Genotype Diversity of Newcastle Disease Virus in Nigeria: Disease Control Challenges and Future Outlook (original) (raw)
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Virus Genes, 2020
The causative agent of Newcastle disease (ND) of poultry is the avian paramyxovirus-1, also commonly known as ND virus (NDV). Like in many developing countries, ND is endemic in Niger and has significant economic impact on commercial and backyard poultry production. NDVs were characterized in Niger between 2006 and 2008 and shown to belong to genotypes XIV.1 and XVII. In order to determine the current situation regarding the virus in Niger, tracheas (n = 384) were collected for the detection of NDV from both healthy (n = 335) and sick (n = 49) backyard poultry in 2019. Of these samples, 24 from sick chickens were positive for NDV by conventional RT-PCR. Sequencing of the fusion protein gene and phylogenetic analysis revealed that the viruses belonged to either genotype XIV.2 or XVIII.2. No NDVs of genotype XIV.1 or XVII were identified in the current study highlighting the dynamic nature of NDV circulation in Niger and the region.
Background: Newcastle disease is still a serious disease of poultry especially in backyard free-range production systems despite the availability of cross protective vaccines. Healthy-looking poultry from live bird markets have been suspected as a major source of disease spread although limited studies have been conducted to ascertain the presence of the virulent strains in the markets and to understand how they are related to outbreak strains. Methods: This study evaluated the occurrence of Newcastle disease virus in samples collected from poultry in live bird markets across Uganda. The isolates were pathoyped using standard methods (mean death time (MDT), intracelebral pathogenicity index (ICPI), and sequencing of the fusion protein cleavage site motif) and also phylogenetically analysed after sequencing of the full fusion and hemagglutin-neuraminidase genes. The isolates were classified into genotypes and subgenotypes based on the full fusion protein gene classification system and compared with other strains in the region and world-wide. Results: Virulent avian paramyxovirus type I (APMV-1) (Newcastle disease virus) was isolated in healthy-looking poultry in live bird markets. The viruses belonged to a new subgenotype, Vd, in genotype V, and clustered together with Tanzania and Kenya strains. They harbored low genetic diversity. Conclusion: The occurrence of virulent AMPV-1 strains in live bird markets may serve as sources of Newcastle disease outbreaks in non-commercial farms. Keywords: Newcastle disease virus, Live bird markets, Genetic diversity, Pathogenicity, Uganda
Journal of Clinical Microbiology, 2013
Despite rampant Newcastle disease virus (NDV) outbreaks in Africa for decades, the information about the genetic characteristics of the virulent strains circulating in West and Central Africa is still scarce. In this study, 96 complete NDV fusion gene sequences were obtained from poultry sampled in Cameroon, Central African Republic, Côte d'Ivoire, and Nigeria between 2006 and 2011. Based on rational criteria recently proposed for the classification of NDV strains into classes, genotypes, and subgenotypes, we revisited the classification of virulent strains, in particular those from West and Central Africa, leading to their grouping into genotype XIV and newly defined genotypes XVII and XVIII, each with two subgenotypes. Phylogenetic analyses revealed that several (sub)genotypes are found in almost every country. In Cameroon, most strains were related to vaccine strains, but a single genotype XVII strain was also found. Only three highly similar genotype XVII strains were detected in Central African Republic. Subgenotypes XVIIa, XVIIIa, and XVIIIb cocirculated in Côte d'Ivoire, while subgenotypes XIVa, XIVb, XVIIa, XVIIb, and XVIIIb were found in Nigeria. While these genotypes are so far geographically restricted, local and international trade of domestic and exotic birds may lead to their spread beyond West and Central Africa. A high genetic diversity, mutations in important neutralizing epitopes paired with suboptimal vaccination, various levels of clinical responses of poultry and wild birds to virulent strains, strains with new cleavage sites, and other genetic modifications found in these genotypes tend to undermine and complicate NDV management in Africa.
Viruses, 2021
Kenyan poultry consists of ~80% free-range indigenous chickens kept in small flocks (~30 birds) on backyard poultry farms (BPFs) and they are traded via live bird markets (LBMs). Newcastle disease virus (NDV) was detected in samples collected from chickens, wild farm birds, and other domestic poultry species during a 2017–2018 survey conducted at 66 BPFs and 21 LBMs in nine Kenyan counties. NDV nucleic acids were detected by rRT-PCR L-test in 39.5% (641/1621) of 1621 analyzed samples, of which 9.67% (62/641) were NDV-positive by both the L-test and a fusion-test designed to identify the virulent virus, with a majority being at LBMs (64.5%; 40/62) compared to BPFs (25.5%; 22/62). Virus isolation and next-generation sequencing (NGS) on a subset of samples resulted in 32 complete NDV genome sequences with 95.8–100% nucleotide identities amongst themselves and 95.7-98.2% identity with other east African isolates from 2010-2016. These isolates were classified as a new sub-genotype, V.3, and shared 86.5–88.9% and 88.5–91.8% nucleotide identities with subgenotypes V.1 and V.2 viruses, respectively. The putative fusion protein cleavage site (113R-Q-K-R↓F 117) in all 32 isolates, and a 1.86 ICPI score of an isolate from a BPF chicken that had clinical signs consistent with Newcastle disease, confirmed the high virulence of the NDVs. Compared to genotypes V and VI viruses, the attachment (HN) protein of 18 of the 32 vNDVs had amino acid substitutions in the antigenic sites. A time-scaled phylogeographic analysis suggests a west-to-east dispersal of the NDVs via the live chicken trade, but the virus origins remain unconfirmed due to scarcity of continuous and systematic surveillance data. This study reveals the widespread prevalence of vNDVs in Kenyan backyard poultry, the central role of LBMs in the dispersal and possibly generation of new virus variants, and the need for robust molecular epidemiological surveillance in poultry and non-poultry avian species.
World Journal of Advanced Research and Reviews, 2019
A study of Newcastle disease virus (NDVs) using molecular characterization in indigenous chickens in Plateau State was carried out. The birds were obtained from three geographical locations in Plateau State. Three ribonucleic acids (RNAs) of Newcastle disease viruses (NDVs) obtained from normal indigenous chickens, which were never vaccinated against Newcastle disease (ND) were characterized. These RNAs were named Lc 3, Lc 4 and Lc5, respectively. These three samples were genotypically analyzed using reverse transcription polymerase chain reaction (RT-PCR) with primers specific to the viral fusion (F) protein gene. The deduced amino acid sequences at the F0 of these three RNA between positions 112 and 117 were all the same. The three NDV RNA had phenylalanine (F) residue at position 117, confirming their high virulence to indigenous chicken in Plateau State, Nigeria. The existence of virulent NDVs in circulation in indigenous chicken could be a serious threat to commercial chicken. ...
International Journal of Microbiology, 2018
Newcastle disease (ND) is a serious disease of poultry that causes significant economic losses. Despite rampant ND outbreaks that occur annually in Kenya, the information about the NDV circulating in Kenya is still scarce. We report the first countrywide study of NDV in Kenya. Our study is aimed at evaluating the genetic characteristics of Newcastle disease viruses obtained from backyard poultry in farms and live bird markets in different regions of Kenya. We sequenced and analyzed fusion (F) protein gene, including the cleavage site, of the obtained viruses. We aligned and compared study sequences with representative NDV of different genotypes from GenBank. e fusion protein cleavage site of all the study sequences had the motif 112RRQKRFV118 indicating their velogenic nature. Phylogenetic analysis revealed that the NDV from various sites in Kenya was highly similar genetically and that it clustered together with NDV of genotype V. e study samples were 96% similar to previous Ugandan and Kenyan viruses grouped in subgenotype Vd is study points to possible circulation of NDV of similar genetic characteristics between backyard poultry farms and live bird markets in Kenya. e study also suggests the possible spread of velogenic NDV between Kenya and Uganda possibly through cross-border live bird trade. Our study provides baseline information on the genetic characteristics of NDV circulating in the Kenyan poultry population. is highlights the need for the ND control programmes to place more stringent measures on cross-border trade of live bird markets and poultry products to prevent the introduction of new strains of NDV that would otherwise be more difficult to control.
Virus Genes, 2012
Newcastle disease (ND), caused by Avian Paramyxovirus Type 1, is a highly contagious and devastating viral disease of poultry of worldwide distribution with an enormous economic impact. Although ND is reported to be endemic in Nigeria, little information exists on the molecular epidemiology and the lineage distribution of the Newcastle disease viruses (NDVs) in the country, especially in the live bird markets (LBMs). Recent studies reported the identification of three unique sub-lineages. namely; 5f, 5g and 5h in West Africa, and sub-lineages 5f and 5g in particular in non-commercial farms in Nigeria. In this study, 33 NDV isolates, which included NDVs recovered from LBMs in Nigeria, during active surveillance from 2007 to 2008 and viruses recovered from outbreaks in backyard and commercial chicken farms within the same period were analysed. Based on determination of the F 0 cleavage site amino acid sequence and phylogenetic analysis, the isolates were classified as virulent; 16 strains were identified as sub-lineage 5g and 17 as sub-lineage 5f. Interestingly, 13 strains from the 5f group formed a distinct cluster that was not identified by other groups in similar studies. The close genetic similarities identified, provided evidence for the first time of the epidemiological link between the viruses circulating in the LBMs and those recovered from outbreaks in backyard and commercial chicken farms in Nigeria between 2007 and 2008. The emergence and identification of new sub-lineages provide an insight into the high rate of genetic drift occurring in NDV strains in Nigeria, and raises a lot of concerns about the efficacy of current ND control measures in the country.
Veterinary Pathology, 2010
Newcastle disease is a severe threat to the poultry industry and is caused by Newcastle disease virus, a member of the genus Avulavirus, family Paramyxoviridae. The virus is rapidly evolving, and several new genotypes have been discovered in the past few years. Characterization of these strains is important to evaluate field changes, anticipate new outbreaks, and develop adequate control measures. Three Newcastle disease isolates (APMV-1/duck/Vietnam, Long Bien/78/2002, APMV-1/chicken/Australia/9809-19-1107/1998, and APMV-1/double-crested cormorant/USA, Nevada/19529-04/2005) from recent outbreaks were investigated via clinicopathological assessment, immunohistochemistry (IHC), in situ hybridization, virus isolation, and serology in experimentally infected 4-week-old chickens. Phylogenetic studies showed that Australia isolate belongs to class II genotype I, Long Bien to class II genotype VIId, and Nevada cormorant to class II genotype V. Even though all 3 viruses had a virulent fusi...