activity in the blood was assessed through a carbon clearance assay by injecting carbon black ink into the right-wing vein. The visceral organs having gross lesions were also collected for histopathology. The COE significantly improved the growth performance, and lowered the morbidity and mortality rates of broilers. There was a significant rise in antibody titers against NDV and levels of IgY and IgM antibodies against SRBC in COE-supplemented broilers. The lymphoproliferative response and phagocytic activity were also enhanced. Among COE-supplemented groups, the broilers of the COE-3 group showed a significant increase in growth performance and boosted immune defense. Coconut oil extract has the potential to boost the growth performance and immune status of broilers. It can be used effectively as a feed additive and alternative to antibiotics to prevent the spread of infectious poultry pathogens.

Isolation and molecular characterization of velogenic Newcastle disease virus genotype VII.1.1 from commercial broilers and wild birds in Matrouh governorate, Egypt

Isolation and molecular characterization of velogenic Newcastle disease virus genotype VII.1.1 from commercial broilers and wild birds in Matrouh governorate, Egypt

Sequential histopathological changes of the lower respiratory and gastrointestinal tracts in chickens infected with velogenic Newcastle disease virus

Velogenic Newcastle disease is a highly contagious and fatal disease that affects domestic poultry, and is clinically manifested by haemorrhagic gastroenteritis and respiratory distress. This study investigated the sequential histopathogic changes in the lungs, proventriculus, and intestines of broiler chickens infected with velogenic Newcastle disease virus (vNDV). Fifty broiler chickens (6-weeks-old) were randomly assigned into two groups of 25 each: UC – unvaccinated with Newcastle disease (ND) vaccines and intranasallly inoculated with vNDV, UU – unvaccinated uninfected. At 4, 5 and 6 days post-infection (d.p.i) tissue samples were collected from birds in each group for histopathology. The lungs showed hyperaemia, haemorrhages, inflammatory oedema and cellular infiltrations in the secondary bronchi, parabronchi (atria, infundibular, air and blood capillaries of the exchange tissue), depletion of bronchial-asociated lymphoid tissues, loss of cilia and hyperplasia of surface epithelium of bronchi and parabronchi at 4 d.p.i. The lesions progressed to collapsed air capillaries with fibroplasia and fibrosis of the area at 6 d.p.i. Similar inflammatory changes were observed in the proventriculus, but accompanied by degeneration and attenuation of surface epithelium of proventiculus and proventricular glands at 4 d.p.i., and severe necrosis and disintegration of the proventricular glands at 6 d.p.i. The intestine showed severe inflammatory changes in the mucosa, submucosa and serosa and depletion of gut-associated lymphoid tissues at 4 d.p.i., and ulcerative enteritis at 5 d.p.i. The lumen was filled with necrotic debris at 6 d.p.i. This study reinforces the concept making pathologic animal experiments important tools for a complete characterization of strains in susceptible animals, as this information will be helpful in the accurate diagnosis of velogenic Newcastle disease in chickens.

Protective effectiveness of two vaccination schemes against the prevalent Egyptian strain of Newcastle disease virus genotype VII.

Despite the strict preventive immunization used in Egypt, Newcastle disease remained a prospective risk to the commercial and backyard chicken industries. The severe economic losses caused by the Newcastle disease virus (NDV) highlight the importance of the trials for the improvement and development of vaccines and vaccination programs. In the present study, we evaluated the effectiveness of two vaccination schemes for protection against the velogenic NDV (vNDV) challenge. Four groups (A-D) of commercial broiler chickens were used. Two groups (G-A and G-B) were vaccinated with priming live HB1 GII simultaneously with inactivated GVII vaccines at 5 days of age, then boosted with live LaSota GII vaccine in group A and live recombinant NDV GVII vaccine in group B on day 16. Groups A to C were challenged with NDV/Chicken/Egypt/ALEX/ZU-NM99/2019 strain (106 Embryo infective dose 50/0.1 ml) at 28 days of age. Two vaccination schemes achieved 93.3% clinical protection against NDV with body gain enhancement; whereas, 80% of the unvaccinated-challenged birds died. On day 28, the mean HI antibody titers were 4.3 ± 0.33 and 5.3 ± 0.33 log2 in groups A and B, respectively. As well as both programs remarkably reduced virus shedding. The two vaccination schemes displayed close protection efficacy against the vNDV challenge. Therefore, using the combination of a live attenuated vaccine with an inactivated genetically matched strain vaccine and then boosting it with one of the available live vaccines could be considered one of the most effective programs against current field vNDV infection in Egypt.

The evaluation and importance of Newcastle disease’s economic loss in commercial layer poultry

Velogenic Newcastle disease virus (VNDV) causes a highly contagious and devastating disease in poultry and causes up to 100 percent mortality in susceptible populations during devastating outbreaks. Newcastle disease causes heavy economic losses to the global poultry industry by decreasing the growth rate, decreasing egg production, and increasing morbidity and mortality. The households face substantial economic losses throughout the year due to Newcastle disease. It is ranked first among other poultry diseases in village chickens. The economic losses caused by this disease in the poultry industry have given awareness about the importance of Newcastle disease and made it easier to justify the operations against this disease. So, estimating the economic losses caused by Newcastle disease is very important. Regarding the Newcastle disease's huge impact on production and causing a lack of eggs, we will have to compensate for this reduction by importing eggs from other countries. Hence, a tremendous amount of money will be needed to compensate for the shortage of eggs, which will result in a huge economic loss. Finally, these will directly affect the poultry industry and its financial resources, which clarifies the importance of correct and on-time vaccination and caring for Newcastle disease in poultry flocks to prevent enormous economic losses. In this study, the economic impact of Newcastle Disease on egg-laying farms was quantitatively assessed. Data were collected on the total number of egg-laying poultry monthly and annually. Subsequently, the economic loss for each period was calculated based on the total production period. The minimal damage caused by this disease is about 116,591 Tons. Summing all these periods' production decreases, the total loss will be 10538 Tons. To estimate the losses of the disease, it is necessary to estimate the losses in breeding herds and broiler herds so that the loss resulting from the endemic Newcastle disease of the country can be measured.

Determination of median embryo lethal dose for a velogenic Newcastle disease virus isolated in Sulaimani/Iraq

Determination of median embryo lethal dose for a velogenic Newcastle disease virus isolated in Sulaimani/Iraq

The in vitro Potential Oncolytic Effect of Lentogenic and Velogenic Newcastle Disease Viruses on MCF-7 and Caco-2 Cell Lines Compared to Chemotherapies

The in vitro Potential Oncolytic Effect of Lentogenic and Velogenic Newcastle Disease Viruses on MCF-7 and Caco-2 Cell Lines Compared to Chemotherapies

Superior Efficacy of Apathogenic Genotype I (V4) over Lentogenic Genotype II (LaSota) Live Vaccines against Newcastle Disease Virus Genotype VII.1.1 in Pathogen-Associated Molecular Pattern-H9N2 Vaccinated Broiler Chickens.

A comparison of the efficacy of apathogenic genotype I (V4) and lentogenic genotype II (LaSota) strains of live Newcastle disease virus (NDV) vaccines was performed following vaccination with pathogen-associated molecular pattern (PAMP) H9N2 avian influenza vaccine and challenge with velogenic NDV genotype VII.1.1 (vNDV-VII.1.1). Eight groups (Gs) of day-old chicks were used (n = 25). Groups 1-4 received a single dose of PAMP-H9N2 subcutaneously, while Gs (1, 5) and (2, 6) received eye drops of V4 and LaSota, respectively, as two doses. All Gs, except for 4 and 8, were intramuscularly challenged with vNDV-VII.1.1 at 28 days of age. No signs were detected in Gs 1, 5, 4, and 8. The mortality rates were 0% in Gs 1, 4, 5, and 8; 40% in G2; 46.66% in G6; and 100% in Gs 3 and 7. Lesions were recorded as minimal in Gs 1 and 5, but mild to moderate in Gs 2 and 6. The lowest significant viral shedding was detected in Gs 1, 2, and 5. In conclusion, two successive vaccinations of broilers with a live V4 NDV vaccine provided higher protection against vNDV-VII.1.1 challenge than LaSota. PAMP-H9N2 with live NDV vaccines induced more protection than the live vaccine alone.

Cellular vimentin regulates the infectivity of Newcastle disease virus through targeting of the HN protein

The haemagglutinin-neuraminidase (HN) protein plays a crucial role in the infectivity and virulence of Newcastle disease virus (NDV). In a previous study, the mutant HN protein was identified as a crucial virulence factor for the velogenic variant NDV strain JS/7/05/Ch, which evolved from the prototypic vaccine strain Mukteswar. Furthermore, macrophages are the main susceptible target cells of NDV. However, the possible involvement of cellular molecules in viral infectivity remains unclear. Herein, we elucidate the crucial role of vimentin, an intermediate filament protein, in regulating NDV infectivity through targeting of the HN protein. Using LC‒MS/MS mass spectrometry and coimmunoprecipitation assays, we identified vimentin as a host protein that differentially interacted with prototypic and mutant HN proteins. Further analysis revealed that the variant NDV strain induced more significant rearrangement of vimentin fibres compared to the prototypic NDV strain and showed an interdependence between vimentin rearrangement and virus replication. Notably, these mutual influences were pronounced in HD11 chicken macrophages. Moreover, vimentin was required for multiple infection processes of the variant NDV strain in HD11 cells, including viral internalization, fusion, and release, while it was not necessary for those of the prototypic NDV strain. Collectively, these findings underscore the pivotal role of vimentin in NDV infection through targeting of the HN protein, providing novel targets for antiviral treatment strategies for NDV.

Circular RNAs are associated with the resistance to Newcastle disease virus infection in duck cells.

Newcastle disease virus (NDV) is prevalent worldwide with an extensive host range. Among birds infected with velogenic NDV strains, chickens experience high pathogenicity and mortality, whereas ducks mostly experience mild symptoms or are asymptomatic. Ducks have a unique, innate immune system hypothesized to induce antiviral responses. Circular RNAs (circRNAs) are among the most abundant and conserved eukaryotic transcripts. These participate in innate immunity and host antiviral response progression. In this study, circRNA expression profile differences post-NDV infection in duck embryo fibroblast (DEF) cells were analyzed using circRNA transcriptome sequencing. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to reveal significant enrichment of differentially expressed (DE) circRNAs. The circRNA-miRNA-mRNA interaction networks were used to predict the related functions of circRNAs. Moreover, circ-FBXW7 was selected to determine its effect on NDV infection in DEFs. NDV infection altered circRNA expression profiles in DEF cells, and 57 significantly differentially expressed circRNAs were identified post-NDV infection. DEF responded to NDV by forming circRNAs to regulate apoptosis-, cell growth-, and protein degradation-related pathways via GO and KEGG enrichment analyses. circRNA-miRNA-mRNA interaction networks demonstrated that DEF cells combat NDV infection by regulating cellular pathways or apoptosis through circRNA-targeted mRNAs and miRNAs. circ-FBXW7 overexpression and knockdown inhibited and promoted viral replication, respectively. DEF cells mainly regulated cell cycle alterations or altered cellular sensing to combat NDV infection. These results demonstrate that DEF cells exert antiviral responses by forming circRNAs, providing novel insights into waterfowl antiviral responses.

Antigenic variation in hemagglutinin-neuraminidase of Newcastle disease virus isolated from Tibet, China

Vaccines are widely used to prevent Newcastle disease virus (NDV). Under the pressure of immunization, NDVs with mutations among epitopes of F and HN protein were isolated, which indicates that the efficiency of vaccine may decrease in terms of preventing emerged NDV. However, the lack of evidences to support whether these mutations contribute to antigenic mutation and immune escape in NDV leading to the controversy that the matched vaccine is more effective than the mismatched vaccine. In this study, a genotype VII velogenic NDV strain (C22) was isolated from a vaccinated farm in Tibet, China. We found that this strain was close to NDV from east China, but it had a specific mutation (K138R) in one epitope (131DYIGGIGKE139) of HN protein. This mutation might change the interaction between amino acids in stalk-head link region of HN protein and then induce the specific antibody to worse recognize the C22 strain, but it did not alter viral virulence and growth ability. Then, the C22 strain was attenuated via modification of the F protein cleavage site to generate a matched vaccine. Comparing to a mismatched vaccine (LaSota), this matched vaccine showed advantages in inhibiting viral shedding and tissue damage. However, both vaccines induced chicken to generate similar level of neutralizing antibodies against C22, C22mut (R138K) and LaSota. These results suggest that the epitope mutation is insufficient to help NDV escaping neutralizing antibodies of vaccinated chicken, supporting that the merits of NDV matched vaccine are not totally related to humoral immunity.

Newcastle disease virus (NDV) recombinant expressing Marek’s disease virus (MDV) glycoprotein B significantly protects chickens against MDV and NDV challenges

Marek’s disease (MD) is a highly contagious viral neoplastic disease of chickens caused by Marek’s disease virus (MDV), resulting in significant economic losses to the poultry industry worldwide. The commonly used live and/or vectored MDV vaccines are expensive to produce and difficult to handle due to the requirement of liquid nitrogen for manufacturing and delivering frozen infected cells that are viable. In this study, we aimed to develop a Newcastle disease virus (NDV) vectored MDV vaccine that can be lyophilized, stored, and transported at 4 °C. Four NDV LaSota (LS) vaccine strain-based recombinant viruses expressing MDV glycoproteins gB, gC, gE, or gI were generated using reverse genetics technology. The biological assessments showed that these recombinant viruses were slightly attenuated in vivo yet retained similar growth kinetics and virus titers in vitro compared to the parental LaSota virus. Vaccination of leghorn chickens (Lines 15I5x71 F1 cross) with these recombinant viruses via intranasal and intraocular routes conferred different levels of protection against virulent MDV challenge. The recombinant expressing the MDV gB protein, rLS/MDV-gB, protected vaccinated birds significantly against MDV-induced tumor formation when challenged at 14 days post-vaccination (DPV) but moderately at 5 DPV. Whereas the other three recombinants provided little protection against the MDV challenge. All four recombinants conferred complete protection against the velogenic NDV challenge. These results demonstrated that the rLS/MDV-gB virus is a safe and efficacious dual vaccine candidate that can be lyophilized and potentially mass-administered via aerosol or drinking water to large chicken populations at a meager cost.

Investigation of Newcastle Disease Virus Infection in Pet Birds in the Southwest of Iran.

Newcastle disease virus (NDV) is a serious threat to the international poultry industry. Therefore, to determine the role of pet birds (Psittaciformes and Passeriformes) in its spread and epidemiology, the presence of this virus in these birds was investigated. In this study, fecal and cloaca swabs from 63 Psittaciformes and 37 Passeriformes, along with tissue samples of dead birds, including proventriculus, trachea, lungs, and intestine, were collected from breeding and sales markets as well as the birds referred to Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Isolation of the virus was performed by injecting the suspension of the samples into the allantoic fluid of fertilized eggs, and NDV was detected in the achieved allantoic fluids by reverse transcription polymerase chain reaction. The NDV was detected in 13 allantoic samples. The partial F gene sequences of 10 positive samples were investigated, and their genetic relationship with each other as well as with other isolates in the gene bank was marked. Consequently, subgenotype VII.1.1 (VIId) was in the locus of all 10 viruses. By the amino acid cleavage site sequences of F protein, 10 isolates were determined as velogenic NDV. Moreover, all sequences were similar to each other and other Iranian isolates. Furthermore, the 112RRQKR/F117 pattern was the main amino acid (aa) sequence in the F-protein Cleavage site for VIId genotype isolates.

Molecular characterization suggests kinetic modulation of expression of accessory viral protein, W, in Newcastle disease virus infected DF1 cells.

The online version contains supplementary material available at 10.1007/s13337-023-00813-2.

Phylogeny and Pathogenicity of Subtype XIIb NDVs from Francolins in Southwestern China and Effective Protection by an Inactivated Vaccine

Most genotype XII newcastle disease viruses (NDVs) were isolated from poultry, chickens, or geese, with the exception of one subtype, XIIa NDV, which was isolated from a peacock. Here, two subtype XIIb NDVs, francolin/China/GX01/2017 and francolin/China/GX02/2017 (GX01 and GX02 hereafter), were isolated from francolins, which are resident birds in southern China. GX01 and GX02 were characterized as velogenic NDVs. Based on the weaker pathogenicity of these viruses in chickens, the amino acid sequences of seven proteins from genotype XII NDVs were compared, which revealed 17, 40, 15, 7, 32, 25, and 31 variations in the NP, P, M, F, HN, L, and V proteins, respectively, some of which could be responsible for this decreased pathogenicity. Epidemiological and phylogenetic analyses suggest that subtype XIIb NDVs have multiple transmission chains, and that resident birds may be involved in this process as intermediate hosts in which viruses keep evolving. Because of the increased pathogenicity of subtype XIIb NDVs, the protective efficacy of GX01 as an inactivated vaccine was evaluated and compared with that of two commercial inactivated vaccines in chickens. The results showed that the subtype XIIb NDVs could be candidate genotype-matched vaccine strains against genotype XII NDVs.

RNA sequencing reveals CircRNA expression profiles in chicken embryo fibroblasts infected with velogenic Newcastle disease virus.

Newcastle disease virus (NDV) is an important avian pathogen prevalent worldwide; it has an extensive host range and seriously harms the poultry industry. Velogenic NDV strains exhibit high pathogenicity and mortality in chickens. Circular RNAs (circRNAs) are among the most abundant and conserved eukaryotic transcripts. They are part of the innate immunity and antiviral response. However, the relationship between circRNAs and NDV infection is unclear. In this study, we used circRNA transcriptome sequencing to analyze the differences in circRNA expression profiles post velogenic NDV infection in chicken embryo fibroblasts (CEFs). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to reveal significant enrichment of differentially expressed (DE) circRNAs. The circRNA- miRNA-mRNA interaction networks were further predicted. Moreover, circ-EZH2 was selected to determine its effect on NDV infection in CEFs. NDV infection altered circRNA expression profiles in CEFs, and 86 significantly DE circRNAs were identified. GO and KEGG enrichment analyses revealed significant enrichment of DE circRNAs for metabolism-related pathways, such as lysine degradation, glutaminergic synapse, and alanine, aspartic-acid, and glutamic-acid metabolism. The circRNA- miRNA-mRNA interaction networks further demonstrated that CEFs might combat NDV infection by regulating metabolism through circRNA-targeted mRNAs and miRNAs. Furthermore, we verified that circ-EZH2 overexpression and knockdown inhibited and promoted NDV replication, respectively, indicating that circRNAs are involved in NDV replication. These results demonstrate that CEFs exert antiviral responses by forming circRNAs, offering new insights into the mechanisms underlying NDV-host interactions.

Susceptibility and Pathogenesis of Eurasian Tree Sparrows Experimentally Inoculated with Velogenic Newcastle Disease Virus.

Wild-caught Eurasian tree sparrows (Passer montanus) were experimentally inoculated with genotype VII velogenic Newcastle disease virus (NDV) APMV1/chicken/Japan/Fukuoka-1/2004 to investigate the susceptibility and pathogenesis of infected sparrows. Intranasal inoculation of two groups with high or low doses of the virus resulted in the mortality of some birds in both groups on days 7-15 postinoculation. Neurologic signs, ruffled feathers, labored breathing, emaciation, diarrhea, depression, and ataxia were observed in a few birds that eventually succumbed to death. The inoculation of the higher viral load resulted in higher mortality and hemagglutination inhibition antibody detection rates. Tree sparrows that survived the 18-day observation period after inoculation exhibited no apparent clinical signs. Histologic lesions in dead birds were observed in the nasal mucosa, orbital ganglion, and central nervous system, accompanied by NDV antigens detected by immunohistochemistry. Viral inclusion bodies were rarely observed in the cytoplasm of neurons. NDV was isolated from the oral swab and brain of dead birds but not from other organs, including the lung, heart, muscle, colon, and liver. In another experimental group, tree sparrows were intranasally inoculated with the virus and then examined 1-3 days later to examine the early pathogenesis of the disease. Inoculated birds exhibited inflammation of the nasal mucosa with viral antigens, and virus was isolated from some oral swab samples on days 2 and 3 postinoculation. The results of the present study suggest that tree sparrows are susceptible to velogenic NDV, and the infection could be fatal, although some birds can exhibit asymptomatic or mild infection. The unique pathogenesis regarding the neurologic signs and viral neurotropism of velogenic NDV was characteristic in infected tree sparrows.

Effects of methanol leaf extract of Anacardium occidentale treatment on the hematology of chickens infected with velogenic Newcastle disease virus

Effects of methanol leaf extract of Anacardium occidentale treatment on the hematology of chickens infected with velogenic Newcastle disease virus