scholarly journals Occurrence of Marek's disease in vaccinated Algerian broiler breeder flocks: A histopathological survey

2021 ◽  
pp. 3021-3027
Author(s):  
Lounas Abdelaziz ◽  
Besbaci Mohamed ◽  
Akkou Madjid ◽  
Tali Oumennoune
Keyword(s):  
Color Change ◽  
Clinical Symptoms ◽  
Histopathological Examination ◽  
Lymphoproliferative Disease ◽  
Marek's Disease ◽  
Control Measures ◽  
Marek’S Disease ◽  
Broiler Breeder ◽  
Blast Cells ◽  
And Control

Background and Aim: Marek's disease (MD) is a lymphoproliferative disease that occurs in chickens. In the absence of control measures, MD causes devastating losses to commercial poultry flocks. Vaccination has enabled dramatic success in the prevention and control of MD. However, the MD vaccination program has failed frequently, and occasional clinical outbreaks have been reported in the vaccinated flocks as well. The present study aimed to describe the clinical and histopathological characteristics of the field cases of MD in broiler breeder flocks. Materials and Methods: A survey on the update of MD occurrence in Algerian broiler breeder flocks was conducted from June 2020 to September 2020. Ten vaccinated broiler breeder flocks located in Central Algeria and having progressive tumors in different visceral organs were evaluated for MD virus infection by conducting a histopathological examination of the birds. Results: The age of the birds affected with MD ranged from 13 to 22 weeks. The mortality rate varied sensitively from 4% to 10%. The clinical symptoms reported in the affected flocks included locomotor, nervous, digestive, and respiratory symptoms. Necropsy of the dead or euthanized birds revealed visceral lymphomatosis in several organs and macroscopic changes in the peripheral nerves (including loss of longitudinal striation, color change [grayish], and volume increase). The histopathological findings included the infiltration and proliferation of lymphocytes and blast cells (lymphoblasts) in various organs of the birds, which are the typical characteristics of MD and, therefore, confirmed the field infection of MD in these birds. Conclusion: The present study provided evidence for the high prevalence of MD in the broiler breeder flocks vaccinated with a bivalent vaccine (turkey herpesvirus+Rispens) at the hatchery. The findings of the present study may indicate highlevel failure of vaccination in these birds.

scholarly journals Depletion of CD8αβ+ T Cells in Chickens Demonstrates Their Involvement in Protective Immunity towards Marek’s Disease with Respect to Tumor Incidence and Vaccinal Protection

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 557
Author(s):  
Supawadee Umthong ◽  
John R. Dunn ◽  
Hans H. Cheng
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Protective Immunity ◽  
Lymphoproliferative Disease ◽  
Tumor Formation ◽  
Marek's Disease ◽  
Control Measures ◽  
Marek’S Disease ◽  
Cell Mediated Immune Response

Marek’s disease (MD) is a lymphoproliferative disease in chickens caused by Marek’s disease virus (MDV), a highly oncogenic alphaherpesvirus. Since 1970, MD has been controlled through widespread vaccination of commercial flocks. However, repeated and unpredictable MD outbreaks continue to occur in vaccinated flocks, indicating the need for a better understanding of MDV pathogenesis to guide improved or alternative control measures. As MDV is an intracellular pathogen that infects and transforms CD4+ T cells, the host cell-mediated immune response is considered to be vital for controlling MDV replication and tumor formation. In this study, we addressed the role of CD8+ T cells in vaccinal protection by widely-used monovalent (SB-1 and HVT) and bivalent (SB-1+HVT) MD vaccines. We established a method to deplete CD8+ T cells in chickens and found that their depletion through injection of anti-CD8 monoclonal antibodies (mAb) increased tumor induction and MD pathology, and reduced vaccinal protection to MD, which supports the important role of CD8+ T cells for both MD and vaccinal protection.

Electron Microscopy of a Herpesvirus Isolated from Marek's Disease in Duck and Chicken Embryo Fibroblast Cultures

1968 ◽  
Vol 26 ◽  
pp. 222-223 ◽  
Author(s):  
Keyvan Nazerian
Keyword(s):  
Inclusion Bodies ◽  
Chicken Embryo Fibroblast ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Duck Embryo Fibroblast ◽  
Multinucleated Cells ◽  
Viral Particles ◽  
Infected Cells ◽  
And Control ◽  
Do So

A herpes-like virus has been isolated from duck embryo fibroblast (DEF) cultures inoculated with blood from Marek's disease (MD) infected birds. Cultures which contained this virus produced MD in susceptible chickens while virus negative cultures and control cultures failed to do so. This and other circumstantial evidence including similarities in properties of the virus and the MD agent implicate this virus in the etiology of MD.Histochemical studies demonstrated the presence of DNA-staining intranuclear inclusion bodies in polykarocytes in infected cultures. Distinct nucleo-plasmic aggregates were also seen in sections of similar multinucleated cells examined with the electron microscope. These aggregates are probably the same as the inclusion bodies seen with the light microscope. Naked viral particles were observed in the nucleus of infected cells within or on the edges of the nucleoplasmic aggregates. These particles measured 95-100mμ, in diameter and rarely escaped into the cytoplasm or nuclear vesicles by budding through the nuclear membrane (Fig. 1). The enveloped particles (Fig. 2) formed in this manner measured 150-170mμ in diameter and always had a densely stained nucleoid. The virus in supernatant fluids consisted of naked capsids with 162 hollow, cylindrical capsomeres (Fig. 3). Enveloped particles were not seen in such preparations.

ESTIMATION OF SARS-COV-2 SPECIFIC ANTIBODIES SEROPREVALENCE IN HEALTHCARE WORKERS IN DISTRICT UDAIPUR, INDIA

2021 ◽  
pp. 61-63
Author(s):  
Shelesh Kumar Swami ◽  
Nitesh Kumar Chauhan ◽  
Shuchi Goyal ◽  
A.K. Verma ◽  
Shweta Biyani
Keyword(s):  
Healthcare Workers ◽  
Clinical Symptoms ◽  
Control Measures ◽  
Rt Pcr ◽  
High Seroprevalence ◽  
Know How ◽  
Novel Coronavirus ◽  
And Control ◽  
Infection Eradication ◽  
Cumulative Prevalence

Background:Current pandemic caused by Novel coronavirus (COVID-19) causes clinical symptoms from fever to acute respiratory distress syndrome but may remain mild or asymptomatic. To evaluate the cumulative prevalence of SARSCoV-2 infection in a community and know how immune response develops in the population, reliable assay alongwith RT-PCR for detection of SARS-CoV 2 antibodies is needed. Healthcare workers (HCWs) represent a high-risk populat - ion for infection with SARS-CoV-2. Methods: We evaluated total antibodies recognizing the SARS CoV 2 receptor binding domain (S1-RBD) - - - or the Spike protein over a period of six months in a total of 310 healthcare workers engaged in hospital using SARS-CoV-2 Total antibody assay kit. Findings: The overall seroprevalence found in our analysis was 41.93%. In case of males the percentage positive was found to be signicantly higher at 43.91%, compared to females at 36.25%. Seroprevalence was signicantly higher in 50 years above age group in comparison to 20-50 years old aged healthcare workers. The seroprevalence was higher in doctors, nursing staff and lab technicians than other healthcare professionals as 44.6%. Conclusions: This study showed high seroprevalence of SARS-CoV-2 in healthcare workers which means remaining proportion of the healthcare workers are still susceptible to the infection. Good compliance to infection eradication and control measures, adequate PPEs, and early detection and isolation of healthcare workers infected with SARS-CoV-2 are mandatory to reduce the risk of SARS-CoV-2 infection.

scholarly journals The Emergence of a vv + MDV Can Break through the Protections Provided by the Current Vaccines

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1048
Author(s):  
Meng-ya Shi ◽  
Min Li ◽  
Wei-wei Wang ◽  
Qiao-mu Deng ◽  
Qiu-hong Li ◽  
...  
Keyword(s):  
Body Weight Gain ◽  
Challenge Test ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Large Area ◽  
Broiler Breeder ◽  
Reduced Body ◽  
Programmed Death ◽  
Programmed Death 1 ◽  
Gross Lesions

Marek’s disease (MD) is an infectious malignant T-cell lymphoma proliferative disease caused by Marek’s disease virus (MDV). In recent years, the emergence of very virulent (vv) and/or very virulent plus (vv +) strains of MDV in the field has been suggested as one of the causes of vaccination failure. The pathogenicity of the MDV strain GX18NNM4, isolated from a clinical outbreak in a broiler breeder flock that was vaccinated with CVI988/Rispens, was investigated. In the vaccination-challenge test, GX18NNM4 was able to break through the protections provided by the vaccines CVI988 and 814. It also significantly reduced body weight gain and caused marked gross lesions and a large area of infiltration of neoplastic lymphocyte cells in the heart, liver, pancreas, etc. of the infected birds. In addition, the expressions of programmed death 1 (PD-1) and its ligand, programmed death ligand 1 (PD-L1), in the spleens and cecal tonsils (CTs) of the unvaccinated challenged birds were significantly increased compared to those in the vaccinated challenged birds, indicating that the PD-1/PD-L1 pathway is related to immune evasion mechanisms. The results showed that the GX18NNM4 strain could cause severe immunosuppression and significantly decrease the protections provided by the current commercial vaccines, thus showing GX18NNM4 to be a vv + MDV strain.

scholarly journals The New Porcine Epidemic Diarrhea Virus Outbreak May Mean That Existing Commercial Vaccines Are Not Enough to Fully Protect Against the Epidemic Strains

2021 ◽  
Vol 8 ◽  
Author(s):  
Qi Gao ◽  
Zezhong Zheng ◽  
Heng Wang ◽  
Songqiang Yi ◽  
Guihong Zhang ◽  
...  
Keyword(s):  
Porcine Epidemic Diarrhea Virus ◽  
Prevention And Control ◽  
Clinical Symptoms ◽  
Control Measures ◽  
Watery Diarrhea ◽  
Sequencing Analysis ◽  
Diarrhea Virus ◽  
Pig Farm ◽  
Porcine Epidemic Diarrhea ◽  
And Control

Background: On October 30, 2020, piglets and sows in the farrowing house of a pig farm in Jiangxi showed clinical symptoms such as anorexia, watery diarrhea, and vomiting. Epidemiological test, clinical necropsy, and RT-PCR test were carried out on the pig farm for diagnosis. After comprehensive considerations, the disease was judged as porcine epidemic diarrhea virus infection.Results: Thereafter, a series of comprehensive prevention and control measures such as emergency vaccination with autogenous vaccines were adopted. Half a month after inoculation with autogenous vaccines for the farm, the mortality rate of newborn piglets in the farrowing house began to decline, and production gradually returned to being stable. The second-generation sequencing analysis and phylogenetic analysis showed that the porcine epidemic diarrhea virus (PEDV) sequence obtained from the stool and small intestine samples of the diseased pigs on the farm was 97.8% homologous to the vaccine strain. At the same time, antibody testing found that the vaccinated pigs on the pig farm had satisfactory immune response.Conclusion: This case indicated that the PEDV outbreak on the pig farm might aggravate owing to the strain being mutated and could escape the immune protection of the existing vaccine. This case has accumulated technical data for the clinical prevention and control of porcine epidemic diarrhea.

ESTIMATION OF SARS COV 2 SPECIFIC ANTIBODIES SEROPREVALENCE IN HEALTHCARE WORKERS IN DISTRICT UDAIPUR, INDIA

2021 ◽  
pp. 31-33
Author(s):  
Shelesh Kumar Swami ◽  
Nitesh Kumar Chauhan ◽  
Shuchi Goyal ◽  
A.K. Verma ◽  
Shweta Biyani
Keyword(s):  
Healthcare Workers ◽  
Clinical Symptoms ◽  
Control Measures ◽  
High Risk Population ◽  
Rt Pcr ◽  
Know How ◽  
Novel Coronavirus ◽  
And Control ◽  
Infection Eradication ◽  
Cumulative Prevalence

Background: Current pandemic caused by Novel coronavirus (COVID-19) causes clinical symptoms from fever to acute respiratory distress syndrome but may remain mild or asymptomatic. To evaluate the cumulative prevalence of SARS-CoV-2 infection in a community and know how immune response develops in the population, reliable assay alongwith RT-PCR for detection of SARS CoV 2 antibodies is needed. Healthcare workers (HCWs) represent a high-risk population for infection with SARS-CoV-2. Methods: We evaluated total antibodies recognizing the SARS CoV 2 receptor binding domain (S1-RBD) or the Spike protein over a period of six months in a total of 310 healthcare workers engaged in hospital using SARS-CoV-2 Total antibody assay kit. The overall Findings: seroprevalence found in our analysis was 41.93%. In case of males the percentage positive was found to be signicantly higher at 43.91%, compared to females at 36.25%. Seroprevalence was signicantly higher in 50 years above age group in comparison to 20-50 years old aged healthcare workers. The seroprevalence was higher in doctors, nursing staff and lab technicians than other healthcare professionals as 44.6%. Conclusions: This study showed high seroprevalence of SARS-CoV-2 in healthcare workers which means remaining proportion of the healthcare workers are still susceptible to the infection. Good compliance to infection eradication and control measures, adequate PPEs, and early detection and isolation of healthcare workers infected with SARS-CoV-2 are mandatory to reduce the risk of SARS-CoV-2 infection

Marek’s disease virus: lytic replication, oncogenesis and control

2006 ◽  
Vol 5 (6) ◽  
pp. 761-772 ◽  
Author(s):  
Keith W Jarosinski ◽  
B Karsten Tischer ◽  
Sascha Trapp ◽  
Nikolaus Osterrieder
Keyword(s):  
Disease Virus ◽  
Marek's Disease Virus ◽  
Lytic Replication ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
And Control

scholarly journals IFNα and IFNγ Impede Marek’s Disease Progression

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1103 ◽  
Author(s):  
Luca D. Bertzbach ◽  
Olof Harlin ◽  
Sonja Härtle ◽  
Frank Fehler ◽  
Tereza Vychodil ◽  
...  
Keyword(s):  
Immune Responses ◽  
Disease Onset ◽  
Antiviral Effect ◽  
Lymphoproliferative Disease ◽  
Innate Immune ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Innate Immune Responses

Marek’s disease virus (MDV) is an alphaherpesvirus that causes Marek’s disease, a malignant lymphoproliferative disease of domestic chickens. While MDV vaccines protect animals from clinical disease, they do not provide sterilizing immunity and allow field strains to circulate and evolve in vaccinated flocks. Therefore, there is a need for improved vaccines and for a better understanding of innate and adaptive immune responses against MDV infections. Interferons (IFNs) play important roles in the innate immune defenses against viruses and induce upregulation of a cellular antiviral state. In this report, we quantified the potent antiviral effect of IFNα and IFNγ against MDV infections in vitro. Moreover, we demonstrate that both cytokines can delay Marek’s disease onset and progression in vivo. Additionally, blocking of endogenous IFNα using a specific monoclonal antibody, in turn, accelerated disease. In summary, our data reveal the effects of IFNα and IFNγ on MDV infection and improve our understanding of innate immune responses against this oncogenic virus.

scholarly journals Isolation of Marek's disease virus from Japanese quail with lymphoproliferative disease

1990 ◽  
Vol 19 (1) ◽  
pp. 119-129 ◽  
Author(s):  
K. Imai ◽  
N. Yuasa ◽  
S. Kobayashp ◽  
K. Nakamura ◽  
K. Tsukamoto ◽  
...  
Keyword(s):  
Disease Virus ◽  
Japanese Quail ◽  
Lymphoproliferative Disease ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease

scholarly journals The first community outbreak of COVID-19 in Viet Nam: description and lessons learned

2021 ◽  
Vol 12 (2) ◽  
pp. 42-50
Author(s):  
Duong Nhu Tran ◽  
Quynh Mai Thi Le ◽  
Hien Tran Nguyen ◽  
Nghia Duy Ngu ◽  
Khoa Trong Nguyen ◽  
...  
Keyword(s):  
Preventive Measures ◽  
Clinical Symptoms ◽  
Lessons Learned ◽  
Control Measures ◽  
Contact Tracing ◽  
Viet Nam ◽  
Prevention And Control Measures ◽  
Novel Coronavirus ◽  
Nonpharmaceutical Interventions ◽  
And Control

Objective: At the time of this study, the prevention of novel coronavirus disease 2019 (COVID-19) relied solely on nonpharmaceutical interventions. Implementation of these interventions is not always optimal and, consequently, several cases were imported into non-epidemic areas and led to large community outbreaks. This report describes the characteristics of the first community outbreak of COVID-19 in Viet Nam and the intensive preventive measures taken in response. Methods: Cases were detected and tested for SARS-CoV-2 by real-time reverse transcriptase polymerase chain reaction. Contact tracing and active surveillance were conducted to identify suspected cases and individuals at risk. Clinical symptoms were recorded using a standardized questionnaire. Results: In Vinh Phuc province from 20 January to 3 March 2020, there were 11 confirmed cases among 158 suspected cases and 663 contacts. Nine of the confirmed cases (81.8%) had mild symptoms at the time of detection and two (18.2%) were asymptomatic; none required admission to an intensive care unit. Five prevention and control measures were implemented, including quarantining a community of 10 645 individuals for 20 days. The outbreak was successfully contained as of 13 February 2020. Discussion: In the absence of specific interventions, the intensive use of combined preventive measures can mitigate the spread of COVID-19. The lessons learned may be useful for other communities.

Sign in / Sign up

Export Citation Format

Share Document