Zaire Ebolavirus

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Michael Hawkes - One of the best experts on this subject based on the ideXlab platform.

  • prior vaccination with recombinant vesicular stomatitis virus Zaire Ebolavirus vaccine is associated with improved survival among patients with Ebolavirus infection
    Vaccine, 2020
    Co-Authors: Masumbuko Claude Kasereka, Austin Ericson, Andrea L. Conroy, Lukaba Tumba, Ombeni Didier Mwesha, Michael Hawkes
    Abstract:

    Abstract The second largest Ebolavirus disease (EVD) outbreak ever recorded is currently ongoing in Eastern Democratic Republic of the Congo (DRC). This is the first outbreak for which the recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus (rVSV-ZEBOV) candidate vaccine has been widely administered, using a ring vaccination strategy. We examined whether prior vaccination with rVSV-ZEBOV impacts viral load, organ impairment, and survival among patients with EVD admitted to Ebola Treatment Units (ETUs) in the DRC. We conducted a retrospective observational study of patients admitted to the ETUs in Butembo and Katwa, Eastern DRC, between 30 March and 10 August 2019. We included 257 patients, of whom 44 had been vaccinated prior to admission and 213 were unvaccinated. Vaccinated patients were admitted to hospital sooner than unvaccinated patients (median 2 days (IQR 1.8–4) versus 4 days (IQR 3–6), p

  • Prior vaccination with recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus vaccine is associated with improved survival among patients with Ebolavirus infection
    Vaccine, 2020
    Co-Authors: Masumbuko Claude Kasereka, Austin Ericson, Andrea L. Conroy, Lukaba Tumba, Ombeni Didier Mwesha, Michael Hawkes
    Abstract:

    Abstract The second largest Ebolavirus disease (EVD) outbreak ever recorded is currently ongoing in Eastern Democratic Republic of the Congo (DRC). This is the first outbreak for which the recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus (rVSV-ZEBOV) candidate vaccine has been widely administered, using a ring vaccination strategy. We examined whether prior vaccination with rVSV-ZEBOV impacts viral load, organ impairment, and survival among patients with EVD admitted to Ebola Treatment Units (ETUs) in the DRC. We conducted a retrospective observational study of patients admitted to the ETUs in Butembo and Katwa, Eastern DRC, between 30 March and 10 August 2019. We included 257 patients, of whom 44 had been vaccinated prior to admission and 213 were unvaccinated. Vaccinated patients were admitted to hospital sooner than unvaccinated patients (median 2 days (IQR 1.8–4) versus 4 days (IQR 3–6), p

  • ebola epidemic in war torn democratic republic of congo 2018 acceptability and patient satisfaction of the recombinant vesicular stomatitis virus Zaire Ebolavirus vaccine
    Vaccine, 2019
    Co-Authors: Masumbuko Claude Kasereka, Julia Sawatzky, Michael Hawkes
    Abstract:

    Abstract Background The current Ebola outbreak in Eastern Democratic Republic of the Congo (DRC) is the second largest in history and the first in which the recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus (rVSV-ZEBOV) vaccine has been used at scale. We assessed side-effects, satisfaction, and attitudes toward the new vaccine. Methods Cross-sectional survey questionnaire from a convenience sample of 90 vaccine recipients and 96 community controls in Eastern DRC. Results Side-effects were reported in 75/90 (83%) vaccine recipients but only 5 (7%) and 4 (5%) reported arthralgia and rash, respectively. 76/90 (84%) vaccinees were classified as “promoters” (would recommend vaccine to others) and 6/90 (7%) as “detractors.” 69/96 (72%) of unvaccinated community controls would wish to be vaccinated if supply were available. 153/186 (82%) would accept vaccination for family members. Conclusions The rVSV-ZEBOV vaccine was well tolerated, with high acceptability in the community during the current outbreak in the DRC.

Heinz Feldmann - One of the best experts on this subject based on the ideXlab platform.

  • Dendritic Cells Generated From Mops condylurus, a Likely Filovirus Reservoir Host, Are Susceptible to and Activated by Zaire Ebolavirus Infection.
    Frontiers in immunology, 2019
    Co-Authors: Kathryn M. Edenborough, Heinz Feldmann, Marcel Bokelmann, Angelika Lander, Emmanuel Couacy-hymann, Johanna Lechner, Oliver Drechsel, Bernhard Y. Renard, Aleksandar Radonić, Andreas Kurth
    Abstract:

    Ebola virus infection of human dendritic cells (DCs) induces atypical adaptive immune responses and thereby exacerbates Ebola virus disease (EVD). Human DCs, infected with Ebola virus aberrantly express low levels of the DC activation markers CD80, CD86, and MHC class II. The T cell responses ensuing are commonly anergic rather than protective against EVD. We hypothesize that DCs derived from potential reservoir hosts such as bats, which do not develop disease signs in response to Ebola virus infection, would exhibit features associated with activation. In this study, we have examined Zaire Ebolavirus (EBOV) infection of DCs derived from the Angolan free-tailed bat species, Mops condylurus. This species was previously identified as permissive to EBOV infection in vivo, in the absence of disease signs. M. condylurus has also been recently implicated as the reservoir host for Bombali Ebolavirus, a virus species that is closely related to EBOV. Due to the absence of pre-existing M. condylurus species-specific reagents, we characterized its de novo assembled transcriptome and defined its phylogenetic similarity to other mammals, which enabled the identification of cross-reactive reagents for M. condylurus bone marrow-derived DC (bat-BMDC) differentiation and immune cell phenotyping. Our results reveal that bat-BMDCs are susceptible to EBOV infection as determined by detection of EBOV specific viral RNA (vRNA). vRNA increased significantly 72 h after EBOV-infection and was detected in both cells and in culture supernatants. Bat-BMDC infection was further confirmed by the observation of GFP expression in DC cultures infected with a recombinant GFP-EBOV. Bat-BMDCs upregulated CD80 and chemokine ligand 3 (CCL3) transcripts in response to EBOV infection, which positively correlated with the expression levels of EBOV vRNA. In contrast to the aberrant responses to EBOV infection that are typical for human-DC, our findings from bat-BMDCs provide evidence for an immunological basis of asymptomatic EBOV infection outcomes.

  • Tip Your Cap for Ebola Virus Neutralization.
    Immunity, 2018
    Co-Authors: Sonja M. Best, Heinz Feldmann
    Abstract:

    Outbreaks of Ebola virus disease are caused by multiple virus species although current therapeutic monoclonal antibodies (mAb) are essentially limited to treating one species, Zaire Ebolavirus. In this issue of Immunity, Gilchuk et al. (2018) identify new mAbs with potent cross-neutralizing activity against three Ebolavirus species pathogenic to humans.

  • With Improved Cross-Protective Efficacy
    2016
    Co-Authors: Vesicular Stomatitis, Hideki Ebihara, Andrea Marzi, Allison Groseth, Virus–based Ebola Vaccines, Julie Callison, Kinola J. Williams, Thomas A W. Geisbert, Heinz Feldmann
    Abstract:

    newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)–based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig–adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and-VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response. In the preceding 3 decades, 4 different Ebola virus (EBOV) species have been identified: Zaire Ebolavirus (ZEBOV), Sudan Ebolavirus (SEBOV), Côte d’Ivoire ebo

  • Complete genome sequences of three ebola virus isolates from the 2014 outbreak in west Africa.
    Genome announcements, 2014
    Co-Authors: Thomas Hoenen, Stephan Gunther, Hideki Ebihara, Andrea Marzi, Friederike Feldmann, Gary P. Kobinger, Allison Groseth, Heinz Feldmann
    Abstract:

    ABSTRACT Here, we report the complete genome sequences, including the genome termini, of three Ebola virus isolates (species Zaire Ebolavirus) originating from Guinea that are now being widely used in laboratories in North America for research regarding West African Ebola viruses.

  • Host Response Dynamics Following Lethal Infection of Rhesus Macaques With Zaire Ebolavirus
    The Journal of Infectious Diseases, 2011
    Co-Authors: Hideki Ebihara, Barry Rockx, Andrea Marzi, Friederike Feldmann, Elaine Haddock, Douglas Brining, Rachel Lacasse, Don Gardner, Heinz Feldmann
    Abstract:

    To gain further insight into the interdependent pathogenic processes in Ebola hemorrhagic fever (EHF), we have examined the dynamics of host responses in individual rhesus macaques infected with Zaire Ebolavirus over the entire disease course. Examination of coagulation parameters revealed that decreased coagulation inhibitor activity triggered severe coagulopathy as indicated by prolonged coagulation times and decreased fibrinogen levels. This has been proposed as one of the significant mechanisms underlying disseminated intravascular coagulation in EHF patients. Furthermore, monitoring of expression levels for cytokines/chemokines suggested a mixed anti-inflammatory response syndrome (MARS), which indicates that a catastrophic uncontrolled immunological status contributes to the development of fatal hemorrhagic fever. These results highlight the pathological analogies between EHF and severe sepsis and not only contribute to our understanding of the pathogenic process, but will also help to establish novel postexposure treatment modalities.

Pierre E. Rollin - One of the best experts on this subject based on the ideXlab platform.

  • Reduced virus replication, proinflammatory cytokine production, and delayed macrophage cell death in human PBMCs infected with the newly discovered Bundibugyo Ebolavirus relative to Zaire Ebolavirus
    Virology, 2010
    Co-Authors: Manisha Gupta, Cynthia S. Goldsmith, Maureen G. Metcalfe, Christina F. Spipopoulou, Pierre E. Rollin
    Abstract:

    Bundibugyo Ebolavirus is a newly identified Ebolavirus species. The virus was responsible for a recent hemorrhagic fever outbreak in Uganda with an approximate 30% case fatality rate. In this study, we compared the pathogenesis of Bundibugyo with highly lethal Zaire Ebolavirus by using in vitro human PBMCs. We found that PBMCs infected with Bundibugyo Ebolaviruses resulted in 1 to 2 log lower virus yields compared to Zaire Ebolavirus and produced 2- to 10-fold lower levels of TNF-alpha, MCP-1, IL-1beta, MIP1-alpha and IL-10 than PBMCs infected with Zaire Ebolavirus. In addition, flow cytometric studies have shown lower levels and delay of the macrophage cell death in Bundibugyo Ebolavirus compared to Zaire Ebolavirus infection. The findings of slower Bundibugyo Ebolavirus replication, lower production of proinflammatory cytokines and delay in macrophage cell death provide insight into the basis of the lower case fatality observed with Bundibugyo Ebolavirus.

  • Large serological survey showing cocirculation of Ebola and Marburg viruses in Gabonese bat populations, and a high seroprevalence of both viruses in Rousettus aegyptiacus
    BMC Infectious Diseases, 2009
    Co-Authors: Xavier Pourrut, Jonathan S Towner, Stuart T. Nichol, Jean-paul Gonzalez, Marc Souris, Pierre E. Rollin, Eric M. Leroy
    Abstract:

    Background Ebola and Marburg viruses cause highly lethal hemorrhagic fevers in humans. Recently, bats of multiple species have been identified as possible natural hosts of Zaire Ebolavirus (ZEBOV) in Gabon and Republic of Congo, and also of marburgvirus (MARV) in Gabon and Democratic Republic of Congo.

  • Spatial and Temporal Patterns of Zaire Ebolavirus Antibody Prevalence in the Possible Reservoir Bat Species
    The Journal of Infectious Diseases, 2007
    Co-Authors: Xavier Pourrut, Jean-paul Gonzalez, Pierre E. Rollin, André Délicat, Thomas G. Ksiazek, Eric M. Leroy
    Abstract:

    To characterize the distribution of Zaire Ebolavirus (ZEBOV) infection within the 3 bat species (Epomops franqueti, Hypsignathus monstrosus, and Myonycteris torquata) that are possible reservoirs, we collected 1390 bats during 2003-2006 in Gabon and the Republic of the Congo. Detection of ZEBOV immunoglobulin G (IgG) in 40 specimens supports the role of these bat species as the ZEBOV reservoirs. ZEBOV IgG prevalence rates (5%) were homogeneous across epidemic and nonepidemic regions during outbreaks, indicating that infected bats may well be present in nonepidemic regions of central Africa. ZEBOV IgG prevalence decreased, significantly, to 1% after the outbreaks, suggesting that the percentage of IgG-positive bats is associated with virus transmission to other animal species and outbreak appearance. The large number of ZEBOV IgG-positive adult bats and pregnant H. monstrosus females suggests virus transmission within bat populations through fighting and sexual contact. Our study, thus, helps to describe Ebola virus circulation in bats and offers some insight into the appearance of outbreaks.

  • Secreted glycoprotein from Live Zaire Ebolavirus-infected cultures: preparation, structural and biophysical characterization, and thermodynamic stability.
    The Journal of infectious diseases, 2007
    Co-Authors: Laura G Barrientos, Amy M Martin, Robert M Wohlhueter, Pierre E. Rollin
    Abstract:

    Milligram quantities of Zaire Ebolavirus nonstructural, secreted glycoprotein (sGP) were purified to homogeneity, and this preparation was characterized by an array of biophysical and biochemical experiments. Mass-spectrometry analysis revealed sGP posttranslational modifications and regions susceptible to limited proteolysis. In solution, sGP has an absolute molar mass of 103 kDa, is monodisperse, and folds into a predominantly beta -sheet conformation with a distinct tertiary structure. sGP appears to have a unique free-energy landscape that facilitates reversible folding and a strong propensity for disulfide-linked dimeric quaternary structure under a wide range of conditions; the low apparent free energy of conformation transition of sGP ( Delta G=1.7+/-0.1 kcal/mol) suggests that the molecule is well suited as a thermodynamically facile switch, which would allow it to report on relatively subtle changes in milieu. In addition, a conformational transition at 37 degrees C was detected in thermal denaturing experiments. On the basis of biophysical and biochemical considerations alone, we propose that the property of being a thermodynamically facile switch is an important clue to reveal sGP functionality.

  • Secreted Glycoprotein from Live Zaire Ebolavirus—Infected Cultures: Preparation, Structural and Biophysical Characterization, and Thermodynamic Stability
    The Journal of Infectious Diseases, 2007
    Co-Authors: Laura G Barrientos, Robert M Wohlhueter, Amy Martin, Pierre E. Rollin
    Abstract:

    Milligram quantities of Zaire Ebolavirus nonstructural, secreted glycoprotein (sGP) were purified to homogeneity, and this preparation was characterized by an array of biophysical and biochemical experiments. Mass-spectrometry analysis revealed sGP posttranslational modifications and regions susceptible to limited proteolysis. In solution, sGP has an absolute molar mass of 103 kDa, is monodisperse, and folds into a predominantly /3-sheet conformation with a distinct tertiary structure. sGP appears to have a unique free-energy landscape that facilitates reversible folding and a strong propensity for disulfide-linked dimeric quaternary structure under a wide range of conditions; the low apparent free energy of conformation transition of sGP (AG = 1.7 ± 0.1 kcal/mol) suggests that the molecule is well suited as a thermodynamically facile switch, which would allow it to report on relatively subtle changes in milieu. In addition, a conformational transition at 37°C was detected in thermal denaturing experiments. On the basis of biophysical and biochemical considerations alone, we propose that the property of being a thermodynamically facile switch is an important clue to reveal sGP functionality.

Masumbuko Claude Kasereka - One of the best experts on this subject based on the ideXlab platform.

  • prior vaccination with recombinant vesicular stomatitis virus Zaire Ebolavirus vaccine is associated with improved survival among patients with Ebolavirus infection
    Vaccine, 2020
    Co-Authors: Masumbuko Claude Kasereka, Austin Ericson, Andrea L. Conroy, Lukaba Tumba, Ombeni Didier Mwesha, Michael Hawkes
    Abstract:

    Abstract The second largest Ebolavirus disease (EVD) outbreak ever recorded is currently ongoing in Eastern Democratic Republic of the Congo (DRC). This is the first outbreak for which the recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus (rVSV-ZEBOV) candidate vaccine has been widely administered, using a ring vaccination strategy. We examined whether prior vaccination with rVSV-ZEBOV impacts viral load, organ impairment, and survival among patients with EVD admitted to Ebola Treatment Units (ETUs) in the DRC. We conducted a retrospective observational study of patients admitted to the ETUs in Butembo and Katwa, Eastern DRC, between 30 March and 10 August 2019. We included 257 patients, of whom 44 had been vaccinated prior to admission and 213 were unvaccinated. Vaccinated patients were admitted to hospital sooner than unvaccinated patients (median 2 days (IQR 1.8–4) versus 4 days (IQR 3–6), p

  • Prior vaccination with recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus vaccine is associated with improved survival among patients with Ebolavirus infection
    Vaccine, 2020
    Co-Authors: Masumbuko Claude Kasereka, Austin Ericson, Andrea L. Conroy, Lukaba Tumba, Ombeni Didier Mwesha, Michael Hawkes
    Abstract:

    Abstract The second largest Ebolavirus disease (EVD) outbreak ever recorded is currently ongoing in Eastern Democratic Republic of the Congo (DRC). This is the first outbreak for which the recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus (rVSV-ZEBOV) candidate vaccine has been widely administered, using a ring vaccination strategy. We examined whether prior vaccination with rVSV-ZEBOV impacts viral load, organ impairment, and survival among patients with EVD admitted to Ebola Treatment Units (ETUs) in the DRC. We conducted a retrospective observational study of patients admitted to the ETUs in Butembo and Katwa, Eastern DRC, between 30 March and 10 August 2019. We included 257 patients, of whom 44 had been vaccinated prior to admission and 213 were unvaccinated. Vaccinated patients were admitted to hospital sooner than unvaccinated patients (median 2 days (IQR 1.8–4) versus 4 days (IQR 3–6), p

  • ebola epidemic in war torn democratic republic of congo 2018 acceptability and patient satisfaction of the recombinant vesicular stomatitis virus Zaire Ebolavirus vaccine
    Vaccine, 2019
    Co-Authors: Masumbuko Claude Kasereka, Julia Sawatzky, Michael Hawkes
    Abstract:

    Abstract Background The current Ebola outbreak in Eastern Democratic Republic of the Congo (DRC) is the second largest in history and the first in which the recombinant Vesicular Stomatitis Virus – Zaire Ebolavirus (rVSV-ZEBOV) vaccine has been used at scale. We assessed side-effects, satisfaction, and attitudes toward the new vaccine. Methods Cross-sectional survey questionnaire from a convenience sample of 90 vaccine recipients and 96 community controls in Eastern DRC. Results Side-effects were reported in 75/90 (83%) vaccine recipients but only 5 (7%) and 4 (5%) reported arthralgia and rash, respectively. 76/90 (84%) vaccinees were classified as “promoters” (would recommend vaccine to others) and 6/90 (7%) as “detractors.” 69/96 (72%) of unvaccinated community controls would wish to be vaccinated if supply were available. 153/186 (82%) would accept vaccination for family members. Conclusions The rVSV-ZEBOV vaccine was well tolerated, with high acceptability in the community during the current outbreak in the DRC.

Eric M. Leroy - One of the best experts on this subject based on the ideXlab platform.

  • Large serological survey showing cocirculation of Ebola and Marburg viruses in Gabonese bat populations, and a high seroprevalence of both viruses in Rousettus aegyptiacus
    BMC Infectious Diseases, 2009
    Co-Authors: Xavier Pourrut, Jonathan S Towner, Stuart T. Nichol, Jean-paul Gonzalez, Marc Souris, Pierre E. Rollin, Eric M. Leroy
    Abstract:

    Background Ebola and Marburg viruses cause highly lethal hemorrhagic fevers in humans. Recently, bats of multiple species have been identified as possible natural hosts of Zaire Ebolavirus (ZEBOV) in Gabon and Republic of Congo, and also of marburgvirus (MARV) in Gabon and Democratic Republic of Congo.

  • Immunoglobulin G in Ebola Outbreak Survivors, Gabon
    Emerging infectious diseases, 2009
    Co-Authors: Nadia Wauquier, Pierre Becquart, Clélia Gasquet, Eric M. Leroy
    Abstract:

    To the Editor: Three well-documented outbreaks of Ebola hemorrhagic fever occurred from 1996 through 2001 in Gabon in central Africa (1). All were caused by the highly pathogenic species Zaire Ebolavirus, which is associated with an ≈80% case-fatality rate. The first outbreak hit Mayibout, a village in northeast Gabon in January and February 1996, causing 31 cases and 21 deaths. The first victims were children who helped carry and butcher a chimpanzee carcass found in the forest. The second outbreak lasted from October 1996 through March 1997 and occurred in the Booue region, about 150 km southwest of Mayibout, Gabon. The outbreak area was located along a trunk road and railroad track, and the infection spread to several villages around Booue, then to Libreville, the capital of Gabon, where 15 cases were recorded. The third outbreak occurred October 2001 through May 2002 in the Mekambo area, about 150 km from Mayibout in the east (2). This outbreak consisted of several independent chains of human transmission arising from infected animal carcasses, mainly chimpanzees and gorillas. It caused 65 cases and 53 deaths and coincided with major outbreaks in great apes that decimated wild populations (3,4). A total of 207 human cases were recorded during these 3 outbreaks; 149 persons died. Of the fatal and nonfatal cases 31 and 24, respectively, were confirmed by real-time reverse transcription–PCR, antigen detection, and immunoglobulin (Ig) G ELISA at Centre International de Recherches Medicales de Franceville (CIRMF) in Gabon. Because of the lack of available samples from survivors, little is known about the duration of IgG antibody response. However, studies of 20 survivors convalescing after the 1995 Kikwit outbreak in the Democratic Republic of the Congo (DRC) showed that Zaire Ebolavirus IgG appeared 5 to 18 days after symptom onset and persisted at least 21 months (5,6). With the exception of 2 survivors sampled 10 years after the 1976 Yambuku outbreak in DRC (7), no data are available on Zaire Ebolavirus IgG persistence beyond 21 months. Low seroprevalence rates of Ebola virus or Marburg virus found in surveys of patients in outbreak areas have been attributed to seroreversion (8–10). To investigate the persistence of Zaire Ebolavirus IgG, we studied laboratory-confirmed survivors of the 3 outbreaks in Gabon. The study was approved by the Gabon Ministry of Health and by the traditional chief of each village, and written informed consent was obtained from each survivor. During 3 months of investigations in the different outbreak areas beginning in June 2007, we located 11, 3, and 6 survivors of the 2001 Mekambo, 1996 Booue, and 1996 Mayibout outbreaks, respectively. During home visits, the survivors underwent a brief medical consultation, malaria smears were taken, and basic medicines were provided to the villagers. We collected blood samples in EDTA tubes; plasma was separated by centrifugation in the field and stored in dry nitrogen until transfer to the CIRMF laboratory in Gabon, where it was stored at –80°C. ELISA was performed as previously described, using reagents provided by the Special Pathogens Branch, Centers for Disease Control and Prevention (Atlanta, GA, USA) (7). The optical density (OD) cut-off value (0.13) was calculated as the mean + 3 SD of adjusted OD values for 103 negative control serum samples obtained from Caucasian persons living in Europe. All 20 survivors had positive test results for Zaire Ebolavirus IgG (Table). The adjusted OD values at a dilution of 1:1,600 ranged from 0.3 to 3.4 in the 9 survivors of the 1996 outbreaks and from 0.7 to 3.5 in the 11 survivors of the 2001 outbreak. Adjusted OD values determined during the symptomatic period and/or a few days to 1 month after recovery were available for some survivors (Table). Specific IgG appeared by day 5 after symptom onset, increased during the symptomatic period (as shown by higher titers on day 10), peaked by day 30 (2 weeks after recovery), then declined slowly over several years. Zaire Ebolavirus IgG remained detectable, often at high levels, >11 years after the infection. Table Adjusted OD values in patients infected with Zaire Ebolavirus during 3 outbreaks in Gabon, determined by testing at days 5, 10, and/or 30 after symptom onset and again in 2007 (7 or 11 years after recovery)* These long-lasting IgG antibody responses found in 20 survivors of 3 different Zaire Ebolavirus outbreaks rule out the hypothesis that low Ebola virus (and Marburg virus) seroprevalence rates found in epidemic regions of Africa are due to rapid loss of specific IgG. Whether this immunity is sufficient to protect from recurrent infection remains undetermined. These findings show that IgG ELISA is suitable for epidemiologic and epizootiologic investigations of Ebola and that Zaire Ebolavirus IgG is an excellent indicator of Zaire Ebolavirus circulation in humans.

  • Spatial and Temporal Patterns of Zaire Ebolavirus Antibody Prevalence in the Possible Reservoir Bat Species
    The Journal of Infectious Diseases, 2007
    Co-Authors: Xavier Pourrut, Jean-paul Gonzalez, Pierre E. Rollin, André Délicat, Thomas G. Ksiazek, Eric M. Leroy
    Abstract:

    To characterize the distribution of Zaire Ebolavirus (ZEBOV) infection within the 3 bat species (Epomops franqueti, Hypsignathus monstrosus, and Myonycteris torquata) that are possible reservoirs, we collected 1390 bats during 2003-2006 in Gabon and the Republic of the Congo. Detection of ZEBOV immunoglobulin G (IgG) in 40 specimens supports the role of these bat species as the ZEBOV reservoirs. ZEBOV IgG prevalence rates (5%) were homogeneous across epidemic and nonepidemic regions during outbreaks, indicating that infected bats may well be present in nonepidemic regions of central Africa. ZEBOV IgG prevalence decreased, significantly, to 1% after the outbreaks, suggesting that the percentage of IgG-positive bats is associated with virus transmission to other animal species and outbreak appearance. The large number of ZEBOV IgG-positive adult bats and pregnant H. monstrosus females suggests virus transmission within bat populations through fighting and sexual contact. Our study, thus, helps to describe Ebola virus circulation in bats and offers some insight into the appearance of outbreaks.

  • Isolates of Zaire Ebolavirus from wild apes reveal genetic lineage and recombinants
    Proceedings of the National Academy of Sciences of the United States of America, 2007
    Co-Authors: Tatiana Wittmann, Roman Biek, Xavier Pourrut, Jean-paul Gonzalez, Alexandre Hassanin, Pierre Rouquet, Patricia Reed, Philippe Yaba, Leslie A. Real, Eric M. Leroy
    Abstract:

    Over the last 30 years, Zaire Ebolavirus (ZEBOV), a virus highly pathogenic for humans and wild apes, has emerged repeatedly in Central Africa. Thus far, only a few virus isolates have been characterized genetically, all belonging to a single genetic lineage and originating exclusively from infected human patients. Here, we describe the first ZEBOV sequences isolated from great ape carcasses in the Gabon/Congo region that belong to a previously unrecognized genetic lineage. According to our estimates, this lineage, which we also encountered in the two most recent human outbreaks in the Republic of the Congo in 2003 and 2005, diverged from the previously known viruses around the time of the first documented human outbreak in 1976. These results suggest that virus spillover from the reservoir has occurred more than once, as predicted by the multiple emergence hypothesis. However, the young age of both ZEBOV lineages and the spatial and temporal sequence of outbreaks remain at odds with the idea that the virus simply emerged from a long-established and widespread reservoir population. Based on data from two ZEBOV genes, we also demonstrate, within the family Filoviridae, recombination between the two lineages. According to our estimates, this event took place between 1996 and 2001 and gave rise to a group of recombinant viruses that were responsible for a series of outbreaks in 2001–2003. The potential for recombination adds an additional level of complexity to unraveling and potentially controlling the emergence of ZEBOV in humans and wildlife species.