Genomic Analysis of Infectious Bursal Disease Virus in Nigeria: Identification of Unique Mutations of Yet Unknown Biological Functions in Both Segments A and B.

Infectious bursal disease (IBD) is a viral poultry disease known worldwide for impacting the economy and food security. The disease is endemic in Nigeria, with reported outbreaks in vaccinated poultry flocks. To gain insight into the dynamics of infectious bursal disease virus (IBDV) evolution in Nigeria, near-complete genomes of four IBDVs were evaluated. Amino acid sequences in the hypervariable region of the VP2 revealed conserved markers (222A, 242I, 256I, 294I and 299S) associated with very virulent (vv) IBDV, including the serine-rich heptapeptide motif (SWSASGS). Based on the newly proposed classification for segments A and B, the IBDVs clustered in the A3B5 group (where A3 are IBDVs with vvIBDV-like segment A, and where B5 are from non-vvIBDV-like segment B) form a monophyletic subcluster. Unique amino acid mutations with yet-to-be-determined biological functions have been observed in both segments. Amino acid sequences of the Nigerian IBDVs showed that they are reassortant viruses. Circulation of reassortant IBDVs may be responsible for the vaccination failures observed in the Nigerian poultry population. Close monitoring of changes in the IBDV genome is recommended to nip deleterious changes in the bud through the identification and introduction of the most appropriate vaccine candidates and advocacy/extension programs for properly implementing disease control.

Avian leukosis virus subgroup - J as a contaminant in live commercially available poultry vaccines distributed in Nigeria.

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.

Molecular characterization of field infectious bursal disease virus isolates from Nigeria.

AIM: To characterize field isolates of infectious bursal disease virus (IBDV) from outbreaks in nine states in Nigeria through reverse transcription polymerase chain reaction (RT-PCR) and sequence analysis of portions of the VP2 and VP1 genes and to determine the presence or absence of reassortant viruses. MATERIALS AND METHODS: A total of 377 bursa samples were collected from 201 suspected IBD outbreaks during 2009 to 2014 from nine states in Nigeria. Samples were subjected to RT-PCR using VP2 and VP1 gene specific primers, and the resulting PCR products were sequenced. RESULTS: A total of 143 samples were positive for IBDV by RT-PCR. These assays amplified a 743 bp fragment from nt 701 to 1444 in the IBDV VP2 hypervariable region (hvVP2) of segment A and a 722 bp fragment from nt 168 to 889 in the VP1 gene of segment B. RT-PCR products were sequenced, aligned and compared with reference IBDV sequences obtained from GenBank. All but one hvVP2 sequence showed similarity to very virulent IBDV (vvIBDV) reference strains, yet only 3 of the VP1 67 VP1 sequences showed similarity to the VP1 gene of vvIBDV. Phylogenetic analysis revealed a new lineage of Nigerian reassortant IBDV strains. CONCLUSION: Phylogenetic analysis of partial sequences of genome segment A and B of IBDV in Nigeria confirmed the existence of vvIBDV in Nigeria. In addition, we noted the existence of reassortant IBDV strains with novel triplet amino acid motifs at positions 145, 146 and 147 in the reassorted Nigerian IBDV.

Hepatitis C Virus infection in apparentenly healthy individuals with family history of diabetes in Vom, Plateau State Nigeria.

Hepatitis C virus (HCV) infection is an important public health problem worldwide. Its association with, and predisposing nature for diabetes mellitus (DM) has been long established. This research was carried out to determine the prevalence of Hepatitis C virus (HCV) amongst people with possible genetic predisposition to diabetes mellitus living in and around Vom, Plateau State, Nigeria. 188 subjects were screened after they filled a structured questionnaire to determine some of their demographic data, social habits and possible risk factors. 5 ml of blood was collected from each subject and sera separated out. Biotech's third generation ELISA Kit for HCV antibodies was used for the screening. Liver enzyme analysis was carried out on positive samples to determine their disease status. A prevalence of 14.36% was recorded with the highest seropositive group being those in the age bracket of 18 - 37 years. 13(13.40%) of males and 14(15.38%) of females were sero-positive. Liver enzyme analysis of sero-positive subjects showed increased levels which may imply early onset of liver damage. These result showed that these individuals could later suffer diabetes which may be triggered by their HCV infection if not treated. This is not over-looking the economic significance of their ill health, assuming they progress to cirrhotic HCV or develop hepatocelluar carcinoma due to HCV chronicity.