Overview of the immunological mechanisms in hepatitis B virus reactivation:Implications for disease progression and management strategies

Hepatitis B virus(HBV)reactivation is a clinically significant challenge in disease management.This review explores the immunological mechanisms underlying HBV reactivation,emphasizing disease progression and management.It delves into host immune responses and reactivation’s delicate balance,spanning innate and adaptive immunity.Viral factors’disruption of this balance,as are interac-tions between viral antigens,immune cells,cytokine networks,and immune checkpoint pathways,are examined.Notably,the roles of T cells,natural killer cells,and antigen-presenting cells are discussed,highlighting their influence on disease progression.HBV reactivation’s impact on disease severity,hepatic flares,liver fibrosis progression,and hepatocellular carcinoma is detailed.Management strategies,including anti-viral and immunomodulatory approaches,are critically analyzed.The role of prophylactic anti-viral therapy during immunosuppressive treatments is explored alongside novel immunotherapeutic interventions to restore immune control and prevent reactivation.In conclusion,this compre-hensive review furnishes a holistic view of the immunological mechanisms that propel HBV reactivation.With a dedicated focus on understanding its implic-ations for disease progression and the prospects of efficient management stra-tegies,this article contributes significantly to the knowledge base.The more profound insights into the intricate interactions between viral elements and the immune system will inform evidence-based approaches,ultimately enhancing disease management and elevating patient outcomes.The dynamic landscape of management strategies is critically scrutinized,spanning anti-viral and immunomodulatory approaches.The role of prophylactic anti-viral therapy in preventing reactivation during immunosuppressive treatments and the potential of innovative immunotherapeutic interventions to restore immune control and proactively deter reactivation.

Partial Fusion (F) Gene Analysis of Newcastle Disease Virus Detected in Pakistan during 2021-2022

Newcastle disease (ND) virus is a leading threat to commercial and domestic poultry in Pakistan. The virus infects and constitutes irreversible impairment to the nervous system, damages the respiratory system, and marks severe gastrointestinal lesions leading to heavy mortality in short-living birds and substantial losses in layers and breeders. The continuous emergence and evolution of the virus made it inclined to evade the humoral response and indirectly the circumvention of artificial active immunization. Newcastle disease is caused by the orthoavula genus of the paramyxoviridae family and has shown high genetic diversity even in their genotypes while information regarding enzootic trends of the virus is scanty in Pakistan. A total of 40 tracheal samples of NDV were collected from different commercial broiler farms and 11 isolates of NDV were identified. In the current study, we determined the genetic diversity of the Newcastle disease virus based on the partial sequencing of the fusion protein gene available in the NCBI database. Genetic analysis showed that seven isolates belonged to class I genotype VII and four belonged to class II genotype II. Interestingly, two isolates had epidemiological connections with vaccine-like class II genotype II. Our findings, concerning the recent outbreaks of class I genotype VII and class II genotype II of NDV in vaccinated commercial flocks, suggest possible potential partial mutations in the fusion protein gene. Genetic diversity and formation of the new cleavage site in an important neutralizing protein of wild strain are linked with the potency of artificial active immunization and a major cause of vaccine failure.

Analysis of Occurrence and Mixed Infection of Sugarcane Bacilliform Virus Disease in Hainan Sugarcane-growing Area

[Objectives]The paper was to explore the occurrence and mixed infection of sugarcane bacilliform virus disease in Hainan sugarcane-growing area.[Methods]A total of 348 sugarcane leaf samples were collected from 7 sugarcane-growing areas in Hainan Province.Molecular detection of sugarcane bacilliform virus(SCBV)was carried out by PCR using specific primers.[Results]SCBV was detected in 244 out of 348 sugarcane samples,with an average detection rate of 70.11%.The highest detection rate was 76.66%in the Danzhou sugarcane-growing area,while the lowest was 57.14%in the Baisha sugarcane-growing area.The SCBV-positive samples were subjected to testing for SCYLV,SCSMV,SrMV,and SCMV,respectively.The results indicated that 106 out of 244 positive samples exhibited a single infection with SCBV,while 138 samples exhibited mixed infections with SCBV and other sugarcane viruses.The proportion of mixed infections among the SCBV-positive samples was as high as 56.56%.Among the various types of mixed infections,two-virus and three-virus mixed infections were the most prevalent.[Conclusions]SCBV has emerged as a significant threat to the secure production of sugarcane in the Hainan sugarcane-growing region.It presents an explosive infection in the Hainan sugarcane-growing region and frequently combines with other sugarcane viruses to infect sugarcane.The findings of this study will provide a theoretical foundation for the prevention and control of sugarcane bacilliform virus disease.

Current status of liver transplantation for human immunodeficiency virus-infected patients in China's Mainland

According to the report from the Chinese Center for Disease Control and Prevention,the prevalence of human immunodeficiency virus(HIV)infection exceeded 1.2 million individuals by the year 2022,with an annual increase of about 80000 cases.The overall prevalence of hepatitis B surface antigen among individuals co-infected with HIV reached 13.7%,almost twice the rate of the general population in China.In addition to the well-documented susceptibility to opportunistic infections and new malignancies,HIV infected patients frequently experience liver-related organ damage,with the liver and kidneys being the most commonly affected.This often leads to the development of end-stage liver and kidney diseases.Therefore,organ transplantation has emerged as an important part of active treatment for HIV infected patients.However,the curative effect is not satisfactory.HIV infection has been considered a contraindication for organ transplantation.Until the emergence of highly active anti-retroviral therapy in 1996,the once intractable replication of retrovirus was effectively inhibited.With prolonged survival,the failure of important organs has become the main cause of death among HIV patients.Therefore,transplant centers worldwide have resu-med exploration of organ transplantation for HIV-infected individuals and reached a positive conclusion.This study provides an overview of the current landscape of HIV-positive patients receiving liver transplantation(LT)in main-land China.To date,our transplant center has conducted LT for eight end-stage liver disease patients co-infected with HIV,and all but one,who died two months postoperatively due to sepsis and progressive multi-organ failure,have survived.Comparative analysis with hepatitis B virus-infected patients during the same period revealed no statistically significant differences in acute rejection reactions,cytomegalovirus infection,bacteremia,pulmonary infections,acute kidney injury,new-onset cancers,or vascular and biliary complications.

Outcomes of ABO-incompatible liver transplantation in end-stage liver disease patients co-infected with hepatitis B and human immunodeficiency virus

BACKGROUND Human immunodeficiency virus(HIV)-positive patients coinfected with hepatitis B virus(HBV)are eligible for liver transplantation(LT)in Africa and Southeast Asia,particularly China.However,the outcome of HIV-HBV coinfected patients referred for ABO-incompatible LT(ABOi-LT)is unknown.AIM To clarify the outcome of ABOi-LT for HIV-HBV coinfected patients with endstage liver disease(ESLD).METHODS We report on two Chinese HIV-HBV coinfected patients with ESLD who underwent A to O brain-dead donor LT and reviewed the literature on HIV-HBV coinfected patients treated with ABO-compatible LT.The pretransplantation HIV viral load was undetectable,with no active opportunistic infections.Induction therapy consisted of two sessions of plasmapheresis and a single dose of rituximab in two split doses,followed by an intraoperative regimen of intravenous immunoglobulin,methylprednisolone,and basiliximab.Post-transplant maintenance immunosuppressive agents consisted of tacrolimus and mycophenolate mofetil,and prednisone.RESULTS At the intermediate-term follow-up,patients showed undetectable HIV viral load,CD4(+)T cell counts greater than 150 cells/μL,no HBV recurrence,and stable liver function.A liver allograft biopsy showed no evidence of acute cellular rejection.Both patients survived at 36-42 mo of follow-up.CONCLUSION This is the first report of ABOi-LT in HIV-HBV recipients with good intermediate-term outcomes,suggesting that ABOi-LT may be feasible and safe for HIV-HBV coinfected patients with ESLD.

Liver biopsy in the post-hepatitis C virus era in Japan

In Japan,liver biopsies were previously crucial in evaluating the severity of hepatitis caused by the hepatitis C virus(HCV)and diagnosing HCV-related hepatocellular carcinoma(HCC).However,due to the development of effective antiviral treatments and advanced imaging,the necessity for biopsies has significantly decreased.This change has resulted in fewer chances for diagnosing liver disease,causing many general pathologists to feel less confident in making liver biopsy diagnoses.This article provides a comprehensive overview of the challenges and potential solutions related to liver biopsies in Japan.First,it highlights the importance of considering steatotic liver diseases as independent conditions that can coexist with other liver diseases due to their increasing prevalence.Second,it emphasizes the need to avoid hasty assumptions of HCC in nodular lesions,because clinically diagnosable HCCs are not targets for biopsy.Third,the importance of diagnosing hepatic immune-related adverse events caused by immune checkpoint inhibitors is increasing due to the anticipated widespread use of these drugs.In conclusion,pathologists should be attuned to the changing landscape of liver diseases and approach liver biopsies with care and attention to detail.

Influence of nonalcoholic fatty liver disease on response to antiviral treatment in patients with chronic hepatitis B:A meta-analysis

BACKGROUND Although hepatitis B virus infection is the leading cause of chronic liver injury globally,nonalcoholic fatty liver disease(NAFLD)is gradually gaining attention as another major chronic liver disease.The number of patients having chronic hepatitis B(CHB)with concomitant hepatic steatosis has increased.AIM To analyze the effect of NAFLD on the response to antiviral treatment in patients with CHB.METHODS Relevant English studies were systematically searched across PubMed,EMBASE,Web of Science,and Cochrane Library until October 2023.Studies in which the treatment outcomes were compared between patients with CHB only and those with CHB and hepatic steatosis were included.RESULTS Of the 2502 retrieved studies,11 articles were finally included.Biochemical response until 48 wk(OR=0.87,95%CI:0.50–1.53,P=0.000)and 96 wk(OR=0.35,95%CI:0.24–0.53,P=0.24)and virological response until 96 wk(OR=0.80,95%CI:0.43–1.49,P=0.097)were lower in patients with hepatic steatosis than in patients with CHB alone.CONCLUSION Hepatic steatosis lowers the biochemical response to antiviral treatment in patients with CHB.

Hepatitis A virus-associated acute acalculous cholecystitis in an adult-onset Still’s disease patient:A case report and review of the literature

BACKGROUND Acute acalculous cholecystitis(AAC)is inflammation of the gallbladder without evidence of calculi.Although rarely reported,its etiologies include hepatitis virus infection(e.g.,hepatitis A virus,HAV)and adult-onset Still’s disease(AOSD).There are no reports of HAV-associated AAC in an AOSD patient.CASE SUMMARY Here we report a rare case of HAV infection-associated AAC in a 39-year-old woman who had a history of AOSD.The patient presented with an acute abdomen and hypotension.Elevated hepatobiliary enzymes and a thickened and distended gallbladder without gallstones on ultrasonography suggested AAC,but there were no signs of anemia nor thrombocytopenia.Serological screening revealed anti-HAV IgM antibodies.Steroid treatment did not alleviate her symptoms,and she was referred for laparoscopic cholecystectomy.The resected gallbladder was hydropic without perforation,and her clinical signs gradually improved after surgery.CONCLUSION AAC can be caused by HAV in AOSD patients.It is crucial to search for the underlying etiology for AAC,especially uncommon viral causes.

Perilipin 2 inhibits replication of hepatitis B virus deoxyribonucleic acid by regulating autophagy under high-fat conditions

Hepatitis B virus(HBV)infection poses a global health concern without a definitive cure;however,antiviral medications can effectively suppress viral replication.This study delves into the intricate interplay between lipid metabo-lism and HBV replication,implicating molecular mechanisms such as the stearoyl coenzyme A desaturase 1 autophagy pathway,SAC1-like phosphatidylinositol phosphatase,and galectin-9 mediated selective autophagy of viral core proteins in regulating HBV replication.Within lipid droplets,perilipin 2(PLIN2)emerges as a pivotal guardian,with its overexpression protecting against autophagy and downregulation stimulating triglyceride catabolism through the autophagy pathway.This editorial discusses the correlation between hepatic steatosis and HBV replication,emphasizing the role of PLIN2 in this process.The study underscores the multifaceted roles of lipid metabolism,autophagy,and perilipins in HBV replication,shedding light on potential therapeutic avenues.

Hepatitis B virus infection in patients with Wilson disease:A large retrospective study

BACKGROUND Wilson disease(WD)is the most common genetic metabolic liver disease.Some studies have shown that comorbidities may have important effects on WD.Data on hepatitis B virus(HBV)infection in patients with WD are limited.AIM To investigate the prevalence and clinical impact of HBV infection in patients with WD.METHODS The clinical data of patients with WD were analyzed retrospectively,and the data of patients with concurrent WD and HBV infection were compared with those of patients with isolated WD.RESULTS Among a total of 915 WD patients recruited,the total prevalence of current and previous HBV infection was 2.1%[95%confidence interval(CI):1.2%-3.0%]and 9.2%(95%CI:7.3%-11.1%),respectively.The main finding of this study was the identification of 19 patients with concurrent WD and chronic hepatitis B(CHB)infection.The diagnosis of WD was missed in all but two patients with CHB infection.The mean delay in the diagnosis of WD in patients with concurrent WD and CHB infection was 32.5 mo,which was significantly longer than that in patients with isolated WD(10.5 mo).The rates of severe liver disease and mortality in patients with concurrent WD and CHB infection were significantly higher than those in patients with isolated WD(63.1%vs 19.3%,P=0.000 and 36.8%vs 4.1%,P<0.001,respectively).Binary logistic regression analysis revealed a significantly higher risk of severe liver disease at the diagnosis of WD in patients with current HBV infection[odds ratio(OR)=7.748;95%CI:2.890-20.774;P=0.000)]or previous HBV infection(OR=5.525;95%CI:3.159-8.739;P=0.000)than in patients with isolated WD.CONCLUSION The total prevalence of current HBV infection in patients with WD was 2.1%.The diagnosis of WD in CHB patients is usually missed.HBV infection is an independent risk factor for severe liver disease in WD patients.The diagnosis of WD should be ruled out in some patients with CHB infection.

Global Epidemic of Ebola Virus Disease and the Importation Risk into China: An Assessment Based on the Risk Matrix Method

Objective To analyze the global epidemic status of the Ebola virus disease(EVD) and assess the importation risk into China.Methods Data from World Health Organization reports were used. We described the global epidemic status of EVD from 1976–2021, and assessed and ranked the importation risk of EVD from the diseaseoutbreaking countries into China using the risk matrix and Borda count methods, respectively.Results From 1976–2021, EVD mainly occurred in western and central Africa, with the highest cumulative number of cases(14,124 cases) in Sierra Leone, and the highest cumulative fatality rate(85%) in the Congo. Outbreaks of EVD have occurred in the Democratic Republic of the Congo and Guinea since 2018. The importation risk into China varies across countries with outbreaks of disease.The Democratic Republic of the Congo had an extremely high risk(23 Borda points), followed by Guinea and Liberia. Countries with a moderate importation risk were Nigeria, Uganda, Congo, Sierra Leone,Mali, and Gabon, while countries with a low importation risk included Sudan, Senegal, and Co te d’Ivoire.Conclusion China is under the risk of EVD importation with the globalization and severe epidemic status of EVD. Key attention need to be paid to the Democratic Republic of the Congo, Guinea, and Liberia. Therefore, it is necessary to prevent and prepare in advance for importation risk in China.

Characterisation and separation of infectious bursal disease virus-like particles using aqueous two-phase systems

Infectious bursal disease(IBD)causes considerable economic losses in the commercial poultry industry worldwide.The principal way to control IBD virus(IBDV),the causative agent of IBD,is still through vaccination programs.Virus-like particles(VLPs)are recognised as a safe and potent recombinant vaccine platform.This research work explores the characterisation and separation of infectious bursal disease virus-like particles(IBD-VLPs)from crude feedstock.Various characteristics were studied with highperformance size-exclusion chromatography(HP-SEC),sodium dodecyl sulphate–polyacrylamide gel electrophoresis(SDS-PAGE)and transmission electron microscopy(TEM)analyses.Subsequently,the separation of IBD-VLPs using polyethylene glycol(PEG)/sodium citrate-based aqueous two-phase systems(ATPSs)was conducted and optimised.Moreover,a scale-up study of the best ATPS constituted of 15%PEG 6000,11%sodium citrate and 10%crude feedstock was performed to compare the separation performance of IBD-VLPs with and without centrifugation-assisted.The results indicated that the optimised ATPS with centrifugation-assisted for both 5 g and 50 g systems showed good recovery of IBDVLPs of>97%in the interphase between the PEG-rich top and salt-rich bottom phases.These optimised systems also showed high removal efficiencies of impurities of>95%.The results demonstrated that aqueous two-phase extraction could be a promising technology for efficient VLPs separation.

Positive correlation between latent Epstein-Barr virus infection and severity of illness in inflammatory bowel disease patients

BACKGROUND Emerging studies indicate the critical involvement of microorganisms,such as Epstein-Barr virus(EBV),in the pathogenesis of inflammatory bowel disease(IBD).Immunosuppressive therapies for IBD can reactivate latent EBV,complicating the clinical course of IBD.Moreover,the clinical significance of EBV expression in B lymphocytes derived from IBD patients’intestinal tissues has not been explored in detail.AIM To explore the clinical significance of latent EBV infection in IBD patients.METHODS Latent EBV infection was determined by double staining for EBV encoded RNA and CD20 in colon specimens of 43 IBD patients who underwent bowel resection.Based on the staining results,the patients were divided into two groups,according to their latent EBV infection states-negative(n=33)and positive(n=10).Illness severity of IBD were assigned according to Crohn’s disease activity index(ulcerative colitis)and Mayo staging system(Crohn’s disease).The clinicpathological data were analyzed between the two different latent EBV groups and also between the mild-to-moderate and severe disease groups.RESULTS Systolic pressure(P=0.005),variety of disease(P=0.005),the severity of illness(P=0.002),and pre-op corticosteroids(P=0.025)were significantly different between the EBV-negative and EBV-positive groups.Systolic pressure(P=0.001),variety of disease(P=0.000),pre-op corticosteroids(P=0.011)and EBV infection(P=0.003)were significantly different between the mild-to-moderate and severe disease groups.CONCLUSION IBD patients with latent EBV infection may manifest more severe illnesses.It is suggested that the role of EBV in IBD development should be further investigated,latent EBV infection in patients with serious IBD should be closely monitored,and therapeutic course should be optimized.

Study on Control Techniques of Virus Diseases in Facility Cherry

The diseases of sweet cherry caused by viruses and viroids have occurred in the main cherry producing areas of China and are increasing year by year, which has become an important factor affecting the yield and quality of sweet cherry. For this reason, this paper elaborated the prevention and countermeasures of virus diseases from six aspects, including soil treatment, cultivation of disease-free seedlings, prevention of disease and pest damage, reasonable pruning, water management, and treatment of virus diseases, in order to provide technical guidance for the disease resistance, high quality and high yield of facility cherry, as well as information reference for the further improvement of the technical system of virus disease prevention and cultivation of facility cherry.

Crohn’s disease in human immunodeficiency virus-infected patient:A case report

BACKGROUND Inflammatory bowel disease(IBD)is an autoimmune condition treated with immunosuppressive drugs.However,the need for immune system suppression becomes questionable when infection with the human immunodeficiency virus(HIV)occurs simultaneously and impacts the course of IBD.Our reported case represents the clinical course,prescribed treatment and its effect,as well as clinical challenges faced by physicians in a combination of such diseases.We also present a comprehensive literature review of similar cases.CASE SUMMARY A 49-year-old woman suffering from a newly diagnosed Crohn’s disease was hospitalized due to exacerbated symptoms(abdominal pain,fever,and weight loss).During her hospital stay,she tested positive for HIV.With conservative treatment,the patient improved and was discharged.In the outpatient clinic,her HIV infection was confirmed as stage C3,and antiretroviral treatment was initiated immediately.That notwithstanding,soon the patient was rehospitalized with pulmonary embolism and developed a series of complications because of the subsequent coexistence of IBD and HIV.After intensive and meticulous treatment,the patient’s condition has improved and she remains in remission.CONCLUSION The paucity of studies and data on the coexistence of HIV and IBD leaves clinicians doubting the optimal treatment options.

A review of inherent beneficial effects of black seeds(Nigella sativa)in Marburg virus disease management

Background:In the management of patients with MARV infection,this review article focuses on the potential protective effects of black seeds(Nigella sativa).Methods:To find studies that evaluated various effects of black seeds(N.sativa)related to signs and symptoms of MARV infection,reference lists and databases such as Medline/Pubmed/PMC,Google Scholar,Science Direct,Ebsco,Scopus,Web of Science,and Embase were searched.Results:In numerous clinical,animal,in-vitro,in-vivo,and in-ovo studies,black seeds(N.sativa)have demonstrated potential antiviral,anti-inflammatory,antioxidant,immunomodulatory,and hepatoprotective properties that may aid in the treatment of MARV-infected patients.Conclusion:In the initial generalization phase of MARV infection,patients may use black seeds(N.sativa)as an adjunctive therapy in addition to symptomatic treatment and supportive care.Future randomized controlled clinical trials would confirm N.sativa’s efficacy and safety in MARV-infected patients.

Genomic Sequencing and Molecular Characteristics of A Very Virulent Strain of Infectious Bursal Disease Virus Isolated in China

[Objective] The paper was to determine the genomic sequence of a very virulent strain of infectious bursal disease virus（IBDV）,and study its molecular characteristics.[Method] A very virulent strain（vvIBDV）（HLJ-0504） of infectious bursal disease virus（IBDV） with special characters was isolated in China and its genome was sequenced.[Result] Sequence analysis showed that segment A of HLJ-0504 was derived from vvIBDV,while segment B was from a distinct ancestor.The morbidity and mortality of HLJ-0504 was 100% and 86.7%to SPF chickens,respectively.[Conclusion] vvIBDV with distinct segment B were still circulating and the evolution of IBDV was diversified in China.Besides,it is hard to imagine that the virulence of IBDV is determined solely by segment A or B.

Cloning and Prokaryotic Expression of VP1 Gene of Foot-and-Mouth Disease Virus (FMDV) Type O

According to the complete genome of foot-and-mouth disease virus(FMDV)type O,a pair of special primers was designed to amplify VP1 gene.The VP1 gene was amplified by RT-PCR and subsequently inserted into the expression vector pGEX-6p-1 and induced by IPTG.Then SDS-PAGE showed the expressed protein was 51 kD in molecular weight.Then the product was purified by GSTrap FF columns.The product was detected through Western-blot that showed the protein has antigenicity.It provided fundamental data and materials for further investigation on diagnosis method of FMDV.

Screening of Anti-Newcastle Disease Virus Ingredients of Phyllanthus urinaria

[ Objective ] The aim of the study was to screen the antiviral ingredients of Chinese herbal medicine Phyllanthus urinaria in order to devel- op new drugs for the treatment of viral diseases of poultry. [ Method ] The whole grass of phyllanthus was respectively decocted in 75% ethanol （E） and pure water （PF）, and then the active ingredients were separately extracted in petroleum ether （PE）, ethyl acetate （EA）, and n-butyl alcohol （BU）. The extracts were inoculated on chicken embryo fibroblast （CEF） to observe their inhibitory effect on cytopathic effect （CPE） of Newcastle disease virus （NDV）, inoculated into chicken embryos to observe the changes of the hemagglutination titer of NDV, and inoculated in chickens to determine the mortality and evaluate their effect of immune protection. [ Result] The E -PE and E -BU extracts, especially E -BU extract, inhibi- ted CPE of NDV on CEF and significantly inhibited the proliferation of NDV in chicken embryo （P〈0.05） ; the survival rate of E-PE and E-BU group was extremely significantly higher than that of ribavirin group and the normal saline control （ P 〈0.01 ）, with E - PE group more higher. [ Condusion] The water extract of phyllanthus is less effective; E -PE extract and E -BU extract should effectively inhibit the CPE and proliferation in chicken embryo of NDV and also have better immune protection against NDV.

Genetic Analysis of the VP2 Hypervariable Region of Thirty-six Infectious Bursal Disease Virus Isolates in China during 2009-2012

[Objective] Infectious bursal disease （IBD） is a highly contagious immuno- suppressive disease caused by infectious bursal disease virus （IBDV）. IBDV is ge- netically prone to mutation, which results in challenges to the disease prevention and control. Thus, it is necessary to continuously monitor the prevalence of IBDV. [Method] 36 IBDVs were identified from ten provinces in China from 2009 to 2012. Partial fragments of VP2, including the hypervariable region （HVR）, from new iso- lates were sequenced and analyzed through comparisons with published sequences of IBDV, including 18 strains isolated previously by our lab and 24 reference strains from China and around the world. [Result] Phylogenetic analysis showed a co-exis- tence of IBDV strains belonging to classic, variant, attenuated, and very virulent IB- DV （wlBDV） in China. wlBDVs remain the predominant strains in China and the new subgroup was emerging. Alignment analysis revealed several distinct amino acid mutations that might be involved in virulence or antigenicity variation. [Conclu- sion] The results offered evolutionary clues showing the emerging trend of obvious variations and diversity of IBDV in major poultry-producing regions of China particu- larly in recent years. These findings will contribute to a better understanding of the genetic evolution of IBDV.