FLOCK-BASED SURVEILLANCE FOR LOW PATHOGENIC AVIAN INFLUENZA VIRUS IN COMMERCIAL BREEDERS AND LAYERS, SOUTHWEST NIGERIA

Background: Flock surveillance systems for avian influenza (AI) virus play a critical role in countries where vaccination is not practiced so as to establish the epidemiological characteristics of AI needed for the development of prevention and control strategies in such countries. Materials and Methods: As part of routine AI monitoring in southwest Nigeria, a competitive ELISA was used for detecting influenza A virus antibodies in the sera of 461 commercial breeder and layer birds obtained from different flocks in Oyo State, Nigeria while haemagglutination inhibiting antibodies against low pathogenic AI viruses (LPAIVs) were detected using H5N2, H7N7 and H9N2 subtype-specific antigens. Suspensions prepared from cloacal swabs were tested for AI virus RNA using reverse transcriptase-polymerase chain reaction. Results: Results showed that influenza A virus antibody prevalence was 12.8% and 9.3% for breeders and layers, respectively while HI assay revealed 22.0%, 2.0% and 78.0% prevalence of LPAIV H5N2, H7N7 and H9N2 antibodies respectively. All cloacal swab suspensions were negative for AIV RNA. Conclusion: Since LPAI infections result in decreased or complete cessation of egg production in breeder and layer birds, increased infection severity due to co-infection with other poultry viruses have occasionally been transmitted to humans, the detection of LPAIV H5N2, H7N7 and H9N2 antibodies in these birds is of both economic and public health significance. These findings underscore the need for continuous flock monitoring as part of early warning measure to facilitate rapid detection and sustainable control of AI in Nigerian poultry

Phylogenetics and Pathogenesis of Early Avian Influenza Viruses (H5N1), Nigeria

Three highly pathogenic avian influenza subtype H5N1 and 4 Newcastle disease viruses were isolated from sick or dead chickens in southwestern Nigeria. Sequencing and phylogenetic analysis placed them within H5N1 subclade 2.2.2. Intravenous and intranasal pathogenicity tests produced systemic disease with vascular endothelial cell tropism in chickens

Computational Biology and Bioinformatics in Nigeria

Over the past few decades, major advances in the field of molecular biology, coupled with advances in genomic technologies, have led to an explosive growth in the biological data generated by the scientific community. The critical need to process and analyze such a deluge of data and turn it into useful knowledge has caused bioinformatics to gain prominence and importance. Bioinformatics is an interdisciplinary research area that applies techniques, methodologies, and tools in computer and information science to solve biological problems. In Nigeria, bioinformatics has recently played a vital role in the advancement of biological sciences. As a developing country, the importance of bioinformatics is rapidly gaining acceptance, and bioinformatics groups comprised of biologists, computer scientists, and computer engineers are being constituted at Nigerian universities and research institutes. In this article, we present an overview of bioinformatics education and research in Nigeria. We also discuss professional societies and academic and research institutions that play central roles in advancing the discipline in Nigeria. Finally, we propose strategies that can bolster bioinformatics education and support from policy makers in Nigeria, with potential positive implications for other developing countries. © 2014 Fatumo et al.SAF was supported by H3ABioNet NABDA Node, Abuja, Nigeria with NIH Common Fund Award/NHGRI Grant Number U41HG006941 and Genetic Epidemiology Group at Wellcome Trust Sanger Institute.Published versio

Role of Position 627 of PB2 and the Multibasic Cleavage Site of the Hemagglutinin in the Virulence of H5N1 Avian Influenza Virus in Chickens and Ducks

Highly pathogenic H5N1 avian influenza viruses have caused major disease outbreaks in domestic and free-living birds with transmission to humans resulting in 59% mortality amongst 564 cases. The mutation of the amino acid at position 627 of the viral polymerase basic-2 protein (PB2) from glutamic acid (E) in avian isolates to lysine (K) in human isolates is frequently found, but it is not known if this change affects the fitness and pathogenicity of the virus in birds. We show here that horizontal transmission of A/Vietnam/1203/2004 H5N1 (VN/1203) virus in chickens and ducks was not affected by the change of K to E at PB2-627. All chickens died between 21 to 48 hours post infection (pi), while 70% of the ducks survived infection. Virus replication was detected in chickens within 12 hours pi and reached peak titers in spleen, lung and brain between 18 to 24 hours for both viruses. Viral antigen in chickens was predominantly in the endothelium, while in ducks it was present in multiple cell types, including neurons, myocardium, skeletal muscle and connective tissues. Virus replicated to a high titer in chicken thrombocytes and caused upregulation of TLR3 and several cell adhesion molecules, which may explain the rapid virus dissemination and location of viral antigen in endothelium. Virus replication in ducks reached peak values between 2 and 4 days pi in spleen, lung and brain tissues and in contrast to infection in chickens, thrombocytes were not involved. In addition, infection of chickens with low pathogenic VN/1203 caused neuropathology, with E at position PB2-627 causing significantly higher infection rates than K, indicating that it enhances virulence in chickens

Nucleotide and Amino acid changes map to Functional Domains on the Haemagglutinin of A/equine/Ibadan/4/91 (H3N8) influenza virus

The application of the method of rapid sequencing of equine influenza A virus A/equine/Ibadan/4/91 (H3N8) haemagglutinin (HA) gene in ELISA plates is reported. There was no nucleotide change compared with the sequence we earlier obtained for this virus by cycle sequencing which indicates that the present method is equally sensitive and specific but there was only one nucleotide change at position 478 compared to A/eq/Ibadan/6/91 (H3N8) isolated at the same time. Compared with prototype European strain, A/eq/Suffolk/89 (H3N8), nucleotide and amino acid changes observed in the HA of A/eq/Ibadan/4/91 mapped to functional domains of the molecule: signal peptide and antigenic sites. Nucleotide changes occurred at positions 45 (A→G), 478 (G→C), 562 (T→G), 805 (C→T) in HA1 and 1188 (G→A) in HA2 while amino acid changes occurred at residues 6 (I→V) in the signal peptide, 135 (R→T), 178 (I→T), 244 (T→M) in the HA1 and 43 (A→T) in the HA2. The change at residue 135 introduced a new potential asparagine-linked glycosylation site at residue 133. The genetic and antigenic implications of these changes are highlighted. The specificity and advantages of the method used over reverse transcription-polymerase chain reaction (RT-PCR) and cycle sequencing of PCR products are discussed

The water quality and sanitary conditions in a major Abattoir (Bodija) in Ibadan, Nigeria

Twelve wells were assessed using their physico-chemical and bacteriological parameters as indices.The organoleptic properties including appearance, odour and taste were used for the physical assessment while flame photometry, atomic absorption spectrophotometer, titration, gravimetry and evaporation to dryness were used to determine the chemical constituents and the serial dilution technique used in determining the total bacterial count, coliform count and faecal streptococcus count. Biochemical tests were carried out to further characterize the organisms isolated. The sanitary conditions on the slaughter slabs and within the abattoir grounds was also assessed to determine the effect on the water quality of the wells used in dressing carcasses and other activities. All the wells sampled were clear and without colour, odour and taste with PH and temperature values ranging between 6.41 – 6.75 and 24.5oc – 28.4oc respectively. The mean values obtained in the samples from groups A, B and C for calcium, magnesium, sodium, potassium, zinc and copper were all within the WHO, 1971; 1995 recommendations while the iron, (3.00mg/L); Lead (0.09mg/L); chloride (312.07mg/L) and total solid (2100.00mg/L) in group A samples exceeded the recommended values of 0.1-1.00mg/L; 0.05mg/L; 200mg/L and 500-1500mg/L respectively. Results from the bacteriological analysis indicates that samples from wells A and B were highly contaminated with pathogenic bacteria including Escherichia coli, Pseudomonas aeruginosa, Bacillus substilis, Enterobacter aerogenes and faecal streptococcus, with group A having the highest mean bacterial count (15.4x104) and group C having the least (2.0X104). No pathogenic bacteria were isolated from samples in group C. The activities within the abattoir were being carried out in a most unhygienic manner. The public health importance of using contaminated water in dressing carcasses and other activities including consumption of the water without any form of treatment by butchers and abattoir workers and the implications of the sanitary condition of the abattoir on the water quality are discussed in the text

Serological screening for porcine Japanese B encephalitis virus among commercial pigs in an urban abattoir in southwest Nigeria

The inter-continental spread of Japanese encephalitis virus (JEV) to non-endemic regions is a continual impending threat with pigs implicated to play a major role in its transmission. Hence, the seroprevalence of the virus in pigs in a particular location is of utmost importance in the detection and control of the disease in a naïve population. A serological screening for JEV in slaughtered pigs at an urban abattoir in Ibadan, southwest Nigeria was conducted. Sera from 364 apparently healthy pigs were analyzed for the presence of JEV antibodies using a commercial ELISA kit. The results showed that none of the pigs had optimal JEV antibody titres, 42 (11.5%) had sub-optimal antibody levels while 322 (88.5%) were negative. Detection of sub-optimal JEV antibody levels in these unvaccinated pigs suggests exposure to JEV or related viruses. Also, drainages with dirt and stagnant water suitable for mosquito breeding were observed in this study. Considering that mosquito vector- and pig to pig- transmissions of JEV have been reported, these pigs, although with sub-optimal antibody levels can act as potential environmental source and play a role in transmission cycle of the virus in the study area. This therefore calls for continuous monitoring of the disease in pigs in Nigeria

Detection of IgG and/or IgM antibodies against equine infectious anaemia virus (EIAV) in Nigerian race and polo horses

Equine infectious anaemia (EIA) has aroused a lot of attention over the years. The disease is often fatal in horses and surviving horses remain lifelong carriers; that is why humane destruction of infected horses is highly recommmended. It is caused by the prototype lentivirus of the family retrovirus. A serological screening was carried out in polo and race horses from three selected state capitals in Nigeria. In all, 84 sera samples were collected from race horses from Ilorin in the North Central and Sokoto in the Northwest, and polo horses from Ibadan in the Southwest. They were analyzed for antibodies against the equine infectious anaemia virus (EIAV) by indirect ELISA. Of the 84 samples tested, 2 samples, 1 (1.2%) horse in Ilorin and 1 (1.2%) horse in Ibadan tested positive. It was observed that the positive horses were adult and they showed no fever and symptoms associated with EIA. The positive results were from male and female Arewa breed respectively. In conclusion, EIA is present in certain areas in Nigeria with prevalent of 2.4% among the Arewa breed horses from the population sampled.Keywords: Antibody, EIA, ELISA, Horse, Nigeri

Molecular detection and characterization of infectious laryngotracheitis virus in apparently healthy commercialand backyard chickens in Ibadan, Nigeria

Infectious laryngotracheitis (ILT) is an acute respiratory disease of chickens which often results in severe losses in the commercial poultry industry as well as backyard chicken flocks. It is also a latent viral infection of chickens worldwide and the causative virus can be shed through poultry droppings. To check if apparently healthy Nigerian commercial and backyard chickens shed the ILT virus, Polymerase Chain Reaction (PCR) was used to test for the presence of the virus Infected Cell Protein 4 (ICP4) gene in cloacal swabs from 45 commercial and 40 backyard chickens in Ibadan. Nested-PCR was used to probe the samples further for presence of the ICP4 gene. Moreover, two positive nested-PCR products from the backyard chicken samples were sequenced to characterize the virus. One (2.2%) of the 45 samples from commercial chickens and four (10%) of the 40 samples from backyard chickens were positive for the virus with the first round PCR. Six (13%) out of the 45 samples from commercial chickens and 12 (30%) out of the 40 from backyard chickens were positive with nested-PCR. Sequence analysis of the two nested-PCR products from the backyard chicken samples revealed that the Nigerian ILTV sequences had nonsynonymous mutations W1130K and S1135T. This study revealed that commercial and backyard chickens in Ibadan shed the virus with the possibility of spread of infection to other birds. The mutations and phylogenetic clustering of the Nigerian ILTV ICP4 partial sequences revealed that they are different from vaccine and reference field sequences from other countries

Prevalence of Avian Origin H5 and H7 Influenza Virus Antibodies in Dogs in Ibadan and Sagamu, Southwestern Nigeria

Highly pathogenic avian influenza H5N1 subtype was recently reported in some states of Southwestern Nigeria including Oyo and Ogun states. As part of ongoing influenza surveillance efforts in livestock and companion animals in Nigeria, a study was conducted to investigate the prevalence of avian H5 and H7 influenza virus antibodies in exotic and Nigerian village dogs in Ibadan and Sagamu, two cities in Oyo and Ogun states respectively. One hundred and sixty two (162) dogs comprising 85 exotic dogs from Ibadan and 77 Nigerian village dogs from Ibadan and Sagamu were screened for the presence of avian H5 and H7 influenza virus antibodies. Using the hemagglutination inhibition (HI) test, none of the samples from exotic dogs had HI antibodies to both virus strains while all 77 Nigerian village dog samples were negative for H5 antibodies but two (2.6%) were positive for H7 antibodies at a titre of 1:32. The presence of H7 influenza virus antibodies in Nigerian village dogs, although at a low rate, suggests that these dogs had naturally been infected with the virus. It is possible that the dogs acquired the infection through consumption of dead chickens or internal organs of animals killed during hunting. The close contact between these dogs and their owners, domestic poultry and wildlife underscores their importance in the epidemiology of influenza in Nigeria