Analysis of avian disease transmission risk and prevention measures in China

Many zoonotic diseases are found in wild animals and present a serious risk to human health, in particularly the virus carried by birds flying freely around the world is hard to control. There are three main bird migration routes which cover the most areas of China. It is important to investigate and fully understand the types of avian transmitted diseases in key areas on the bird migration routines and its impacts on both birds and human health. However, no literature is available in how about the risk of virus carried by migrating birds, and how to predict and reduce this risk of virus spreading to human being so far. In this paper, we first reviewed the main pathogen types carried by birds, including coronaviruses, influenza viruses, parasites, Newcastle disease virus (NDV), etc., and then discussed the spread risk of avian viruses to human being and animals in key areas of biosafety prevention. We also analyzed and discussed the risk of cross-spread of diseases among different bird species in nature reserves located on bird migration routes which provide sufficient food sources for migratory birds and attract numerous birds. Diseases transmitted by wild birds pose a serious threat to poultry farms, where high density of poultry may become avian influenza virus (AIV) reservoirs, cause a risk of avian influenza outbreaks. Airports are mostly built in suburban areas or remote areas with good ecological environment. There are important transit places for bird migration and densely populated areas, which have serious risk of disease transmission. Finally, this paper puts forward the following prevention suggestions from three aspects. First, establish and improve the monitoring and prediction mechanism of migratory birds, and use laser technology to prevent contact between wild birds and poultry. Second, examine and identify virus types carried by birds in their habitats and carry out vaccination. Third, protect the ecological environment of bird habitat, and keep wild birds in their natural habitat, so as to reduce the contact between wild birds and human and poultry, and thus reduce the risk of virus transmission.

Which strain of the avian coronavirus vaccine will become the prevalent one in China next?

Infectious bronchitis virus (IBV) is a vital pathogen in poultry farms, which can induce respiratory, nephropathogenic, oviduct, proventriculus, and intestinal diseases. Based on the phylogenetic classification of the full-length S1 gene, IBV isolates have been categorized into nine genotypes comprising 38 lineages. GI (GI-1, GI-2, GI-3, GI-4, GI-5, GI-6, GI-7, GI-13, GI-16, GI-18, GI-19, GI-22, GI-28, and GI-29), GVI-1 and GVII-1 have been reported in China in the past 60 years. In this review, a brief history of IBV in China is described, and the current epidemic strains and licensed IBV vaccine strains, as well as IBV prevention and control strategies, are highlighted. In addition, this article presents unique viewpoints and recommendations for a more effective management of IBV. The recombinant Newcastle Disease virus (NDV) vector vaccine expressed S gene of IBV QX-like and 4/91 strains may be the dominant vaccine strains against NDV and IBV.

Viral diseases of poultry in Assam, India: a review

The Indian poultry market is estimated to have an annual growth rate of 8.1% as of today. However, infectious diseases in poultry pose an important constraint in the growth and development of this sector in our region. Among infectious diseases, viral diseases of poultry pose a serious threat to the poultry industry from an economic point of view. Several viral disease outbreaks have been reported by various researchers from different parts of the country. Among the common viral diseases of poultry, incidences of Newcastle disease, Avian Influenza, Fowl Pox, Infectious Bursal Disease, Marek's disease, Infectious Bronchitis, Infectious Laryngotracheitis and Inclusion Body Hepatitis are significant in Assam as well as other parts of India. Thorough epidemiological studies followed by the identification of different serotypes, pathotypes, strains, etc. by genotyping and molecular characterization of viral disease pathogens may lead to ways to control and eradicate the diseases. Importance should be given to maintaining basic preventive measures like biosecurity, farm hygiene, and proper vaccination. In a developing country like India, disease outbreaks can impact the country's economy. In this study, a brief view of the common viral disease of poultry and its diagnosis and control strategies in Assam, India is depicted. However, this review well indicates a plethora of avian diseases that have occurred over the years causing a severe impact on poultry farming as a whole.

Antiviral Potential of the Genus Panax: An updated review on their effects and underlying mechanism of action.

Viral infections are known as one of the major factors causing death. Ginseng is a medicinal plant that demonstrated a wide range of antiviral potential, and saponins are the major bioactive ingredients in the genus Panax with vast therapeutic potential. Studies focusing on the antiviral activity of the genus Panax plant-derived agents (extracts and saponins) and their mechanisms were identified and summarized, including contributions mainly from January 2016 until January 2022. P. ginseng, P. notoginseng, and P. quinquefolius were included in the review as valuable medicinal herbs against infections with 14 types of viruses. Reports from 9 extracts and 12 bioactive saponins were included, with 6 types of protopanaxadiol (PPD) ginsenosides and 6 types of protopanaxatriol (PPT) ginsenosides. The mechanisms mainly involved the inhibition of viral attachment and replication, the modulation of immune response by regulating signaling pathways, including the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway, phosphoinositide-dependent kinase-1 (PDK1)/ protein kinase B (Akt) signaling pathway, c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. This review includes detailed information about the mentioned antiviral effects of the genus Panax extracts and saponins in vitro and in vivo, and in human clinical trials, which provides a scientific basis for ginseng as an adjunctive therapeutic drug or nutraceutical.

Development of SARS-CoV-2 animal vaccines using a stable and efficient NDV expression system.

With the continuation of the coronavirus disease 2019 pandemic and the emergence of new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants, the control of the spread of the virus remains urgent. Various animals, including cats, ferrets, hamsters, nonhuman primates, minks, tree shrews, fruit bats, and rabbits, are susceptible to SARS-CoV-2 infection naturally or experimentally. Therefore, to avoid animals from becoming mixing vessels of the virus, vaccination of animals should be considered. In the present study, we report the establishment of an efficient and stable system using Newcastle disease virus (NDV) as a vector to express SARS-CoV-2 spike protein/subunit for the rapid generation of vaccines against SARS-CoV-2 in animals. Our data showed that the S and S1 protein was sufficiently expressed in rNDV-S and rNDV-S1-infected cells, respectively. The S protein was incorporated into and displayed on the surface of rNDV-S viral particles. Intramuscular immunization with rNDV-S was found to induce the highest level of binding and neutralizing antibodies, as well as strong S-specific T-cell response in mice. Intranasal immunization with rNDV-S1 provoked a robust T-cell response but barely any detectable antibodies. Overall, the NDV-vectored vaccine candidates were able to induce profound humoral and cellular immunity, which will provide a good system for developing vaccines targeting both T-cell and antibody responses.

Newcastle Disease Virus as a Vaccine Vector for SARS-CoV-2.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in more than 16 million infections and more than 600,000 deaths worldwide. There is an urgent need to develop a safe and effective vaccine against SARS-CoV-2. Currently, several strategies are being pursued to develop a safe and effective SARS-CoV-2 vaccine. However, each vaccine strategy has distinct advantages and disadvantages. Therefore, it is important to evaluate multiple vaccine platforms to select the most efficient vaccine platform for SARS-CoV-2. In this regard, Newcastle disease virus (NDV), an avian virus, has several well-suited properties for development of a vector vaccine against SARS-CoV-2. Here, we elaborate on the idea of considering NDV as a vaccine vector for SARS-CoV-2.

Antiviral properties of clove (Syzygium aromaticum)

Viruses are the leading causes of various viral infections in animals, including humans, ranging from mild to potentially fatal illnesses. Antiviral drugs or vaccines usually control these viral infections, but some viruses become resistant to antiviral drugs, demanding new antiviral remedies or cell-based antiviral therapies. Herbal medicines are usually targeting viral and cellular targets during viral replication. Interestingly, folk medicine has used clove as an essential herbal medication with promising antiviral and anti-inflammatory properties. Traditionally, clove extract, oil, or individual active ingredients (e.g., eugenol) have antithrombotic, immunostimulatory, and antibacterial effects, which may be additionally beneficial during severe viral infections. To these points, we aim in this chapter to discuss the potential broad-spectrum antiviral role of clove and its active constituents against emerging and re-emerging RNA and DNA viruses. © 2022 Elsevier Inc. All rights reserved.

Infection of Bone Marrow-Derived Mesenchymal Stem Cells with Virulent Newcastle Disease Virus Maximizes Cytokine Production: A Step Toward vNDV Immunotherapy

Newcastle Disease (ND) vaccines are being used for more than 7 decades, the disease is still a major challenge for poultry industry both locally and internationally. ND frequently emerges in highly vaccinated flocks causing high economic losses without specific treatment. Mesenchymal stem cells (MSCs) are a group of pluripotent cells with multiple biotechnology applications, including but not limited to tissue genesis, tissue repair, hematopoiesis, and immune modulation. Therapeutic strategies based on the usage of stem cells includes the cells either themselves or their secretions (secretome), which has recently shown ability to inhibit SARS-CoV2 replication in-vitro. In this study, MSCs were prepared from the bone marrow of native Egyptian Fayoumi chicken. The MSC with the surface marker CD105 (CD105+) were magnetically separated and infected with virulent Newcastle disease virus (vNDV). The virusinduced multiple changes at the cellular and ultrastructural level in the infected cells, and it was able to maximize the production of interferon-gamma (IFNγ) and interleukin 2 (IL2), interleukin 6 (IL6) and interleukin 12 (IL12). In conclusion, our data represent a preliminary step in vNDV immunotherapy where MSCs media could be used for the treatment of vNDV in infected flocks © 2022 by the authors. Licensee ResearchersLinks Ltd, England, UK

A phylogenetic perspective of antiviral species of the genus Artemisia (Asteraceae-Anthemideae): A proposal of anti SARS-CoV-2 (COVID-19) candidate taxa.

Introduction: Different classes of disease-causing viruses are widely distributed universally. Plant-based medicines are anticipated to be effective cures for viral diseases including the COVID-19, instigated by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). This study displays the phylogenetic perspective of Artemisia and proposes some candidate taxa against different viral diseases, including SARS-CoV-2. Methods: Data of Artemisia with antiviral activity were obtained from different published sources and electronic searches. A phylogenetic analysis of the nrDNA ITS sequences of reported antiviral Artemisia species, along with the reference species retrieved from the NCBI GenBank database, was performed using the maximum likelihood (ML) approach. Results: In total, 23 Artemisia species have been documented so far with antiviral activity for 17 different types of viral diseases. 17 out of 23 antiviral Artemisia species were included in the ITS phylogeny, which presented the distribution of these antiviral Artemisia species in clades corresponding to different subgenera of the genus Artemisia. In the resultant ML tree, 10 antiviral Artemisia species appeared within the subgenus Artemisia clade, 2 species appeared within the subgenus Absinthium clade, 3 species appeared within the subgenus Dracunculus clade, and 2 species appeared within the subgenus Seriphidium clade. Discussion: Artemisia species from different subgenera with antiviral activity are prevalent in the genus, with most antiviral species belonging to the subgenus Artemisia. A detailed analysis of taxa from all subgenera, particularly the subgenus Artemisia, is therefore proposed in order to discover compounds with potential anti-SARS-CoV-2 activity.

Feasibility and accuracy verification of respiratory virus detection by mask virus extraction

OBJECTIVE: To explore a new method for detecting respiratory viruses by extracting residual virus on mask, and verify its reliability and sensitivity. METHODS: The novel coronavirus analogs-s La Sota strains of chicken Newcastle disease virus and H120 strains of infectious bronchitis virus with different diluted concentrations were sprayed onto surgical masks and N95 masks through a respiratory simulator, and they were left standing at room temperature for 2 hours and 12 hours, respectively. The cDNA and its amplification cycle(CT) values of the nucleoocapsid protein(N) of chicken Newcastle disease virus and the nucleoprotein(NP) genes of infectious bronchitis virus were detected by ordinary polymerase chain reaction(PCR) and quantitative real-time PCR(qRT-PCR). The minimum detectable virus concentration and viral content in masks under different retention times were compared. RESULTS: The gene bands of the Newcastle disease virus La Sota strains and the infectious bronchitis virus H120 strains were detected on the masks stored for different times, and the total RNA of the virus had good amplification curves in the range of 10 pg-10 ng. The mean CT values of N gene and NP gene of the residual virus on the general medical surgical mask and N95 masks placed for 2 h were 22.547+or-0.342,23.698+or-0.501 and 22.855+or-0.308,24.036+or-0.338, respectively. However, only part of them could be detected after 12 h. respectively, and there was no significant difference in CT values between the two masks during the same period of time(P2 h=0.452, P12 h=0.355). The minimum detectable concentration of virus in the masks was 1:800, and the number of residual viruses on the mask that can be detected was 6.75x10~3. CONCLUSION: The method of screening coronavirus by detecting virus residues on masks within 2 hours was feasible and suitable for medical surgical masks and N95 masks, which can be used for preliminary screening of respiratory viruses.

Effects of harmful gases emitted from poultry houses on productive and health performance

Air pollution in the environment in which poultry is raised is one of the most serious problems facing the poultry sector across various aspects of production. Perhaps the most dangerous gas emitted from poultry houses is ammonia. The high concentrations of this gas in the air above the permissible limits (15 ppm) will have disastrous consequences. Ammonia directly affects the health and safety of birds, as it is a cause of ammonia blindness in birds accompanied by many respiratory diseases that destroy production and increase breeding costs. In addition, high concentrations of ammonia (above 20 ppm) contribute to enhancing the infection of birds with Newcastle and the bronchitis virus. In general, the greenhouse gases emitted from poultry houses included four main gases (carbon dioxide, nitrous oxide, methane and hydrogen sulphide). Studies regarding their direct effects on the health and productivity of birds have been insufficient. In the direct form, as the concentrations of greenhouse gases rise to very high limits, they cause suffocation and death., the behaviour of the greenhouse gases in the indirect effect is reflected being a source of nutritional stress and a group of diseases and parasites which lead to a decrease in productivity levels. The intensity and concentrations of gas emissions are directly related to many factors such as geographic location, the season of the year, ventilation technologies, humidity, litter quality, nutritional status and stocking density. The advances in ventilation technologies have played a key role in expelling all harmful gases, especially those that depend on negative pressure. However, greenhouse gases remain a real threat to the poultry industry in particular and to the planet's environment in general.

Prevalence of concurrent infections in broiler population of district Chakwal, Pakistan

Broiler population is one of the most important segments of livestock due to its significant contribution in white meat production. Infectious disease outbreaks adversely influence the production potential and consequently cause economic losses. Epidemiological data regarding magnitude of these disease outbreaks is of fundamental importance for planning of a comprehensive control strategy. With retrospective design, this study was conducted from January 2013 through December 2017 in order to assess the disease burden on broilers reared in different open type poultry houses. Out of total 658 commercial farms with capacity of 4221800 broilers, across Chakwal, a representative sample of 70 farms with capacity of 448000 broilers was randomly selected for collection and analysis of disease data. Five years' data of these randomly selected farms revealed highest (44.64%) crude morbidity during monsoon season followed by 23.92%, 22.12% and 17.49% for winter, spring and post-monsoon seasons respectively. The highest (14.90%) prevalence was recorded for new castle disease followed by infectious bursal disease (11.79%), pullorum disease (11.17%), colibacillosis (8.71%), infectious bronchitis (7.87%), inclusion body hepatitis (7.79%), chronic respiratory disease (7.67%), necrotic enteritis (6.48%), coccidiosis (6.09%), mycotoxicosis (5.43%), fowl cholera (4.74%), infectious coryza (4.41%), fowl typhoid (4.22%), omphalitis (3.71%) and hydropericardium syndrome (0.05%). Maximum share in crude morbidity was contributed by bacterial diseases with highest proportional morbidity of 48.68% followed by viral (40.32%), parasitic (5.80%) and fungal (5.20%) diseases. This epidemiological data represents true picture of study population and is a valuable tool for planning of prevention strategy and research priorities.

A review of pig and poultry diseases in the Eastern Cape province of South Africa, 2000-2020

The informal poultry and pig sector in the Eastern Cape Province (ECP) of South Africa is of significant socio-economic importance as it sustains livelihoods and ensures food security;yet little is known about the distribution and prevalence of infectious and zoonotic diseases in this region. This paper reviews data published for pig and poultry diseases in the province during the last 20 years (2000-2020). The review included relevant published papers identified by a computerised literature search from Web of Science;provincial animal health reports;the national database from the Department of Agriculture, Land Reform and Rural Development (DALRRD);animal health reports submitted by DALRRD to the World Organisation for Animal Health (OIE) via the World Animal Health Information Database (WAHID) interface and laboratory records. A publication was considered eligible if it included qualitative or quantitative information on any disease affecting pigs and poultry including zoonosis. The search retrieved 174 publications, of which 26 were relevant. The review found that Newcastle disease (ND), coccidiosis and fowl pox (FP) were the most reported avian diseases in the national database, whereas avian infectious bronchitis (AIB), ND and highly pathogenic avian influenza (HPAI) were the most reported diseases in the OIE database. Classical swine fever (CSF) was the most reported pig disease in both databases. The retrieved literature on pig and poultry diseases was scarce and no longer up to date, providing decision makers with little information. The review identified important zoonotic diseases that require further studies yet failed to find information on important neglected diseases like leptospirosis.

A systematic review and meta-analysis on global prevalence of infectious diseases in backyard chicken in the recent two decades

Backyard poultry is evolving as a fast-growing sector in recent times across the world. Apart from providing nutritional security, and livelihood to marginalized sector, also fulfils the demand for organic and welfare meat and eggs. However, the productivity is often challenged by incidences of diseases due to poor biosecurity and lack of vaccination. In this study, systematic review and meta-analysis were performed on the global prevalence of infectious diseases in backyard chickens. A total of 22 bacterial, viral, parasitic and fungal diseases were reported from 55 publications between 2000 and 2020 worldwide. Viral diseases were the most reported followed by bacterial and parasitic diseases. 61 out of 91 studies from 55 publications investigated seven major diseases: Avian influenza (AI), Newcastle disease (ND), infectious bronchitis (IB), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), Salmonella infection, and infectious laryngotracheitis (ILT). The overall pooled prevalence estimate for all the diseases worldwide was 33% (95% confidence interval (CI): 28-38). The pooled estimates for most reported viral diseases AI and ND were 12.5% (95% CI: 7-18) and (30% CI: 19-43), respectively. IBD (71% CI: 13-100), MS (76% CI: 67-85) and helminth infestations (72% CI: 44-93) were the highly prevalent diseases among viral, bacterial and parasitic infections, respectively. The continent wise pooled prevalence ranged from 17 to 32%. The present results will help in devising the best possible strategies to minimize the disease risk for commercial poultry and humans as well as for improving the productivity of backyard poultry farming.

The study of the antigenic properties of an experimental sample of inactivated combined vaccine against Newcastle disease and avian infectious bronchitis

The results of the study of the antigenic properties are presented for an experimental sample of emulsified inactivated vaccine against Newcastle disease (ND) and avian infectious bronchitis (IB) supplemented with acrylic acid copolymer (CoAA) as an additional stimulator of the immunogenesis (ND + IB+ CoAA / AB-M4). Experiments with vaccinated chicks evidenced that the experimental inactivated vaccine induces a higher level of immune response compared to the emulsified inactivated vaccine against ND and IB (ND + IB / AB-M4) manufactured according to the standard method.

"Fuzheng Quxie" and antiviral effect of Ganoderma (Lingzhi)

"Fuzheng Quxie" is an important theory of TCM related to prevention and cure of diseases. By enhancing the body immunity, Ganoderma (Lingzhi) indirectly inhibits the virus invasion, proliferation and destruction in the human body ("Fuzheng" means strengthening and consolidating body resistance). It can also directly inhibit and kill viruses ("Quxie" means dispelling evil). Lingzhi and its active components have antiviral effects on influenza virus, herpes virus, hepatitis B virus, human immunodeficiency virus, Newcastle disease virus, dengue virus and enterovirus. Lingzhi preparations alone or with antiviral drugs can treat hepatitis B, herpes zoster, recurrent genital herpes, condyloma acuminatum, infectious mononucleosis of children, cervical papillomavirus infection and AIDS. In addition, the possibility of preventing and treating COVID-19 (corona virus disease 2019) with Lingzhi was discussed.

Development and Scalable Production of Newcastle Disease Virus-Vectored Vaccines for Human and Veterinary Use.

The COVID-19 pandemic has highlighted the need for efficient vaccine platforms that can rapidly be developed and manufactured on a large scale to immunize the population against emerging viruses. Viral-vectored vaccines are prominent vaccine platforms that have been approved for use against the Ebola virus and SARS-CoV-2. The Newcastle Disease Virus is a promising viral vector, as an avian paramyxovirus that infects poultry but is safe for use in humans and other animals. NDV has been extensively studied not only as an oncolytic virus but also a vector for human and veterinary vaccines, with currently ongoing clinical trials for use against SARS-CoV-2. However, there is a gap in NDV research when it comes to process development and scalable manufacturing, which are critical for future approved vaccines. In this review, we summarize the advantages of NDV as a viral vector, describe the steps and limitations to generating recombinant NDV constructs, review the advances in human and veterinary vaccine candidates in pre-clinical and clinical tests, and elaborate on production in embryonated chicken eggs and cell culture. Mainly, we discuss the existing data on NDV propagation from a process development perspective and provide prospects for the next steps necessary to potentially achieve large-scale NDV-vectored vaccine manufacturing.

The effects of the composition and dispersion of the oil phase on the antigenicity of the associated inactivated vaccine against chicken infectious bronchitis, Newcastle disease, and egg drop syndrome-76

The antigenicity of three inactivated emulsified associated vaccines against viruses of chicken infectious bronchitis (IB), Newcastle disease (ND), and egg drop syndrome-76 (EDS-76) based on the oil adjuvant ISA-15 (O/W) was comparatively studied: (1) reference vaccine (IB+ND+EDS-76/ISA-15);(2) experimental vaccine (IB+NB+EDS-76/ISA-15-Nano) with a nanoscale-dispersed oil phase obtained by the use of a high-pressure homogenizer;(3) similar nano-scale vaccine (IB+NB+EDS-76+CoAA/ ISA-15-Nano) additionally supplemented with a copolymer of acrylic acid (CoAA). The in vivo tests of the vaccines on the chicks evidenced that both nano-scale vaccines enhanced the immune response in vaccinated chicks as compared to the reference vaccine and that supplementation with CoAA resulted in the highest postvaccinal antibody titers.

Decreased effectiveness of vaccination against infectious bronchitis as the result of increased incidence of vesicular enteritis in broilers

The incidence of infectious bronchitis (IB) in chickens has increased in Russian Federation during 2020- 2021 despite the widespread vaccination of the susceptible poultry. The effectiveness of vaccinations against IB virus and Newcastle disease can be significantly affected by vesicular enteritis (runting stunting syndrome) accompanied by malabsorption. The study presented demonstrated that virally induced malabsorption in broilers is accompanied by the synchronous decreases in the concentrations of magnesium and zinc in blood serum. Evaluation of the effectiveness of vaccination by RT-PCR for the presence of IB viral RNA in the intestine at day 2 after the vaccination indicates a sharp decrease in the PCR prevalence in individuals with vesicular enteritis and allows for the exclusion of possible population-wide decrease in post-vaccination immunity. When considering biochemical parameters as markers of organopathologies the population-based approach to data analysis should be applied.

An improved heamagglutination inhibition test for rapid diagnosis and stereotyping of avian infectious bronchitis virus

Infectious bronchitis virus (IBV) causes an acute, highly contagious viral respiratory disease in poultry with huge economic impact and extremely difficult to control due to its multiple serotypes. The disease could be prevented by rapid diagnosis either molecular or serological test. However, the later test is inexpensive such as heamagglutination inhibition test (HI), but IBV fail to give Heamagglutination (HA) reaction without pretreatment. Therefore, we designed this study for preparation of IBV antigen by treating with different enzymes for HA reaction. IBV local isolates were characterized by SDS-PAGE and RT-PCR. The indigenous isolate HA antigens were treated with different proteolytic enzymes trypsin, neuraminidase and phospholipase C. The prepared antigen were stored at -86oC and used for HA test. All antigen prepared by different enzyme were found to give significant HA titer up to 7 log2 . During stability test antigen prepared by phospholipase C were found most stable up to six month by giving constant 7 log2 HA titer, while neuraminidase induced antigen were stable up to five months (7 log2). Trypsin treated antigen were readily lost its activity from 7 log2 to 2 log2 after two months of incubation. During specificity test all antigens showed specific effect on IBV by eliciting agglutination of RBCs while other avian viruses avian influenza (AI), new castle disease virus (NDV) and infectious bursal disease virus (IBDV) were not affected by enzymatic inductions. Therefore, the antigen prepared by phospholipase C has been found to be more effective for HI test for rapid diagnosis of IBV during infection.