The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Tanja Vollmer - One of the best experts on this subject based on the ideXlab platform.

  • Transfusion-Transmitted Hepatitis E: NAT Screening of Blood Donations and Infectious Dose.
    Frontiers in medicine, 2018
    Co-Authors: Jens Dreier, Cornelius Knabbe, Tanja Vollmer
    Abstract:

    The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The Infectious Dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than 2 years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the Infectious Dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/mL). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving an HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2-5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (

  • transfusion transmitted hepatitis e nat screening of blood donations and Infectious Dose
    Frontiers in Medicine, 2018
    Co-Authors: Jens Dreier, Cornelius Knabbe, Tanja Vollmer
    Abstract:

    The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The Infectious Dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than two years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the Infectious Dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/ml). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving a HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2-5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (<100 IU/ml). Of note, the distribution of viral RNA in blood components depends on the plasma content of the component; nonetheless, HEV RNA could be detected in RBCs even when low viral plasma loads of 100 to 1,000 IU/ml are present. Comprehensive retrospective studies of TT-HEV infection offered further insights into the infectivity of HEV RNA-positive blood products. Minipool HEV NAT screening (96 samples) of blood donations should be adequate as a routine screening assay to identify high viremic donors and will cover at least a large part of viremic phases.

J J H Chu - One of the best experts on this subject based on the ideXlab platform.

  • The mechanism of cell death during West Nile virus infection is dependent on initial Infectious Dose.
    Journal of General Virology, 2003
    Co-Authors: J J H Chu
    Abstract:

    The mechanism of West Nile (WN) virus-induced cell death is determined by the initial Infectious Dose. In Vero cells infected with WN virus at an m.o.i. of 10 or greater, morphological changes characteristic of necrosis were observed as early as 8 h post-infection (p.i.). Pathological changes included extensive cell swelling and loss of plasma membrane integrity, as revealed by optical and electron microscopy. High extracellular lactate dehydrogenase (LDH) activity was observed together with leakage of the high mobility group 1 (HMGB1) protein into the extracellular space. When cells undergo necrosis, they release the HMGB1 protein, a pro-inflammatory mediator cytokine. At high Infectious Doses, loss of cell plasma membrane integrity was due to the profuse budding of WN progeny virus particles during maturation. When this profuse budding process was disrupted using cytochalasin B, LDH activity was reduced dramatically. In contrast, WN virus-induced cell killing occurred predominantly by apoptosis when cells were infected with an m.o.i. of ⩽1; the process of apoptosis observed was much later after infection (32 h p.i.). Fragmentation of DNA, chromatin condensation and formation of apoptotic bodies were all observed. This WN virus-induced apoptosis pathway was initiated by the release of cytochrome c from the mitochondria and was accompanied by the formation of apoptosomes. In turn, this led to the activation of caspase-9 and –3, and to the cleavage of the poly(ADP-ribose) polymerase.

  • The mechanism of cell death during West Nile virus infection is dependent on initial Infectious Dose.
    The Journal of general virology, 2003
    Co-Authors: J J H Chu
    Abstract:

    The mechanism of West Nile (WN) virus-induced cell death is determined by the initial Infectious Dose. In Vero cells infected with WN virus at an m.o.i. of 10 or greater, morphological changes characteristic of necrosis were observed as early as 8 h post-infection (p.i.). Pathological changes included extensive cell swelling and loss of plasma membrane integrity, as revealed by optical and electron microscopy. High extracellular lactate dehydrogenase (LDH) activity was observed together with leakage of the high mobility group 1 (HMGB1) protein into the extracellular space. When cells undergo necrosis, they release the HMGB1 protein, a pro-inflammatory mediator cytokine. At high Infectious Doses, loss of cell plasma membrane integrity was due to the profuse budding of WN progeny virus particles during maturation. When this profuse budding process was disrupted using cytochalasin B, LDH activity was reduced dramatically. In contrast, WN virus-induced cell killing occurred predominantly by apoptosis when cells were infected with an m.o.i. of

Jens Dreier - One of the best experts on this subject based on the ideXlab platform.

  • Transfusion-Transmitted Hepatitis E: NAT Screening of Blood Donations and Infectious Dose.
    Frontiers in medicine, 2018
    Co-Authors: Jens Dreier, Cornelius Knabbe, Tanja Vollmer
    Abstract:

    The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The Infectious Dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than 2 years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the Infectious Dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/mL). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving an HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2-5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (

  • transfusion transmitted hepatitis e nat screening of blood donations and Infectious Dose
    Frontiers in Medicine, 2018
    Co-Authors: Jens Dreier, Cornelius Knabbe, Tanja Vollmer
    Abstract:

    The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The Infectious Dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than two years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the Infectious Dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/ml). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving a HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2-5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (<100 IU/ml). Of note, the distribution of viral RNA in blood components depends on the plasma content of the component; nonetheless, HEV RNA could be detected in RBCs even when low viral plasma loads of 100 to 1,000 IU/ml are present. Comprehensive retrospective studies of TT-HEV infection offered further insights into the infectivity of HEV RNA-positive blood products. Minipool HEV NAT screening (96 samples) of blood donations should be adequate as a routine screening assay to identify high viremic donors and will cover at least a large part of viremic phases.

Paul D R Johnson - One of the best experts on this subject based on the ideXlab platform.

  • Mycobacterium ulcerans low Infectious Dose and mechanical transmission support insect bites and puncturing injuries in the spread of Buruli ulcer
    PLoS neglected tropical diseases, 2017
    Co-Authors: John R. Wallace, Kirstie M. Mangas, Jessica L. Porter, Renee Marcsisin, Sacha J. Pidot, Brian O. Howden, Till F. Omansen, Weiguang Zeng, Jason K. Axford, Paul D R Johnson
    Abstract:

    Addressing the transmission enigma of the neglected disease Buruli ulcer (BU) is a World Health Organization priority. In Australia, we have observed an association between mosquitoes harboring the causative agent, Mycobacterium ulcerans, and BU. Here we tested a contaminated skin model of BU transmission by dipping the tails from healthy mice in cultures of the causative agent, Mycobacterium ulcerans. Tails were exposed to mosquito (Aedes notoscriptus and Aedes aegypti) blood feeding or punctured with sterile needles. Two of 12 of mice with M. ulcerans contaminated tails exposed to feeding A. notoscriptus mosquitoes developed BU. There were no mice exposed to A. aegypti that developed BU. Eighty-eight percent of mice (21/24) subjected to contaminated tail needle puncture developed BU. Mouse tails coated only in bacteria did not develop disease. A median incubation time of 12 weeks, consistent with data from human infections, was noted. We then specifically tested the M. ulcerans Infectious Dose-50 (ID50) in this contaminated skin surface infection model with needle puncture and observed an ID50 of 2.6 colony-forming units. We have uncovered a biologically plausible mechanical transmission mode of BU via natural or anthropogenic skin punctures.

  • Mycobacterium ulcerans low Infectious Dose and atypical mechanical transmission support insect bites and puncturing injuries in the spread of Buruli ulcer
    2016
    Co-Authors: John R. Wallace, Kirstie M. Mangas, Jessica L. Porter, Renee Marcsisin, Sacha J. Pidot, Brian O. Howden, Till F. Omansen, Weiguang Zeng, Jason K. Axford, Paul D R Johnson
    Abstract:

    Addressing the transmission enigma of the neglected disease Buruli ulcer (BU) is a World Health Organization priority. In Australia, we have been building a hierarchy of evidence implicating mosquitoes in transmission. Here we tested a contaminated skin model of BU transmission by dipping the tails from healthy mice in cultures of the causative agent, Mycobacterium ulcerans. Tails were exposed to mosquito blood feeding or punctured with sterile needles. Two of 11 of mice with M. ulcerans contaminated tails exposed to feeding mosquitoes developed BU. Eighteen of 20 mice subjected to contaminated tail needle puncture developed BU. Mouse tails coated only in bacteria did not develop disease. We observed a low Infectious Dose-50 of four colony-forming units and a median incubation time of 12 weeks, overlapping data from human infections. We have uncovered a highly efficient and biologically plausible atypical transmission mode of BU via natural or anthropogenic skin punctures.

Cornelius Knabbe - One of the best experts on this subject based on the ideXlab platform.

  • Transfusion-Transmitted Hepatitis E: NAT Screening of Blood Donations and Infectious Dose.
    Frontiers in medicine, 2018
    Co-Authors: Jens Dreier, Cornelius Knabbe, Tanja Vollmer
    Abstract:

    The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The Infectious Dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than 2 years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the Infectious Dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/mL). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving an HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2-5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (

  • transfusion transmitted hepatitis e nat screening of blood donations and Infectious Dose
    Frontiers in Medicine, 2018
    Co-Authors: Jens Dreier, Cornelius Knabbe, Tanja Vollmer
    Abstract:

    The risk and importance of transfusion-transmitted hepatitis E virus (TT-HEV) infections by contaminated blood products is currently a controversial discussed topic in transfusion medicine. The Infectious Dose, in particular, remains an unknown quantity. In the present study, we illuminate and review this aspect seen from the viewpoint of a blood donation service with more than two years of experience in routine HEV blood donor screening. We systematically review the actual status of presently known cases of TT-HEV infections and available routine NAT-screening assays. The review of the literature revealed a significant variation regarding the Infectious Dose causing hepatitis E. We also present the outcome of six cases confronted with HEV-contaminated blood products, identified by routine HEV RNA screening of minipools using the highly sensitive RealStar HEV RT-PCR Kit (95% LOD: 4.7 IU/ml). Finally, the distribution of viral RNA in different blood components [plasma, red blood cell concentrate (RBC), platelet concentrates (PC)] was quantified using the first WHO international standard for HEV RNA for NAT-based assays. None of the six patients receiving a HEV-contaminated blood product from five different donors (donor 1: RBC, donor 2-5: APC) developed an acute hepatitis E infection, most likely due to low viral load in donor plasma (<100 IU/ml). Of note, the distribution of viral RNA in blood components depends on the plasma content of the component; nonetheless, HEV RNA could be detected in RBCs even when low viral plasma loads of 100 to 1,000 IU/ml are present. Comprehensive retrospective studies of TT-HEV infection offered further insights into the infectivity of HEV RNA-positive blood products. Minipool HEV NAT screening (96 samples) of blood donations should be adequate as a routine screening assay to identify high viremic donors and will cover at least a large part of viremic phases.