45 research outputs found

    High prevalence of hepatitis B virus among female sex workers in Nigeria

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    Hepatitis B virus (HBV) infection is endemic in Nigeria and constitutes a public health menace. The prevalence of HBV infection in many professional groups has been described in Nigeria. However, literature on HBV infection among female sex workers (FSW) in Nigeria is scanty. FSW in Nigeria are not subjected to a preventive control of HBV infection. This study assesses the extent of spread of HBV among FSW in Nigeria. Seven hundred and twenty (n = 720) FSW (mean age = 26.7 years) were tested for hepatitis B surface antigen (HBsAg) by a double antibody sandwich ELISA method. The overall HBV prevalence among the FSW was 17.1%. FSWs between the ages of 31-35 year (20.5%) and those with 'age-at-first-sex' below 10 years of age (28%) were most affected. This high prevalence of a vaccine preventable disease is unacceptable, therefore, vaccination of this high risk HBV reservoir group should be considered worthwhile.A hepatite pelo vírus B (HBV) é infecção endêmica na Nigéria e constitui problema de saúde pública. A prevalência da infecção HBV em muitos grupos profissionais foi descrito na Nigéria. No entanto, a literatura da infecção HBV entre trabalhadoras do sexo feminino (FSW) na Nigéria é escasso. FSW na Nigéria não são submetidas a um controle preventivo de infecção de HBV. Este estudo avalia a extensão da disseminação de HBV entre FSW na Nigéria. Setecentos e vinte (n = 720) FSW (média de idade = 26,7 anos) foram testadas para antígeno de superfície da hepatite B (HBsAg) pelo método ELISA usando sandwich de duplos anticorpos. A prevalência total de HBV entre o FSW foi 17,1%. FSWs entre as idades de 31-35 anos (20,5%) e abaixo de 10 anos de idade (28%) foram mais afetadas. Esta alta prevalência de doença evitável pela vacinação é inaceitável, portanto, vacinação deste grupo de alto risco de HBV deve ser considerada fundamental

    Efficient error correction and haplotypes reconstruction for deep sequencing of hepatitis c amplicons

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    Секция 1. Защита информации и компьютерный анализ данныхWe present two new highly efficient pyrosequencing error correction algorithms: (i) k-mer – based error correction (KEC); and (ii) empirical frequency threshold (ET). Both were compared to the recently published clustering algorithm SHORAH to evaluate the relative performance using 24 experimental datasets obtained by 454-sequencing of amplicons with known sequences. We found that all three algorithms showed similar performance in terms of finding true haplotypes, but KEC and ET methods significantly outperformed SHORAH both in terms of their ability to remove false haplotypes and to estimate the frequency of true ones

    Broad Antibody Mediated Cross-Neutralization and Preclinical Immunogenicity of New Codon-Optimized HIV-1 Clade CRF02_AG and G Primary Isolates

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    Creation of an effective vaccine for HIV has been an elusive goal of the scientific community for almost 30 years. Neutralizing antibodies are assumed to be pivotal to the success of a prophylactic vaccine but previous attempts to make an immunogen capable of generating neutralizing antibodies to primary “street strain” isolates have resulted in responses of very limited breadth and potency. The objective of the study was to determine the breadth and strength of neutralizing antibodies against autologous and heterologous primary isolates in a cohort of HIV-1 infected Nigerians and to characterize envelopes from subjects with particularly broad or strong immune responses for possible use as vaccine candidates in regions predominated by HIV-1 CRF02_AG and G subtypes. Envelope vectors from a panel of primary Nigerian isolates were constructed and tested with plasma/sera from the same cohort using the PhenoSense HIV neutralizing antibody assay (Monogram Biosciences Inc, USA) to assess the breadth and potency of neutralizing antibodies. The immediate goal of this study was realized by the recognition of three broadly cross-neutralizing sera: (NG2-clade CRF02_AG, NG3-clade CRF02_AG and NG9- clade G). Based on these findings, envelope gp140 sequences from NG2 and NG9, complemented with a gag sequence (Clade G) and consensus tat (CRF02_AG and G) antigens have been codon-optimized, synthesized, cloned and evaluated in BALB/c mice. The intramuscular administration of these plasmid DNA constructs, followed by two booster DNA immunizations, induced substantial specific humoral response against all constructs and strong cellular responses against the gag and tat constructs. These preclinical findings provide a framework for the design of candidate vaccine for use in regions where the HIV-1 epidemic is driven by clades CRF02_AG and G

    Evaluation of Intra-Host Variants of the Entire Hepatitis B Virus Genome

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    Genetic analysis of hepatitis B virus (HBV) frequently involves study of intra-host variants, identification of which is commonly achieved using short regions of the HBV genome. However, the use of short sequences significantly limits evaluation of genetic relatedness among HBV strains. Although analysis of HBV complete genomes using genetic cloning has been developed, its application is highly labor intensive and practiced only infrequently. We describe here a novel approach to whole genome (WG) HBV quasispecies analysis based on end-point, limiting-dilution real-time PCR (EPLD-PCR) for amplification of single HBV genome variants, and their subsequent sequencing. EPLD-PCR was used to analyze WG quasispecies from serum samples of patients (n = 38) infected with HBV genotypes A, B, C, D, E and G. Phylogenetic analysis of the EPLD-isolated HBV-WG quasispecies showed the presence of mixed genotypes, recombinant variants and sub-populations of the virus. A critical observation was that HBV-WG consensus sequences obtained by direct sequencing of PCR fragments without EPLD are genetically close, but not always identical to the major HBV variants in the intra-host population, thus indicating that consensus sequences should be judiciously used in genetic analysis. Sequence-based studies of HBV WG quasispecies should afford a more accurate assessment of HBV evolution in various clinical and epidemiological settings

    Destructive fishing : an expert‐driven definition and exploration of this quasi‐concept

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    Numerous policy and international frameworks consider that “destructive fishing” hampers efforts to reach sustainability goals. Though ubiquitous, “destructive fishing” is undefined and therefore currently immeasurable. Here we propose a definition developed through expert consultation: “Destructive fishing is any fishing practice that causes irrecoverable habitat degradation, or which causes significant adverse environmental impacts, results in long-term declines in target or nontarget species beyond biologically safe limits and has negative livelihood impacts.” We show strong stakeholder support for a definition, consensus on many biological and ecological dimensions, and no clustering of respondents from different sectors. Our consensus definition is a significant step toward defining sustainable fisheries goals and will help interpret and implement global political commitments which utilize the term “destructive fishing.” Our definition and results will help reinforce the Food and Agricultural Organization's Code of Conduct and meaningfully support member countries to prohibit destructive fishing practices

    Urban-Rural estimation of hepatitis c virus infection sero-prevalence in North Central Nigeria

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    Background/Objective: The epidemiology of hepatitis C virus (HCV) infection has been partially described for at risk groups in urban communities in Nigeria. On the other hand, literature on the possible spread of the virus in rural Nigeria remains extremely scanty. The objective of this study was to estimate the prevalence of HCV in a rural and urban community in Nigeria.Methods: Four hundred and twenty four (n=424) plasma samples belonging to 238 rural inhabitants and 186 urban dwellers in North Central Nigeria were tested for anti-HCV markers using a third generation quantitative enzyme-linked immunosorbent assay (ELISA) that uses recombinant proteins and synthetic peptides derived from core and non-structural regions.Results: 29(12.2%, CI=0.17-0.86) of the rural samples and 5(2.7%, CI=0.01-0.06) of urban samples were positive for HCV infection. The highest number of infections was in the 21-40 years age category. Our preliminary findings indicates that the number of HCV infection in rural was higher (p=0.03) when compared with urban settings in Nigeria.Conclusion: Our results suggest a higher prevalence of HCV infection in rural than urban Nigeria in the region studied and possibly in Nigeria as a whole. HCV transmission is active in rural Nigeria and large scale studies to understand the dynamics of the infection are required so as to plan targeted preventive measures

    Serological markers and risk factors for Hepatitis B and Hepatitis C viruses among students in a Nigerian university

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    Objective: The aim of this cross-sectional study was to estimate the seroprevalence rates of hepatitis B virus and hepatitis C virus infections and to analyze associated risk factors among 400 students in a Nigerian. Methods: Participants were interviewed in a faceto-face sessions through a short structured questionnaire. Qualitative rapid immuno-chromatography test were used to screen for HBsAg and anti-HCV antibodies and these were confirmed by using third generation quantitative enzyme-linked immunosorbent assay (ELISAs).Results: Seroprevalence rates were: HBV. All these individuals were asymptomatic and unaware of their hepatitis status prior to thisstudy. We did not detect any case of HBV/HCV co-infection. The risk of being infected with HBV or HCV was not associated with marital status or having facial/tribal (p>0.05). A significant association was found between HCV (not HBV) infection and blood transfusion {OR=5.0(95%CI=0.91-27.47); ÷2=4.15; p=0.04}.Conclusion: Although the seroprevalence of HBV and HCV is lower among university students when compared to blood donors, HIV/AIDS patients and health workers in Nigeria. We have shown that these viruses circulate among the study population and blood transfusion identified as the factors most associated with HCV infection. Routine donor screening needs to be enforced and it is essential to implement prevention strategies focused on university students and youths in general
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