Browsing by Author "Okewole, Philip"

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    Clinico-Pathological Features of Highly Pathogenic Avian Influenza (HPAI-H5N1) Outbreaks in Commercial Chickens in Nigeria
    (Vom Journal of Veterinary Science, 2006) Kumbish, Peterside; Joannis, Tony; Jambalang, Alex; Damina, M; Hussaini, Bakare; Akanbi, Olatunde Babatunde; Oyetunde, I; Abdu, M; Danbirni, S; James, Ahmed; Yahaya, K; Bako, Ben; Nanbol, Daniel; Elisha, I; Solomon, Ponman; Ogunsan, E; Adulugba, A; Okewole, Philip
    In early January 2006, the first confirmed oubreaks of avian influenza in domestic birds occurred in the commercial chicken flocks in Kaduna, Jos and Kano States in the northern part of Nigeria. The outbreaks were confirmed to be the highly pathogenic avian influenza (HPAI) caused by the subtype H5N1. The outbreak was spontaneously reported in Jos, and about 10 days later it was reported in Kano and it quickly spread to other parts of the country. The infection was characterized by very high mortality in commercial layers. It was also observed to affect turkeys, broilers, cockerels, backyard/local chickens, ostriches, pigeons, guinea fowls, geese and ducks. The gross and microscopic lesions were found to similar to what have been described earlier for the disease.
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    Formalin-Fixed and Paraffin-Embedded Tissues of Chickens are Useful for Retrospective Studies on Pathology of H5N1 Highly Pathogenic Avian Influenza Virus (HPAI) Outbreaks in Nigeria
    (Nigerian Veterinary Journal, 2017) Akanbi, Olatunde; Fereidouni, Sesan; Taiwo, Victor; Starick, Elke; Okewole, Philip; Binder, Alfred; Heenemann, Kristin; Teifke, Jens
    In a retrospective study, histopathology and immunohistochemistry (IHC) were performed on formalin-fixed paraffin embedded (FFPE) archival tissues from chickens obtained during outbreaks of highly pathogenic avian influenza (HPAI) H5N1 that occurred in Nigeria in 2006 and 2007. Ten samples as representative of 10 outbreaks were selected, and following the detection of HPAI viral antigen in different chicken tissues using IHC, RNA was extracted from each sample and molecular analysis was performed using real-time reverse transcription-polymerase chain reaction (rRT-PCR) targeting matrix protein. Seven rRT-PCR positive samples were then subjected to conventional and rRT-PCR assays for the amplification of hemagglutinin (HA) gene. Four of them were further characterized by sequence analysis of a short HA2-part of the H5 gene. Along the 154 nucleotides sequenced, differences at 4 positions were detected in one sample. One of these mutations led to an amino acid exchange at position 544 (Ala>Thr) whereas the others were silent. The study suggests the potential application for retrospective IHC and PCR analysis of FFPE tissues from chickens involved in the AI outbreaks for pathologic studies and providing short fragment sequences which may help in the characterization of viral strains and tracing the outbreaks. This is important as archived poultry tissues can be re-examined for possibility of earlier introduction of the virus.