AbstractMarek’s disease (MD) is a devastating neoplastic disease of poultry caused by MD virus (MDV). MD is one of the several diseases limiting the thriving Nigerian poultry industry. MD is mostly diagnosed in Nigeria based on history and gross lesions without laboratory investigations leading to underreporting of the disease. This study investigated MD outbreaks in poultry farms using polymerase chain reaction (PCR) and histopathology. Tumourous visceral organs were collected from dead chickens presented to veterinary clinics from 110 farms in Plateau State, North Central Nigeria from April 2013 to August 2014. Clinical signs observed in affected chickens were paralysis, stunting and uneven growth. Whilst the gross lesions observed were hepatomegaly, splenomegaly with lymphoma, prominent peripheral nerves and cachexia. The meq gene of MDV‑1 was detected by PCR in 55.0% (n = 11/20) of broilers and 71.1% (n = 64/90) of vaccinated layer chicken samples collected. Microscopy revealed severe diffuse lymphocytic infiltrations in the heart, spleen and liver of chickens with tumourous gross lesions. Based on history, gross lesions, detection of meq gene of MDV‑1 by PCR and histopathology results, MD was confirmed in the affected farms. Despite vaccination, outbreaks of MD still occurs in poultry farms in Nigeria. This study represents the first confirmatory diagnosis of MD in vaccinated poultry in Nigeria.
Adedeji A.J., Akanbi O.B., Luka P.D. & Abdu P. 2019. Natural outbreak of Marek's disease in indigenous chicken and Japanese quail (Coturnix coturnix japonica) in Jos, Plateau State, Nigeria. Open Vet J, 9(2),151–156.
Adedeji A.J., Abdu P.A., Luka P.D., Owoade A.A. & Joannis T.M. 2017. Application of loop-mediated isothermal amplification assay in the detection of herpesvirus of turkey (FC 126 strain) from chicken samples in Nigeria. Vet World, 10 (11), 1383–1388.
Akanbi O B., Shittu I., Barde I.J., & Rimfa A. G. 2020. Molecular and Pathological investigation of a natural outbreak of Newcastle Disease caused by genotype XVII in white leghorn chickens. Avian Path, 49(4), 394-403.
Akinwumi J., Okike I. & Karl M.R. 2010. Analyses of the poultry value chain and its linkages and interactions with HPAI risk factors in Nigeria. Pro-poor HPAI Risk Reduction, Africa/Indonesia Team Working Paper n. 34. London, DFID Collaborative Research. www.hpai-research.net.
Atkins K.E., Read A.F. Walkden-Brown S.W. Savill N.J. & Woolhouse M.E. 2013. The effectiveness of mass vaccination on Marek's disease virus (MDV) outbreaks and detection within a broiler barn: a modeling study. Epidemics, 5(4), 208–217.
Bertzbach L.D., Conradie A. M., You Y. & Kaufer B.B. 2020. Latest Insights into Marek's Disease Virus Pathogenesis and Tumorigenesis. Cancers, 12(3), 647.
Biggs P. M. & Nair V. 2012. The long view: 40 years of Marek’s disease research and Avian Pathology. Avian Path, 41(1), 3-9.
Boodhoo N., Gurung A., Sharif S. & Behboudi S. 2016. Marek's disease in chickens: a review with focus on immunology. Vet Res, 47(1), 119.
Davidson I. & Borenshtain R. 2002. The feather tips of commercial chickens are a favorable source of DNA for the amplification of Marek’s disease virus and avian leukosis virus, subgroup J. Avian Pathol, 31(3), 237-240.
Denesvre C. 2013. Marek’s disease virus morphogenesis. Avian Dis, 57, 340-350.
Diaz F.J.T. 2014. Marek’s disease. In Vaccination of poultry (Diaz F.J.T., Martinez C.G., van den Berg T., Pena S.T. & Hauck R. Eds.) Zaragoza, Spain, Groupo Asis Biomedia, 3–8.
Dunn J. & Gimeno I.M. 2013. Current status of Marek’s disease in the United States and worldwide based on a questionnaire survey. Avian Dis, 57(2 Suppl), 483-490.
Ekong P. S., Cardona C. J., Bryssinck W., Ikechukwu-Eneh C., Lombin L. H. & Carpenter T.E. 2018. Spatial clustering of pathology submissions during the initial introduction and spread of avian influenza H5N1 in poultry in Nigeria in 2006-2007. Vet Ital, 54(1), 13 -20.
Gimeno I. M. & Schat K.A. 2018. Virus-Induced Immunosuppression in Chickens. Avian Dis, 62(3), 272–285.
Gimeno I. M.& Pandiri A.R.2013. Virus-induced immunosuppression: Marek’s disease virus infection and associated syndromes. In: Immunosuppresive diseases of poultry (Gimeno I. M., ed.). Servet-Group Asis, Zaragoza, 124–152.
Gimeno I.M. 2004. Future strategies for controlling Marek's disease. In Marek’s Disease An Evolving Problem. The Netherland, Elsevier, 186-199.
Gimeno I.M. 2008. Marek’s disease vaccines: A solution for today but a worry for tomorrow? Vaccine, 26 (Suppl 3), C31–C41.
Haq K., Schat K.A. & Sharif S. 2013. Immunity to Marek's disease: where are we now? Dev Comp Immunol, 41(3), 439–446.
Hill D.H. & Davis O.S. 1962. Disease incidence , age and seasonal trends in poultry flock losses at University College, Ibadan, Nigeria, West Africa. J Biol Chem, 5, 5-58.
Islam T., Walkden-Brown S. W., Renz K. G., Islam, A. F. & Ralapanawe, S. 2014. Replication kinetics and shedding of very virulent Marek's disease virus and vaccinal Rispens/CVI988 virus during single and mixed infections varying in order and interval between infections. Vet Microb, 173(3-4), 208–223.
Islam T., Walkden-Brown S.W., Renz K.G., Fakhrul Islam A.F M. & Ralapanawe S. 2013.Vaccination-challenge interval markedly influences protection provided by Rispens CVI988 vaccine against very virulent Marek’s disease virus challenge. Avian Path, 42(6), 516-526.
Jwander L.O., Abdu P.A., Ibrahim N.D.G. & Nok J.A. 2015. Farmers' Awareness of Marek's Disease and Biosecurity Practices in Poultry Production in Selected States of Nigeria. Nig Vet J, 35 (1), 928-936.
Lian X., Ming X., Xu J., Cheng W., Zhang X., Chen H., Ding C., Jung Y. S. & Qian Y. 2018. First molecular detection and characterization of Marek's disease virus in red- crowned cranes (Grus japonensis): a case report. BMC Vet Res, 14(1), 122.
Maduka C.V., Igbokwe I. O. & Atsanda N.N. 2016. Appraisal of Chicken Production with Associated Biosecurity Practices in Commercial Poultry Farms Located in Jos, Nigeria. Scientifica, 1914692.
McPherson, M. C., & Delany, M. E. 2016. Virus and host genomic, molecular, and cellular interactions during Marek's disease pathogenesis and oncogenesis. Poult Sci, 95(2), 412–429.
Morrow C.& Fehler F. 2004. Marek's disease: a worldwide problem. Marek’s disease An Evolving Problem. The Netherland, Elsevier, 49-61.
Murata S., Hayashi Y., Kato A., Isezaki M., Takasaki S., Onuma M., Osa Y., Konnai A.M. S. & Ohashi K. 2012. Surveillance of Marek’s disease virus in migratory and sedentary birds in Hokkaido, Japan. Vet J, 192, 538–540.
Nair N. 2005. Evolution of Marek's disease -- a paradigm for incessant race between the pathogen and the host. Vet J, 170, 175–183.
Nair V. 2018. Spotlight on avian pathology: Marek's disease. Avian Pathol, 47(5), 440–442.
Okwor E.C. & Eze D.C. 2011. Outbreak and persistence of Mareks disease in batches of birds reared in a rural poultry farm located at Nsukka, South east Nigeria. Int J Poult Sci, 10(8), 617-620.
Owoade A.A. & Oni O.O. 2008. Molecular detection of Marek’s disease virus in some poultry flocks in southwestern Nigeria by polymerase chain reaction. Nig Poul Sci J, 5(3), 113-118.
Payne L. N. 2004. Pathological responses to infection. In Marek’s disease An Evolving Problem. The Netherland, Elsevier, 78-97.
Payne L.N. 1985. Marek's Disease-Scientific Basis and Methods Of Control. Martinus Nijhoff Publishing, Boston, 1-11.
Ralapanawe S., Renz K. G., Burgess S. K. & Walkden-Brown S. W. 2016b. Field studies of the detection, persistence and spread of the Rispens CVI988 vaccine virus and the extent of co-infection with Marek's disease virus. Aus Vet J, 94(9), 329–337.
Ralapanawe S., Walkden-Brown S. W., Renz K. G. & Islam A. F. 2016a. Protection provided by Rispens CVI988 vaccine against Marek's disease virus isolates of different pathotypes and early prediction of vaccine take and MD outcome. Avian Path, 45(1), 26–37.
Reddy S. M., Izumiya Y. & Lupiani B. 2017. Marek's disease vaccines: Current status, and strategies for improvement and development of vector vaccines. Vet Microbiol, 206, 113–120.
Renz K. G., Cheetham B. F. & Walkden-Brown S. W. 2013. Differentiation between pathogenic serotype 1 isolates of Marek's disease virus and the Rispens CVI988 vaccine in Australia using real-time PCR and high resolution melt curve analysis. J Virol Methods, 187(1), 144–152.
Rozins C., Day T. & Greenhalgh S. 2019. Managing Marek's disease in the egg industry. Epidemics, 27, 52–58.
Sani N.A., Aliyu H.B., Musa I.W., Wakawa A.M., Abalaka S.E., Oladele S.B., Sa’idu L. & Abdu P.A. 2017. A nine-year retrospective study of avian neoplastic diseases in Zaria, Kaduna state, Nigeria. S J Vet Sci, 15(1), 36–41.
Schat K. A. & Nair V. 2013. Neoplastic diseases: Marek’s disease. In Diseases of Poultry, 13th ed. Ames, Iowa, USA, Wiley‐Blackwell, 515–552.
Schat K. A. 2016. History of the First-Generation Marek's Disease Vaccines: The Science and Little-Known Facts. Avian Dis, 60(4), 715–724.
Shittu I., Adedeji A. J., Luka P. D., Asala O. O., Sati N. M., Nwagbo I.O., Chinyere C. N., Arowolo O. O., Adole, J. A., Emennaa P., Abdu P.A. & Joannis T. M. 2019. Avian leukosis virus subgroup - J as a contaminant in live commercially available poultry vaccines distributed in Nigeria. Biologicals, 57, 29–33.
Woz´niakowski G., Samorek-Salamonowicz E. & Kozdrun W. 2013. Comparison of loop-mediated isothermal amplification and PCR for the detection and differentiation of Marek’s disease virus serotype 1, 2 and 3. Avian Dis, 57, 1–5.
Wu C., Gan J., Jin Q., Chen C., Liang P., Wu Y., Liu X., Ma L., & Davison F. 2009. Revaccination with Marek's disease vaccines induces productive infection and superior immunity. Clin Vaccine Immunol, 16(2), 184–193.
Zelnik V. 2004. Diagnosis of Marek's disease. In Marek’s Disease An Evolving Problem.The Netherlans, Elsevier, 156-167.
Zhang Y. P., Li Z. J., Bao K. Y., Lv H. C., Gao Y. L., Gao H. L., Qi X. L., Cui H. Y., Wang Y. Q., Ren X. G., Wang X. M. & Liu C. J. 2015. Pathogenic characteristics of Marek's disease virus field strains prevalent in China and the effectiveness of existing vaccines against them. Vet Microbiol, 177(1-2), 62–68.