Occurrence of Newcastle Disease Genotype II and VII.2 strains in Vaccinated and Unvaccinated Commercial and Backyard Poultry Flocks in Lusaka Province, Zambia.

Keywords: Newcastle disease virus; NDV; poultry pathology; molecular characterisation; genotype VII.2; vaccination; Zambia

Abstract

Newcastle disease (ND) remains one of the most devastating infectious diseases of poultry worldwide, causing substantial economic losses despite the widespread use of vaccination programs. In Zambia, recurrent outbreaks continue to be reported. This study aimed to characterise the pathological features and molecular diversity of Newcastle disease virus (NDV) circulating in poultry outbreaks in Lusaka Province, Zambia. A prospective and retrospective investigation of suspected ND outbreaks reported between 2020 and 2023 was conducted. A total of 89 poultry outbreaks involving indigenous chickens, broilers, layers, and pullets were investigated. Gross pathology and histopathological examinations were performed on affected birds, followed by molecular detection of NDV using reverse transcription polymerase chain reaction (RT-PCR). Partial fusion (F) gene sequencing and phylogenetic analysis were used to determine circulating genotypes. Gross lesions were consistent with ND but lacked specificity, while histopathology revealed predominantly necro-haemorrhagic lesions affecting lymphoid tissues, gastrointestinal tract, and respiratory organs, with variable severity across production systems. Newcastle disease virus was detected in both vaccinated and unvaccinated flocks, with no statistically significant difference in detection rates between the two groups (p > 0.05). Molecular analysis identified the circulation of virulent NDV genotype VII.2, alongside genotype II strains closely related to vaccine lineages. The detection of virulent NDV genotypes in vaccinated flocks highlights persistent gaps in Newcastle disease control in Zambia. These findings underscore the need for strengthened molecular surveillance, improved vaccination strategies, and enhanced biosecurity to reduce the burden of ND in poultry production systems.

References

1. Abdisa T, Tagesu T. Review on Newcastle Disease of Poultry and its Public Health Importance. J Vet Sci Technol. 2017;08(03).
2. Aliye S, Endale H, Mathewos M, Fesseha H. Study on Seroprevalence and Associated Risk Factors of Newcastle Disease in Smallholder Poultry Farms in Sodo Zuria District, Wolaita Zone, Southern Ethiopia. Al-Shammari AM, editor. Adv Virol. 2022 Sep 21 ;2022:1–8.
3. Getabalew M, Alemneh T, Akeberegn D, Getahun D, Zewdie D. Epidemiology, Diagnosis & Prevention of Newcastle Disease in Poultry. Am J Biomed Sci Res. 2019 May 16;3(1):50–9.
4. Amoia CF, Hakizimana JN, Chengula AA, Munir M, Misinzo G, Weger-Lucarelli J. Genomic Diversity and Geographic Distribution of Newcastle Disease Virus Genotypes in Africa: Implications for Diagnosis, Vaccination, and Regional Collaboration. Viruses. 2024 May 1;16(5).
5. Mariana S e S, Susta L, Moresco K, Swayne DE. Vaccination of chickens decreased Newcastle disease virus contamination in eggs. Avian Pathol [Internet]. 2016 Jan 2 [cited 2025 Jun 11];45(1):38–45.
6. Getabalew M, Alemneh T, Akeberegn D, Getahun D, Zewdie D. epidemiology, Diagnosis & Prevention of Newcastle disease in poultry. Am J Biomed Sci Res. 2019;16(2):50–9.
7. Hu Z, He X, Deng J, Hu J, Liu X. Current situation and future direction of Newcastle disease vaccines. Vet Res. 2022 Nov 2;53(1):99.
8. Mao Q, Ma S, Schrickel PL, Zhao P, Wang J, Zhang Y, et al. Review detection of Newcastle disease virus. Front Vet Sci . 2022 ;9:936251.
9. Kalonda A, Saasa N, Kajihara M, Nao N, Moonga L, Ndebe J, et al. Phylogenetic Analysis of Newcastle Disease Virus Isolated from Poultry in Live Bird Markets and Wild Waterfowl in Zambia. Microorganisms. 2024 Feb 8;12(2):354.
10. Hu Z, He X, Deng J, Hu J, Liu X. Current situation and future direction of Newcastle disease vaccines. Vet Res. 2022 Nov 26;53(1):99.
11. Alders RG, Inoue S, Katongo JC. Prevalence and evaluation of Hitchner B1 and V4 vaccines for the control of Newcastle disease in village chickens in Zambia. Prev Vet Med . 1994 ;21(2):125–32.
12. Mubamba C, Ramsay G, Abolnik C, Dautu G, Gummow B. A retrospective study and predictive modelling of Newcastle Disease trends among rural poultry of eastern Zambia. Prev Vet Me. 2016;133:97–107.
13. Mubamba C. An exploration of novel approaches to improve surveillance for infectious diseases in rural poultry of Zambia using Newcastle Disease as a case study[PhD Thesis]. James Cook University; 2018.
14. Ndashe K, Simulundu E, Hang’ombe BM, Moonga L, Ogawa H, Takada A, et al. Molecular characterization of infectious bursal disease viruses detected in vaccinated commercial broiler flocks in Lusaka, Zambia. Arch Virol. 2016 Mar;161(3):513–9.
15. Werling D, Behboudi S, Mayahi M, Wang C, Copyright fvets, Ma S, et al. Review detection of Newcastle disease virus.
16. Bello A, Umaru MA, Baraya YS, Adamu YA, Jibir M, Garba S, et al. Postmortem procedure and diagnostic avian pathology. 2012;1(January 2014):37–41.
17. Chong WC, Wu R, Tu Y. A Study on Tissue Processing. Int J Innov Interdiscip Res Issue. 2012;3.
18. Hussein EA, Hair-Bejo M, Adamu L, Omar AR, Arshad SS, Awad EA, et al. Scoring System for Lesions Induced by Different Strains of Newcastle Disease Virus in Chicken. Vet Med Int. 2018;2018.
19. Kalonda A, Saasa N, Kajihara M, Nao N, Moonga L, Ndebe J, et al. Phylogenetic Analysis of Newcastle Disease Virus Isolated from Poultry in Live Bird Markets and Wild Waterfowl in Zambia. Microorganisms. 2024 Feb 1;12(2).
20. Harrison SJ, Moono MB, Odubote IK. Production Systems and Management Practices of Chicken Populations in Zambia. Sustain Agric Res. 2024 Jan 4;13(1):61.
21. Kanyama CM, Ngosa M, Sibanda TZ, Moss AF, Crowley TM. Rural Poultry Farming: Leveraging Higher Poultry Input Costs to Grow Zambia’s Indigenous Chicken Sector. Poultry. 2024 Dec 1;3(4):383–98.
22. Regmi S, Bhatta R, Pal P, Shrestha A, Mató T, Puri B, et al. Clinicopathological and Molecular Investigation of Newcastle Disease Outbreaks in Vaccinated and Non-Vaccinated Broiler Chicken Flocks in Nepal. Animals. 2024 Aug 21.
23. Emeru BA, Dame ,Dejene Getachew, and Desta HT. Molecular Detection and Serological Investigation of Newcastle Disease in Intensive, Semi-Intensive, and Backyard Production Systems in Central and Southwestern Areas of Ethiopia. Vet Med Res Rep . 2024 Dec 3;15:141–8.
24. Abadula TA, Jilo SA, Hussein JA, Abadura SZ. Poultry Production Status, Major Constraints, and Future Prospective. J World’s Poult Sci. 2022 Dec 25;1(1):22–8.
25. Mubamba C. An exploration of novel approaches to improve surveillance for infectious diseases in rural poultry of Zambia using Newcastle Disease as a case study . James Cook University; 2018.
26. Shofa M, Wibawan IWT, Zarkasie K, Setiyaningsih S. Molecular Analysis of Newcastle Disease Virus Isolated from A Vaccinated Layer Farm in Indonesia. IOP Conf Ser Earth Environ Sci. 2018 Nov 2;197:012044.
27. Moharam I, Razik AA el, Sultan H, Ghezlan M, Meseko C, Franzke K, et al. Investigation of suspected Newcastle disease (ND) outbreaks in Egypt uncovers a high virus velogenic ND virus burden in small-scale holdings and the presence of multiple pathogens. Avian Pathol. 2019;48(5):406–15.
28. Amoia CFAN, Nnadi PA, Ezema C, Couacy-Hymann E. Epidemiology of Newcastle disease in Africa with emphasis on Côte d’Ivoire: A review. Vet World . 2021 Jul 3;1727–40.
29. Rufai MA, Jato AO. Assessing the prevalence of gastrointestinal tract parasites of poultry and their environmental risk factors in poultry in Iwo, Osun State Nigeria. Ife J Sci . 2017 Jul 31;19(1):7.
30. Shifaw A, Feyera T, Walkden-Brown SW, Sharpe B, Elliott T, Ruhnke I. Global and regional prevalence of helminth infection in chickens over time: a systematic review and meta-analysis. Poult Sci. 2021 May ;100(5):101082.
31. Sharma N, Hunt PW, Hine BC, Ruhnke I. The impacts of Ascaridia galli on performance, health, and immune responses of laying hens: new insights into an old problem. Poult Sci . 2019 Dec;98(12):6517–26.
32. Nisa Q un, Younus M, Rehman M ur, Maqbool A, Khan I, Umar S. Pathological Alterations during Co-Infection of Newcastle Disease Virus with Escherichia coli in Broiler Chicken. Pak J Zool . 2017 Oct ;49(6).
33. Srinivasan P, Blasurbramaniam G, Thippichettipalayam Murthy, Balachandran P. Clinical and Gross Pathological Investigations of Internal Laying in Commercial Layer Chicken. Adv Anim Vet Sci . 2015;3(1):71–8.
34. Bello MB, Yusoff K, Ideris A, Hair-Bejo M, Peeters BPH, Omar AR. Diagnostic and Vaccination Approaches for Newcastle Disease Virus in Poultry: The Current and Emerging Perspectives. BioMed Res Int. 2018;2018.
35. Dey S, Pathak D, Ramamurthy N, Maity HK, Chellappa MM.

Infectious bursal disease virus in chickens: prevalence, impact, and management strategies

. Vet Med Res Rep . 2019 Aug;Volume 10:85–97.
36. Khair H, El Ballal S, El-Shemy A, Anis A, El-Bahrawy A. Pathological and Epidemiological Study on Newcastle Disease in Broiler Chicken Farms in Egypt between 2021-2022. J Curr Vet Res. 2024 Apr 1;6(1):226–45.
37. Dzogbema KFX, Talaki E, Batawui KB, Dao BB. Review on Newcastle disease in poultry. Int J Biol Chem Sci. 2021 Jun 23;15(2):773–89.
38. Yune N, Abdela N. Update on Epidemiology, Diagnosis and Control Technique of Newcastle Disease. J Vet Sci Technol. 2017 Mar 6;8(2):1–6.
39. Etriwati, Ratih D, Handharyani E, Setiyaningsih S. Pathology and immunohistochemistry study of Newcastle disease field case in chicken in Indonesia. Vet World. 2017 Sep 13;10(9):1066–71.
40. Otiang E, Thumbi SM, Campbell ZA, Njagi LW, Nyaga PN, Palmer GH. Impact of routine Newcastle disease vaccination on chicken flock size in smallholder farms in western Kenya. PLOS ONE. 2021 Mar 18;16(3):e0248596.
Published
2026-02-26
How to Cite
1.
Mebelo N, Ndebe J, Ndashe K, Shawa M, Mweemba M, Mwenda R, Muleya W, Changula K. Occurrence of Newcastle Disease Genotype II and VII.2 strains in Vaccinated and Unvaccinated Commercial and Backyard Poultry Flocks in Lusaka Province, Zambia. Journal of Agricultural and Biomedical Sciences [Internet]. 26Feb.2026 [cited 13Apr.2026];10(2). Available from: https://journals.unza.zm/index.php/JABS/article/view/1682
Section
Veterinary Medicine