Molecular characterisation of infectious bursal disease virus in Namibia, 2017

Molini, Umberto; Aikukutu, Gottlieb; Kabajani, Juliet; Khaiseb, Siegfried; Cattoli, Giovanni; Dundon, William G.

doi:10.4102/ojvr.v86i1.1676

Cited by 4 publications

(1 citation statement)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…IBDV RNA was detected on five of these farms [Farm 35 in Oyo (nvIBDV) and Farms 1 (vvIBDV), 8, 16, and 24 in Kano], suggesting there was circulating IBD virus on the study farms at the time of the sampling. This was supported by sequencing results, where sequences from Farm 1 were most closely related to a clade of vvIBDV previously reported in Africa ( 37 ). Additionally, the VP2 sequence from this farm was closely related to reported strains belonging to a unique cluster of northwest Nigerian field IBDV strains isolated from Kaduna and Katsina states, both of which neighbor Kano state region ( 38 – 40 ).…”

Section: Discussionsupporting

confidence: 85%

Evaluating Disease Threats to Sustainable Poultry Production in Africa: Newcastle Disease, Infectious Bursal Disease, and Avian Infectious Bronchitis in Commercial Poultry Flocks in Kano and Oyo States, Nigeria

et al. 2021

View full text Add to dashboard Cite

The growth of the poultry industry in Nigeria is constrained by major poultry diseases, despite the implementation of vaccination programs. This study aimed to assess the level of protection against Newcastle disease (ND), infectious bursal disease (IBD), and avian infectious bronchitis (IB) afforded by current vaccination schedules and characterize the circulating virus strains in commercial poultry flocks in Nigeria. A cross-sectional study was conducted on 44 commercial poultry farms in Oyo and Kano states of Nigeria. Serum and tissue samples and data on flock, clinical and vaccination records were collected on each farm. Farms were classified as being protected or not protected against ND, IBD and IB based on a defined criterion. Real-time reverse transcription polymerase chain reaction (rRT-PCR) testing was performed for each target virus on tissue samples and positive samples were sequenced. A total of 15/44 (34.1%), 35/44 (79.5%), and 1/44 (2.3%) farms were considered to be protected against ND, IBD, and IB, respectively, at the time of sampling. NDV RNA was detected on 7/44 (15.9%) farms and sequences obtained from 3/7 farms were characterized as the lentogenic strain. Infectious bursal disease virus (IBDV) RNA was detected on 16/44 (36.4%) farms tested; very virulent (vv) IBDV and non-virulent (nv) IBDV strains were both detected in 3/16 (18.8%) positive samples. Sequences of IBDV isolates were either clustered with a group of genotype 3 virulent IBDV strains or were related to vaccine strains MB and D78 strains. IBV RNA was detected on 36/44 (81.8%) farms, with variant02, Massachusetts, 4/91, and Q1 variants detected. Sequences of IBV isolates were either clustered with the vaccines strains Massachusetts M41 and H120 or were most closely related to the D274-like strains or a clade of sequences reported in Nigeria and Niger in 2006 and 2007. This study revealed that most study farms in Oyo and Kano states did not have adequate protective antibody titers against IBV and NDV and were therefore at risk of field challenge. Infectious bursal disease virus and IBV RNA were detected on farms with a history of vaccination suggesting potential vaccination failure, or that the vaccine strains used mismatch with the circulating strains and are therefore not protective.

show abstract

Section: Discussionsupporting

confidence: 85%