Infectious diseases are responsible for illness, deaths and economic losses in human and animals. The situation is worse in developing countries with limited resources, poor infrastructures and technology necessary for disease prevention... more
Infectious diseases are responsible for illness, deaths and economic losses in human and animals. The situation is worse in developing countries with limited resources, poor infrastructures and technology necessary for disease prevention and control. Consequently, causative agents of diseases may emerge from animal reservoirs and are transmitted from animals to human as zoonoses or sustained human-to-human transmission may occur. About 60% of infectious diseases are zoonotic and over 75% of emerging and re-emerging diseases in human are acquired from animal hosts. Globally and in Nigeria, zoonotic diseases previously controlled such as yellow fever, Orthopoxvirus (monkey pox virus), Lassa fever, anthrax etc. are re-emerging and new ones like Avian influenza, Ebola, and respiratory coronaviruses (SARS, MERS and 2019-nCoV) are emerging. In addition, the transboundary nature and inter-continental introductions of many of these pathogens threaten the national economy and public health. ...
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Phylogenetic analysis based on the complete genome coding sequence of Newcastle disease virus isolates studied here and selected closely related sequences from GenBank. Figure S3. Phylogenetic analysis based on the hypervariable region of... more
Phylogenetic analysis based on the complete genome coding sequence of Newcastle disease virus isolates studied here and selected closely related sequences from GenBank. Figure S3. Phylogenetic analysis based on the hypervariable region of the spike protein gene of Infectious bronchitis virus studied here and selected closely related sequences from GenBank. (PDF 142Â kb)
Sequences of primers used for sequencing internal gaps and missing termini. (DOCX 13Â kb)
Nucleic acid concentrations and library fragment size distributions of thirty virus isolates used in the study. (DOCX 18Â kb)
Major processing steps used in the current study (PDF 222Â kb)
Background information of the avian paramyxovirus isolates used in this study. (DOCX 15Â kb)
A 2001 strain (A/duck/Anyang/AVL-1/2001) is used as an outgroup at top. Clade V1 comprises the 5 Vietnamese isolates at the bottom of the tree, and clade V2 comprises the 9 Vietnamese isolates near the top of the tree. The European-Middle... more
A 2001 strain (A/duck/Anyang/AVL-1/2001) is used as an outgroup at top. Clade V1 comprises the 5 Vietnamese isolates at the bottom of the tree, and clade V2 comprises the 9 Vietnamese isolates near the top of the tree. The European-Middle Eastern-African (EMA) clade contains the remaining 22 isolates sequenced in this study; the 3 subclades are indicated by red, blue, and purple lines. The reassortant strain, A/chicken/Nigeria/1047–62/2006, is highlighted in red. Note that 4 segments including HA from this reassortant fall in EMA-1; the other 4 fall in EMA-2, as shown in . Bootstrap values supporting the 3 distinct EMA clades are taken from a consensus tree based on concatenated whole-genome sequences, excluding the reassortant strain. The consensus tree is provided as .<b>Copyright information:</b>Taken from "Genome Analysis Linking Recent European and African Influenza (H5N1) Viruses" 2007;13(5):713-718.Published online Jan 2007PMCID:PMC2432181.
The tree includes all HA segments isolated since 2000 from humans (82 isolates, minimum sequence length 1,000 nt), birds (503 isolates, minimum length 1500 nt), and cats (4 isolates). The 36 newly sequenced genomes are highlighted in... more
The tree includes all HA segments isolated since 2000 from humans (82 isolates, minimum sequence length 1,000 nt), birds (503 isolates, minimum length 1500 nt), and cats (4 isolates). The 36 newly sequenced genomes are highlighted in color. Human cases, which occur in all 4 of the major influenza (H5N1) clades, are highlighted in red. The scale bar indicates an F84 distance of 0.01. A full-scale version of this tree is provided as Figure 3. B) Phylogeny of 71 complete genomes (avian isolates, all 8 segments concatenated) and 3 HA sequences (human isolates, marked with red arrows) from Europe, the Middle East, Africa, Russia, and Asia. Bootstrap values represent the percentage of 1,000 bootstrap replicates for which the partition implied by the edge was observed; see Methods for further details. The 3 European-Middle Eastern-African (EMA) subclades from are indicated with the same color scheme. Isolates from human hosts are found only in EMA-1. Colors indicate locales. The names of t...
a surveillance system: live-bird market surveillance for highly pathogenic avian influenza, a case study
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Nigeria, with a population of over 190 million people, is rated among the 10 countries with the highest burden of infectious and zoonotic diseases globally. In Nigeria, there exist a sub-optimal surveillance system to monitor and track... more
Nigeria, with a population of over 190 million people, is rated among the 10 countries with the highest burden of infectious and zoonotic diseases globally. In Nigeria, there exist a sub-optimal surveillance system to monitor and track priority zoonoses. We therefore conducted a prioritization of zoonotic diseases for the first time in Nigeria to guide prevention and control efforts. Towards this, a two-day in-country consultative meeting involving experts from the human, animal, and environmental health backgrounds prioritized zoonotic diseases using a modified semi-quantitative One Health Zoonotic Disease Prioritization tool in July 2017. Overall, 36 of 52 previously selected zoonoses were identified for prioritization. Five selection criteria were used to arrive at the relative importance of prioritized diseases based on their weighted score. Overall, this zoonotic disease prioritization process marks the first major step of bringing together experts from the human-animal-environment health spectrum in Nigeria. Importantly, the country ranked rabies, avian influenza, Ebola Virus Disease, swine influenza and anthrax as the first five priority zoonoses in Nigeria. Finally, this One Health approach to prioritizing important zoonoses is a step that will help to guide future tracking and monitoring of diseases of grave public health importance in Nigeria.
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Among recurrent sanitary emergencies able to spread rapidly worldwide, avian influenza is one of the main constraints for animal health and food security. In West Africa, Nigeria has been experiencing repeated outbreaks of different... more
Among recurrent sanitary emergencies able to spread rapidly worldwide, avian influenza is one of the main constraints for animal health and food security. In West Africa, Nigeria has been experiencing repeated outbreaks of different strains of avian influenza virus (AIV) since 2006 and is also recognized as a hotspot in the region for the introduction of emerging strains by migratory wild birds. Here, we generated complete genomes of 20 highly pathogenic avian influenza (HPAI) H5N8 viruses collected during active surveillance in Nigerian live bird markets (LBM) and from outbreaks reported in the country between 2016 and 2019. Phylogenetic analysis reveals that the Nigerian viruses cluster into four separate genetic groups within HPAI H5 clade 2.3.4.4b. The first group includes 2016-2017 Nigerian viruses with high genetic similarity to H5N8 viruses detected in Central African countries, while the second includes Nigerian viruses collected both in LBM and poultry farms (2018-2019), as well as in Cameroon, Egypt and Siberia. A natural reassortant strain, identified in 2019 represents the third group: H5N8 viruses with the same gene constellation were identified in 2018 in South Africa. Finally, the fourth introduction represents the first detection in the African continent of the H5N6 subtype, which is related to European viruses. Bayesian phylogeographic analyses confirmed that the four introductions originated from different sources and provide evidence of the virus spread within Nigeria, as well as diffusion beyond its borders. The multiple epidemiological links between Nigeria, Central and Southern African countries highlight the need for harmonized and coordinated surveillance system to control AIV impact. Improved surveillance at the Wetlands, LBMs and early warning of outbreaks are crucial for prevention and control of AIV, which can be potentially zoonotic and be a threat to human health.
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Research Interests: Agriculture, Nigeria, Medicine, Humans, Birds, and 3 moreAnimals, Poultry, and Population surveillance
Since 2006, multiple outbreaks of avian influenza (AI) have been reported in Nigeria involving different subtypes. Surveillance and molecular epidemiology have revealed the vital role of live bird markets (LBMs) in the dissemination of AI... more
Since 2006, multiple outbreaks of avian influenza (AI) have been reported in Nigeria involving different subtypes. Surveillance and molecular epidemiology have revealed the vital role of live bird markets (LBMs) in the dissemination of AI virus to commercial poultry farms. To better understand the ecology and epidemiology of AI in Nigeria, we performed whole-genome sequencing of nineteen H9N2 viruses recovered, from apparently healthy poultry species, during active surveillance conducted in nine LBMs across Nigeria in 2019. Analyses of the HA gene segment of these viruses showed that the H9N2 strains belong to the G1 lineage, which has zoonotic potential, and are clustered with contemporary H9N2 identified in Africa between 2016 and 2020. We observed two distinct clusters of H9N2 viruses in Nigeria, suggesting different introductions into the country. In view of the zoonotic potential of H9N2 and the co-circulation of multiple subtypes of AI virus in Nigeria, continuous monitoring o...
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In December 2018, suspected outbreaks of equine influenza (EI) were observed in donkeys in Sokoto State, in the extreme northwest of Nigeria bordering the Republic of the Niger. Equine influenza virus (EIV) subtype H3N8 was the etiologic... more
In December 2018, suspected outbreaks of equine influenza (EI) were observed in donkeys in Sokoto State, in the extreme northwest of Nigeria bordering the Republic of the Niger. Equine influenza virus (EIV) subtype H3N8 was the etiologic agent identified in the outbreaks using real-time RT-qPCR and sequencing of both the partial haemagglutinin (HA) gene and the complete genome. Since then the H3N8 virus spread to 7 of the 19 northern states of Nigeria, where it affected both donkeys and horses. Phylogenetic analysis of the partial and complete HA gene revealed the closest nucleotide similarity (99.7%) with EIVs belonging to the Florida clade 1 (Fc-1) of the American lineage isolated in 2018 from Argentina and Chile. In total, 80 amino acid substitutions were observed in the viral proteins when compared to the OIE-recommended Fc-1 vaccine strains. The HA and neuraminidase proteins respectively had 13 and 16 amino acid substitutions. This study represents the first reported outbreak of EI caused by an Fc-1 virus in Nigeria and in the West Africa sub-region. Based on this report, extensive disease surveillance in equids is required to establish the circulating lineages and design an effective control strategy to protect the considerable population of horses and donkeys in the country.
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The role of Africa in the dynamics of the global spread of a zoonotic and economically-important virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD lineage, remains unexplored. Here we characterise the... more
The role of Africa in the dynamics of the global spread of a zoonotic and economically-important virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD lineage, remains unexplored. Here we characterise the spatiotemporal patterns of virus diffusion during three HPAI H5Nx intercontinental epidemic waves and demonstrate that Africa mainly acted as an ecological sink of the HPAI H5Nx viruses. A joint analysis of host dynamics and continuous spatial diffusion indicates that poultry trade as well as wild bird migrations have contributed to the virus spreading into Africa, with West Africa acting as a crucial hotspot for virus introduction and dissemination into the continent. We demonstrate varying paths of avian influenza incursions into Africa as well as virus spread within Africa over time, which reveal that virus expansion is a complex phenomenon, shaped by an intricate interplay between avian host ecology, virus characteristics and environmental variables.
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Newcastle disease virus (NDV) has a wide avian host range and a high degree of genetic variability, and virulent strains cause Newcastle disease (ND), a worldwide concern for poultry health. Although NDV has been studied in Nigeria,... more
Newcastle disease virus (NDV) has a wide avian host range and a high degree of genetic variability, and virulent strains cause Newcastle disease (ND), a worldwide concern for poultry health. Although NDV has been studied in Nigeria, genetic information about the viruses involved in the endemicity of the disease and the transmission that likely occurs at the poultry-wildlife interface is still largely incomplete. Next-generation and Sanger sequencing was performed to provide complete (n = 73) and partial genomic sequence data (n = 38) for NDV isolates collected from domestic and wild birds in Nigeria during 2002-2015, including the first complete genome sequences of genotype IV and subgenotype VIh from the African continent. Phylogenetic analysis revealed that viruses of seven different genotypes circulated in that period, demonstrating high genetic diversity of NDV for a single country. In addition, a high degree of similarity between NDV isolates from domestic and wild birds was observed, suggesting that spillovers had occurred, including to three species that had not previously been shown to be susceptible to NDV infection. Furthermore, the first spillover of a mesogenic Komarov vaccine virus is documented, suggesting a previous spillover and evolution of this virus. The similarities between viruses from poultry and multiple bird species and the lack of evidence for host adaptation in codon usage suggest that transmission of NDV between poultry and non-poultry birds occurred recently. This is especially significant when considering that some viruses were isolated from species of conservation concern. The high diversity of NDV observed in both domestic and wild birds in Nigeria emphasizes the need for active surveillance and epidemiology of NDV in all bird species.
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Globally, vaccines are used to prevent and control the menace of infectious diseases in livestock with some reported to be inadvertently contaminated with extraneous agents (EAs). With the aim of screening and characterizing for some... more
Globally, vaccines are used to prevent and control the menace of infectious diseases in livestock with some reported to be inadvertently contaminated with extraneous agents (EAs). With the aim of screening and characterizing for some selected EAs, 44 live viral poultry vaccines were randomly selected based on availability. The vaccines comprised 14 manufacturers in 10 different countries including Nigeria were screened by Polymerase Chain Reaction. In 9% (4/44) of the vaccines, contamination with only avian leukosis virus (ALV) subgroup J (ALV-J) was recorded. Other exogenous ALV subgroups, chicken infectious anemia and infectious laryngotracheitis viruses were absent. The EAs was found in infectious bursal disease (n = 1), Fowlpox (n = 2) and Mareks disease (n = 1) vaccines. Phylogenetic analysis of the ALV-J env gene showed clustering with contemporary group I and II. The result underscores the importance of screening vaccines to avoid the introduction and spread of EAs that could pose a threat to poultry production.
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Here, we present the draft genome sequences of five multidrug-resistant novel species strains isolated from a pigeon, a duck, and chickens from Nigeria in 2009.
Avian influenza viruses (AIV) potentially transmit to swine as shown by experiments, where further reassortment may contribute to the generation of pandemic strains. Associated risks of AIV inter-species transmission are greater in... more
Avian influenza viruses (AIV) potentially transmit to swine as shown by experiments, where further reassortment may contribute to the generation of pandemic strains. Associated risks of AIV inter-species transmission are greater in countries like Nigeria with recurrent epidemics of highly pathogenic AI (HPAI) in poultry and significant pig population. Analysis of 129 tracheal swab specimens collected from apparently healthy pigs at slaughterhouse during presence of HPAI virus H5N1 in poultry in Nigeria for influenza A by RT-qPCR yielded 43 positive samples. Twenty-two could be determined by clade specific RT-qPCR as belonging to the H5N1 clade 2.3.2.1c and confirmed by partial hemagglutinin (HA) sequence analysis. In addition, 500 swine sera were screened for antibodies against influenza A virus nucleoprotein and H5 HA using competition ELISAs and hemagglutination inhibition (HI) tests. Serologically, 222 (44.4%) and 42 (8.4%) sera were positive for influenza A virus NP and H5 antib...
Phylogenetic analyses of the complete genomes of the highly pathogenic avian influenza (HPAI) 2.3.2.1c H5N1 virus strains causing outbreaks in Nigeria's poultry population from 2014 to 2016 showed evidence of distinct co-circulating... more
Phylogenetic analyses of the complete genomes of the highly pathogenic avian influenza (HPAI) 2.3.2.1c H5N1 virus strains causing outbreaks in Nigeria's poultry population from 2014 to 2016 showed evidence of distinct co-circulating genotypes and the emergence of reassortant viruses. One of these reassortants became the predominant strain by 2016, and the NA protein of this strain possessed the V96A substitution known to confer reduced susceptibility to neuraminidase inhibiting antiviral drugs. Our findings also demonstrated evolutionary relationships between Nigerian isolates and European and Middle Eastern strains of H5N1 which provides further evidence for the proposed role of migratory birds in spreading the virus, although the involvement of the live poultry trade cannot be excluded. Efforts must be directed towards improving biosecurity and gaining the cooperation of poultry farmers for more effective control of HPAI, in order to mitigate the emergence of HPAI strains in N...
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Next-generation sequencing (NGS) allows ultra-deep sequencing of nucleic acids. The use of sequence-independent amplification of viral nucleic acids without utilization of target-specific primers provides advantages over traditional... more
Next-generation sequencing (NGS) allows ultra-deep sequencing of nucleic acids. The use of sequence-independent amplification of viral nucleic acids without utilization of target-specific primers provides advantages over traditional sequencing methods and allows detection of unsuspected variants and co-infecting agents. However, NGS is not widely used for small RNA viruses because of incorrectly perceived cost estimates and inefficient utilization of freely available bioinformatics tools. In this study, we have utilized NGS-based random sequencing of total RNA combined with barcode multiplexing of libraries to quickly, effectively and simultaneously characterize the genomic sequences of multiple avian paramyxoviruses. Thirty libraries were prepared from diagnostic samples amplified in allantoic fluids and their total RNAs were sequenced in a single flow cell on an Illumina MiSeq instrument. After digital normalization, data were assembled using the MIRA assembler within a customized...
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Genetic analysis of the complete haemagglutinin (HA) gene of fourteen Nigerian avian influenza isolates showed multiple basic amino acids at the cleavage site ((321)PQRERRRK (del) R*GLF(333)), characteristic of highly pathogenic avian... more
Genetic analysis of the complete haemagglutinin (HA) gene of fourteen Nigerian avian influenza isolates showed multiple basic amino acids at the cleavage site ((321)PQRERRRK (del) R*GLF(333)), characteristic of highly pathogenic avian influenza (HPAI). Substitution of Gln to Lys at position 322 (H5-specific numbering) was identified in one isolate. In some isolates, amino acid substitutions were observed across the HA gene, however the receptor binding, antigenic and glycosylation sites were conserved in all. Phylogenetic analysis revealed two clusters of the HPAI H5N1 clade 2.3.2.1c. Cluster I has close genetic relatedness (97.8-99.8%) with viruses circulating in some West Africa countries. Cluster II shared close identity (98.9-100.0%) with isolates from Europe, Côte d&amp;amp;amp;amp;#39;Ivoire and Niger and viruses from this cluster were detected in five of the eleven states investigated in Nigeria. In view of the continuous HPAI outbreaks being recorded in Nigerian poultry and the zoonotic potential of the virus, extensive and continued characterization of HPAI isolates is advocated.
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Infectious laryngotracheitis (ILT) is a highly contagious acute respiratory disease of chickens with outbreaks resulting in high economic losses due to increased mortality and drop in egg production. This study reports a survey of ILT... more
Infectious laryngotracheitis (ILT) is a highly contagious acute respiratory disease of chickens with outbreaks resulting in high economic losses due to increased mortality and drop in egg production. This study reports a survey of ILT virus antibody conducted in nine local government areas (LGAs) of Plateau State involving 67 randomly selected commercial poultry flocks. In all, 938 sera were tested using the Agar Gel Immuno-diffusion (AGID) technique. Overall prevalence of 1.2% (N = 11) was recorded. ILT virus antibody was found in 2.5% (n = 9) and 7.1% (n = 2) of the tested sera from Jos South and Langtang North LGAs, respectively. No detectable ILT virus antibody was found from the other seven LGAs. This is the first report of ILT infection in poultry from the North central part of Nigeria. It is therefore recommended that the economic implication of ILT infection in Nigerian poultry population be conducted in order to know if vaccination should be adopted for control.
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The first complete genome sequence of a strain of Newcastle disease virus (NDV) of genotype XVII is described here. A velogenic strain (duck/Nigeria/903/KUDU-113/1992) was isolated from an apparently healthy free-roaming domestic duck... more
The first complete genome sequence of a strain of Newcastle disease virus (NDV) of genotype XVII is described here. A velogenic strain (duck/Nigeria/903/KUDU-113/1992) was isolated from an apparently healthy free-roaming domestic duck sampled in Kuru, Nigeria, in 1992. Phylogenetic analysis of the fusion protein gene and complete genome classified the isolate as a member of NDV class II, genotype XVII.
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The first complete genome sequence of a strain of Newcastle disease virus (NDV) from genotype XIV is reported here. Strain duck/Nigeria/NG-695/KG.LOM.11-16/2009 was isolated from an apparently healthy domestic duck from a live bird market... more
The first complete genome sequence of a strain of Newcastle disease virus (NDV) from genotype XIV is reported here. Strain duck/Nigeria/NG-695/KG.LOM.11-16/2009 was isolated from an apparently healthy domestic duck from a live bird market in Kogi State, Nigeria, in 2009. This strain is classified as a member of subgenotype XIVb of class II.
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The effect of four commonly employed infectious bursal disease (IBD) vaccines on the immune response of chickens vaccinated with Newcastle disease (ND) vaccine were assessed in pullets using a pre-existing vaccination regimen, depicting... more
The effect of four commonly employed infectious bursal disease (IBD) vaccines on the immune response of chickens vaccinated with Newcastle disease (ND) vaccine were assessed in pullets using a pre-existing vaccination regimen, depicting field situations. The antibodies to IBD was evaluated by the qualitative and quantitative agar gel immunodiffusion method while the haemagglution inhibition (HI) test was used for the detection of ND antibodies. The immunosuppressive effect was assessed by: the suppression of the ND titres; the bursa of Fabricius (BF) index; the BF diameter; and the BF histopathological lesions. The results showed that the IBD vaccines caused a transient immunosuppression in the ND vaccinated chicks. This immunosuppressive effect was non existent when a booster dose of Newcastle disease — Komarov vaccine (NDV-K) was administered. Both the BF index and diameter were significantly higher (P < 0.05) in the vaccinated groups when compared with the control unvaccinated...
The haemagglutination binding pattern of some Nigerian isolates of HPAI H5N1 to selected erythrocytes of mammalian and avian origin was investigated. Fifteen isolates of the virus from 8 states in Nigeria were tested using rapid... more
The haemagglutination binding pattern of some Nigerian isolates of HPAI H5N1 to selected erythrocytes of mammalian and avian origin was investigated. Fifteen isolates of the virus from 8 states in Nigeria were tested using rapid haemagglutination (RHA) test against five mammalian and five avian erythrocytes. Erythrocytes of human, dog, chicken, turkey, quail, geese and duck were agglutinated by all the isolates while cow and horse erythrocytes were agglutinated by 14 of the isolates. On the contrary, none of the isolates agglutinated pig erythrocytes. Further investigation with erythrocytes from 4 different breeds of pigs showed similar pattern of non-agglutination. This work shows that pig erythrocytes has poor or no affinity for Nigerian isolates of HPAI which may suggest low expression or lack of receptors for HPAI in this species. Further work is required to determine the molecular basis for this variation
The highly pathogenic avian influenza (H5N1 subtype) recurred in Nigeria after 9 months period of no reported case. A critical look at possible sources of the re-occurrence was desirable. The objective of this study was to determine... more
The highly pathogenic avian influenza (H5N1 subtype) recurred in Nigeria after 9 months period of no reported case. A critical look at possible sources of the re-occurrence was desirable. The objective of this study was to determine whether avian influenza viruses were present at reasonably detectable levels (0.5%) in possible “bridge” species of wild and domestic birds. The study was conducted in 8 Nigerian states. A total of 403 birds from 40 species were sampled. Virus isolation was done in embryonated chicken eggs according to standard protocols. The test results were all negative for avian influenza viruses. The overall confidence interval (CI) calculated in R using the exact binomial confidence interval function was 0–0.007406. Tawny Eagle (Aquila rapax) was the lowest sampled 0.3% (1/403) and Red-billed Firefinch (Lagonosticta senegala) the highest 11.7% (47/403). The limitations of the sample size and possibly designing effects on the study, as to make concrete conclusions w...
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We genetically analyzed field isolates of the Newcastle disease (ND) virus isolated in Japan from 1930 to 2001. The coding region of the fusion protein was amplified by reverse transcriptase PCR and directly sequenced. Phylogenetic... more
We genetically analyzed field isolates of the Newcastle disease (ND) virus isolated in Japan from 1930 to 2001. The coding region of the fusion protein was amplified by reverse transcriptase PCR and directly sequenced. Phylogenetic analysis revealed the presence of viruses belonging to six of the eight known genotypes. It can be concluded from this study that ND outbreaks in Japan have been of multiple etiologies.
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Research Interests: Molecular Evolution, Medical Microbiology, Infectious Diseases, Emerging Infectious Diseases, Middle East, and 10 moreMolecular Epidemiology, Phylogeny, Europe, Birds, Animals, Molecular Phylogenetics and Evolution, Genome, Clinical Sciences, Public health systems and services research, and Molecular Sequence Data
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Genetic characterization of a selection of infl uenza virus (H5N1) samples, circulating in 8 Nigerian states over a 39-day period in early 2007, indicates that a new reassortant strain is present in 7 of the 8 states. Our study reports an... more
Genetic characterization of a selection of infl uenza virus (H5N1) samples, circulating in 8 Nigerian states over a 39-day period in early 2007, indicates that a new reassortant strain is present in 7 of the 8 states. Our study reports an entirely different infl uenza virus (H5N1) reassortant becoming predominant and widespread in poultry. Since its emergence in 2006 in Africa, avian influenza viruses of the H5N1 subtype have spread rapidly to poultry farms in several African countries. In February 2006, Kaduna State in Nigeria was the first of 36 states to report infection of poultry with highly pathogenic avian influenza virus (H5N1). Currently, infection has spread to 22 of the 36 Nigerian states and to the Federal Capital Territory. In February 2007, 1 case of avian influenza was reported in a woman from the southern state of Lagos. Thus, the extensive circulation of influenza virus (H5N1) in Nigeria raises concerns about human and animal health issues. A previous study indicate...
Progressive loss of virulence for goat kids was noticed when peste des petits ruminants (PPR) virus was passaged in Vero cells. While goats inoculated with the 60th passage suffered from the clinical PPR disease and mortality, goats... more
Progressive loss of virulence for goat kids was noticed when peste des petits ruminants (PPR) virus was passaged in Vero cells. While goats inoculated with the 60th passage suffered from the clinical PPR disease and mortality, goats inoculated with the 80th passage did not show any sign of the disease. If the progressive loss of virulence of the virus with passage continues, it will not be long before a homologous PPR vaccine will be obtained at the National Veterinary Institute, Vom.