LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 5 of total 5

Search options

  1. Article: Genetic Diversity of Hepatitis B and C Viruses Revealed by Continuous Surveillance from 2015 to 2021 in Gabon, Central Africa.

    Abe, Haruka / Ushijima, Yuri / Bikangui, Rodrigue / Ondo, Georgelin Nguema / Pemba, Christelle M / Zadeh, Vahid R / Mpingabo, Patrick I / Ueda, Hayato / Agnandji, Selidji T / Lell, Bertrand / Yasuda, Jiro

    Microorganisms

    2023  Volume 11, Issue 8

    Abstract: Viral hepatitis remains one of the largest public health concerns worldwide. Especially in Central Africa, information on hepatitis virus infections has been limited, although the prevalence in this region has been reported to be higher than the global ... ...

    Abstract Viral hepatitis remains one of the largest public health concerns worldwide. Especially in Central Africa, information on hepatitis virus infections has been limited, although the prevalence in this region has been reported to be higher than the global average. To reveal the current status of hepatitis B and C virus (HBV and HCV) infections and the genetic diversity of the viruses, we conducted longitudinal surveillance in Gabon. We detected 22 HBV and 9 HCV infections in 2047 patients with febrile illness. Genetic analyses of HBV identified subgenotype A1 for the first time in Gabon and an insertion generating a frameshift to create an X-preC/C fusion protein. We also revealed that most of the detected HCVs belonged to the "Gabon-specific" HCV subtype 4e (HCV-4e), and the entire nucleotide sequence of the HCV-4e polyprotein was determined to establish the first reference sequence. The HCV-4e strains possessed resistance-associated substitutions similar to those of other HCV-4 strains, indicating that the use of direct-acting antiviral therapy may be complex. These results provide a better understanding of the current situation of hepatitis B and C virus infections in Central Africa and will help public health organizations develop effective countermeasures to eliminate chronic viral hepatitis in this region.
    Language English
    Publishing date 2023-08-09
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2720891-6
    ISSN 2076-2607
    ISSN 2076-2607
    DOI 10.3390/microorganisms11082046
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: First evidence for continuous circulation of hepatitis A virus subgenotype IIA in Central Africa.

    Abe, Haruka / Ushijima, Yuri / Bikangui, Rodrigue / Ondo, Georgelin N / Zadeh, Vahid R / Pemba, Christelle M / Mpingabo, Patrick I / Igasaki, Yui / de Vries, Sophia G / Grobusch, Martin P / Loembe, Marguerite M / Agnandji, Selidji T / Lell, Bertrand / Yasuda, Jiro

    Journal of viral hepatitis

    2020  Volume 27, Issue 11, Page(s) 1234–1242

    Abstract: Although a high seroprevalence of antibodies against hepatitis A virus (HAV) has been estimated in Central Africa, the current status of both HAV infections and seroprevalence of anti-HAV antibodies remains unclear due to a paucity of surveillance data ... ...

    Abstract Although a high seroprevalence of antibodies against hepatitis A virus (HAV) has been estimated in Central Africa, the current status of both HAV infections and seroprevalence of anti-HAV antibodies remains unclear due to a paucity of surveillance data available. We conducted a serological survey during 2015-2017 in Gabon, Central Africa, and confirmed a high seroprevalence of anti-HAV antibodies in all age groups. To identify the currently circulating HAV strains and to reveal the epidemiological and genetic characteristics of the virus, we conducted molecular surveillance in a total of 1007 patients presenting febrile illness. Through HAV detection and sequencing, we identified subgenotype IIA (HAV-IIA) infections in the country throughout the year. A significant prevalence trend emerged in the young child population, presenting several infection peaks which appeared to be unrelated to dry or rainy seasons. Whole-genome sequencing and phylogenetic analyses revealed local HAV-IIA evolutionary events in Central Africa, indicating the circulation of HAV-IIA strains of a region-specific lineage. Recombination analysis of complete genome sequences revealed potential recombination events in Gabonese HAV strains. Interestingly, Gabonese HAV-IIA possibly acquired the 5'-untranslated region (5'-UTR) of the rare subgenotype HAV-IIB in recent years, suggesting the present existence of HAV-IIB in Central Africa. These findings indicate a currently stable HAV-IIA circulation in Gabon, with a high risk of infections in children aged under 5 years. Our findings will enhance the understanding of the current status of HAV infections in Central Africa and provide new insight into the molecular epidemiology and evolution of HAV genotype II.
    MeSH term(s) Africa, Central ; Child ; Female ; Gabon ; Genotype ; Hepatitis A/immunology ; Hepatitis A Antibodies ; Hepatitis A virus/isolation & purification ; Humans ; Male ; Phylogeny ; Seroepidemiologic Studies
    Chemical Substances Hepatitis A Antibodies
    Language English
    Publishing date 2020-06-29
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1212497-7
    ISSN 1365-2893 ; 1352-0504
    ISSN (online) 1365-2893
    ISSN 1352-0504
    DOI 10.1111/jvh.13348
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 4119: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article ; Online: Re-emergence of dengue virus serotype 3 infections in Gabon in 2016-2017, and evidence for the risk of repeated dengue virus infections.

    Abe, Haruka / Ushijima, Yuri / Loembe, Marguerite M / Bikangui, Rodrigue / Nguema-Ondo, Georgelin / Mpingabo, Patrick I / Zadeh, Vahid R / Pemba, Christelle M / Kurosaki, Yohei / Igasaki, Yui / de Vries, Sophia G / Grobusch, Martin P / Agnandji, Selidji T / Lell, Bertrand / Yasuda, Jiro

    International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases

    2019  Volume 91, Page(s) 129–136

    Abstract: Objectives: Dengue outbreaks, mainly caused by dengue virus serotype 2 (DENV-2), occurred in 2007 and in 2010 in Gabon, Central Africa. However, information on DENV infections has been insufficient since 2010. The aim of this study was to investigate ... ...

    Abstract Objectives: Dengue outbreaks, mainly caused by dengue virus serotype 2 (DENV-2), occurred in 2007 and in 2010 in Gabon, Central Africa. However, information on DENV infections has been insufficient since 2010. The aim of this study was to investigate the current DENV infection scenario and the risk of repeated infections in Gabon.
    Methods: During 2015-2017, serum samples were collected from enrolled febrile participants and were tested for DENV infection using RT-qPCR. DENV-positive samples were analyzed for a history of previous DENV infection(s) using ELISA. The complete DENV genome was sequenced to analyze the phylogeny of Gabonese DENV strains.
    Results: DENV-3 was exclusively detected, with a high rate of anti-DENV IgG seropositivity among DENV-3-positive participants. DENV-3 showed higher infection rates in adults and the infection was seasonal with peaks in the rainy seasons. Phylogenetic analysis revealed that Gabonese DENV-3 originated from West African strains and has been circulating continuously in Gabon since at least 2010, when the first DENV-3 case was reported.
    Conclusions: These findings indicate stable DENV-3 circulation and the risk of repeated DENV infections in Gabon, highlighting the need for continuous monitoring to control DENV infections.
    MeSH term(s) Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Dengue/epidemiology ; Dengue/virology ; Dengue Virus/classification ; Dengue Virus/genetics ; Dengue Virus/isolation & purification ; Female ; Gabon/epidemiology ; Humans ; Infant ; Male ; Middle Aged ; Phylogeny ; Real-Time Polymerase Chain Reaction ; Seasons ; Seroepidemiologic Studies ; Serogroup ; Young Adult
    Language English
    Publishing date 2019-12-07
    Publishing country Canada
    Document type Journal Article
    ZDB-ID 1331197-9
    ISSN 1878-3511 ; 1201-9712
    ISSN (online) 1878-3511
    ISSN 1201-9712
    DOI 10.1016/j.ijid.2019.12.002
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 4516: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article: Development of an RT-LAMP assay for the detection of Lassa viruses in southeast and south-central Nigeria

    Pemba, Christelle M / Ajayi, Nnenna A / Chika-Igwenyi, Nneka M / Chukwubike, Chinedu M / Iroezindu, Michael O / Kurosaki, Yohei / Maehira, Yuki / Ndu, Anne C / Nwafor, Ifeanyi / Nwidi, Damian U / Ojide, Chiedozie K / Oloniniyi, Olamide K / Onwe, Emeka O / Sueyoshi, Maki / Unigwe, Uche S / Urata, Shuzo / Yasuda, Jiro / Yoshikawa, Rokusuke / Zadeh, Vahid R

    Journal of virological methods. 2019 July, v. 269

    2019  

    Abstract: Lassa virus (LASV) causes Lassa fever (LF), a viral hemorrhagic fever endemic in West Africa. LASV strains are clustered into six lineages according to their geographic location. To confirm a diagnosis of LF, a laboratory test is required. Here, a ... ...

    Abstract Lassa virus (LASV) causes Lassa fever (LF), a viral hemorrhagic fever endemic in West Africa. LASV strains are clustered into six lineages according to their geographic location. To confirm a diagnosis of LF, a laboratory test is required. Here, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay using a portable device for the detection of LASV in southeast and south-central Nigeria using three primer sets specific for strains clustered in lineage II was developed. The assay detected in vitro transcribed LASV RNAs within 23 min and was further evaluated for detection in 73 plasma collected from suspected LF patients admitted into two health settings in southern Nigeria. The clinical evaluation using the conventional RT-PCR as the reference test revealed a sensitivity of 50% in general with 100% for samples with a viral titer of 9500 genome equivalent copies (geq)/mL and higher. The detection limit was estimated to be 4214 geq/mL. The assay showed 98% specificity with no cross-reactivity to other viruses which cause similar symptoms. These results suggest that this RT-LAMP assay is a useful molecular diagnostic test for LF during the acute phase, contributing to early patient management, while using a convenient device for field deployment and in resource-poor settings.
    Keywords clinical examination ; cross reaction ; detection limit ; fever ; genome ; laboratory experimentation ; Lassa mammarenavirus ; Lassa virus fever ; oligodeoxyribonucleotides ; patients ; portable equipment ; reverse transcriptase polymerase chain reaction ; reverse transcription loop-mediated isothermal amplification ; RNA ; transcription (genetics) ; viral load ; viruses ; Nigeria
    Language English
    Dates of publication 2019-07
    Size p. 30-37.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 8013-5
    ISSN 1879-0984 ; 0166-0934
    ISSN (online) 1879-0984
    ISSN 0166-0934
    DOI 10.1016/j.jviromet.2019.04.010
    Database NAL-Catalogue (AGRICOLA)

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 1565: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article ; Online: Development of an RT-LAMP assay for the detection of Lassa viruses in southeast and south-central Nigeria.

    Pemba, Christelle M / Kurosaki, Yohei / Yoshikawa, Rokusuke / Oloniniyi, Olamide K / Urata, Shuzo / Sueyoshi, Maki / Zadeh, Vahid R / Nwafor, Ifeanyi / Iroezindu, Michael O / Ajayi, Nnenna A / Chukwubike, Chinedu M / Chika-Igwenyi, Nneka M / Ndu, Anne C / Nwidi, Damian U / Maehira, Yuki / Unigwe, Uche S / Ojide, Chiedozie K / Onwe, Emeka O / Yasuda, Jiro

    Journal of virological methods

    2019  Volume 269, Page(s) 30–37

    Abstract: Lassa virus (LASV) causes Lassa fever (LF), a viral hemorrhagic fever endemic in West Africa. LASV strains are clustered into six lineages according to their geographic location. To confirm a diagnosis of LF, a laboratory test is required. Here, a ... ...

    Abstract Lassa virus (LASV) causes Lassa fever (LF), a viral hemorrhagic fever endemic in West Africa. LASV strains are clustered into six lineages according to their geographic location. To confirm a diagnosis of LF, a laboratory test is required. Here, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay using a portable device for the detection of LASV in southeast and south-central Nigeria using three primer sets specific for strains clustered in lineage II was developed. The assay detected in vitro transcribed LASV RNAs within 23 min and was further evaluated for detection in 73 plasma collected from suspected LF patients admitted into two health settings in southern Nigeria. The clinical evaluation using the conventional RT-PCR as the reference test revealed a sensitivity of 50% in general with 100% for samples with a viral titer of 9500 genome equivalent copies (geq)/mL and higher. The detection limit was estimated to be 4214 geq/mL. The assay showed 98% specificity with no cross-reactivity to other viruses which cause similar symptoms. These results suggest that this RT-LAMP assay is a useful molecular diagnostic test for LF during the acute phase, contributing to early patient management, while using a convenient device for field deployment and in resource-poor settings.
    MeSH term(s) DNA Primers/genetics ; Genome, Viral ; Humans ; Lassa Fever/blood ; Lassa Fever/diagnosis ; Lassa virus/isolation & purification ; Limit of Detection ; Molecular Diagnostic Techniques/methods ; Nigeria ; Nucleic Acid Amplification Techniques/instrumentation ; Nucleic Acid Amplification Techniques/methods ; RNA, Viral/genetics ; Reverse Transcription ; Sensitivity and Specificity ; Temperature ; Viral Load
    Chemical Substances DNA Primers ; RNA, Viral
    Language English
    Publishing date 2019-04-08
    Publishing country Netherlands
    Document type Evaluation Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 8013-5
    ISSN 1879-0984 ; 0166-0934
    ISSN (online) 1879-0984
    ISSN 0166-0934
    DOI 10.1016/j.jviromet.2019.04.010
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 1565: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top