Dengue haemorrhagic fever: An emerging disease in Nigeria, West Africa

Introduction: In Nigeria, dengue fever caused by dengue virus, types 1 and 2 has been diagnosed for many years. Although, seroepidemiological surveys have shown that dengue virus activity is, widespread in the country, there is scanty information on dengue, hemorrhagic fever with little attention paid to dengue fever largely, because it presents as classical dengue fever characterized by fever, myalgia, headache, arthralgia, retro-orbital pain, gastro intestinal, symptoms and skin rash. We are updating the current information of dengue, in Nigeria, as well as DHF which is an emerging disease in the west, African country. Methods: PUBMED, Google scholar, cross-reference databases and individual publications not publicly archived were used. All available literature on, dengue from Nigeria were identified. Results: Dengue virus 3 and 4 have been recently detected in Nigeria, with the emergence of dengue haemorrhagic fever for the first time. Poor, surveillance, underreporting, and misdiagnosis of the disease as malaria, are major problems. Conclusion: Priority must be given to increasing surveillance activity to, detect more dengue haemorrhagic fever cases and determine the magnitude, of the dengue problem. It is important to enhance the capacity of, laboratories to diagnose dengue haemorrhagic fever by providing them with, modern equipment, reagents and new infrastructure. Keywords: Dengue haemorrhagic fever, Emerging disease, Nigeri

Single nucleotide polymorphisms (SNPs) in the open reading frame (ORF) of prion protein gene (PRNP) in Nigerian livestock species

Abstract Background Prion diseases, also known as transmissible spongiform encephalopathies (TSEs) remain one of the deleterious disorders, which have affected several animal species. Polymorphism of the prion protein (PRNP) gene majorly determines the susceptibility of animals to TSEs. However, only limited studies have examined the variation in PRNP gene in different Nigerian livestock species. Thus, this study aimed to identify the polymorphism of PRNP gene in Nigerian livestock species (including camel, dog, horse, goat, and sheep). We sequenced the open reading frame (ORF) of 65 camels, 31 village dogs and 12 horses from Nigeria and compared with PRNP sequences of 886 individuals retrieved from public databases. Results All the 994 individuals were assigned into 162 haplotypes. The sheep had the highest number of haplotypes (n = 54), and the camel had the lowest (n = 7). Phylogenetic tree further confirmed clustering of Nigerian individuals into their various species. We detected five non-synonymous SNPs of PRNP comprising of G9A, G10A, C11G, G12C, and T669C shared by all Nigerian livestock species and were in Hardy-Weinberg Equilibrium (HWE). The amino acid changes in these five non-synonymous SNP were all “benign” via Polyphen-2 program. Three SNPs G34C, T699C, and C738G occurred only in Nigerian dogs while C16G, G502A, G503A, and C681A in Nigerian horse. In addition, C50T was detected only in goats and sheep. Conclusion Our study serves as the first to simultaneously investigate the polymorphism of PRNP gene in Nigerian livestock species and provides relevant information that could be adopted in programs targeted at breeding for prion diseases resistance

Polymorphism of prion protein gene (PRNP) in Nigerian sheep

ABSTRACTPolymorphism of the prion protein gene (PRNP) gene determines an animal’s susceptibility to scrapie. Three polymorphisms at codons 136, 154, and 171 have been linked to classical scrapie susceptibility, although many variants of PRNP have been reported. However, no study has investigated scrapie susceptibility in Nigerian sheep from the drier agro-climate zones. In this study, we aimed to identify PRNP polymorphism in nucleotide sequences of 126 Nigerian sheep by comparing them with public available studies on scrapie-affected sheep. Further, we deployed Polyphen-2, PROVEAN, and AMYCO analyses to determine the structure changes produced by the non-synonymous SNPs. Nineteen (19) SNPs were found in Nigerian sheep with 14 being non-synonymous. Interestingly, one novel SNP (T718C) was identified. There was a significant difference (P < 0.05) in the allele frequencies of PRNP codon 154 between sheep in Italy and Nigeria. Based on the prediction by Polyphen-2, R154H was probably damaging while H171Q was benign. Contrarily, all SNPs were neutral via PROVEAN analysis while two haplotypes (HYKK and HDKK) had similar amyloid propensity of PRNP with resistance haplotype in Nigerian sheep. Our study provides valuable information that could be possibly adopted in programs targeted at breeding for scrapie resistance in sheep from tropical regions