Pierre Gallian

Aix-Marseille Université, Marsiglia, Provence-Alpes-Côte d'Azur, France

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Publications (72)236.37 Total impact

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    ABSTRACT: Ebola and Marburg viruses (family Filoviridae, genera Ebolavirus and Marburgvirus) cause haemorrhagic fevers in humans, often associated with high mortality rates. The presence of antibodies to Ebola virus (EBOV) and Marburg virus (MARV) has been reported in some African countries in individuals without a history of haemorrhagic fever. In this study, we present a MARV and EBOV seroprevalence study conducted amongst blood donors in the Republic of Congo and the analysis of risk factors for contact with EBOV. In 2011, we conducted a MARV and EBOV seroprevalence study amongst 809 blood donors recruited in rural (75; 9.3%) and urban (734; 90.7%) areas of the Republic of Congo. Serum titres of IgG antibodies to MARV and EBOV were assessed by indirect double-immunofluorescence microscopy. MARV seroprevalence was 0.5% (4 in 809) without any identified risk factors. Prevalence of IgG to EBOV was 2.5%, peaking at 4% in rural areas and in Pointe Noire. Independent risk factors identified by multivariate analysis were contact with bats and exposure to birds. This MARV and EBOV serological survey performed in the Republic of Congo identifies a probable role for environmental determinants of exposure to EBOV. It highlights the requirement for extending our understanding of the ecological and epidemiological risk of bats (previously identified as a potential ecological reservoir) and birds as vectors of EBOV to humans, and characterising the protection potentially afforded by EBOV-specific antibodies as detected in blood donors.
    PLoS Neglected Tropical Diseases 06/2015; 9(6):e0003833. DOI:10.1371/journal.pntd.0003833 · 4.49 Impact Factor
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    ABSTRACT: Chikungunya virus (CHIKV) is a mosquito-borne arthralgic alphavirus that has garnered international attention as an important emerging pathogen since 2005. More recently, it invaded the Caribbean islands and the western hemisphere. Intriguingly, the current CHIKV outbreak in the Caribbean is caused by the Asian CHIKV genotype, which differs from the La Réunion LR2006 OPY1 isolate belonging to the Indian Ocean lineage. Here, we adopted a systematic and comparative approach against LR2006 OPY1 to characterize the pathogenicity of the Caribbean CNR20235 isolate and consequential host immune responses in mice. Ex vivo infection using primary mouse-tail fibroblasts revealed weaker replication efficiency by CNR20235 isolate. In the CHIKV mouse model, CNR20235 infection induced an enervated joint pathology characterized by moderate edema and swelling, independent of mononuclear cell infiltration. Based on systemic cytokine analysis, localized immune-phenotyping and gene expression profiles in the popliteal lymph node and inflamed joints, two pathogenic phases were defined for CHIKV infection: early acute (2-3 dpi) and late acute (6-8 dpi). Reduced joint pathology during early acute phase of CNR20235 infection was associated with a weaker pro-inflammatory Th1 response and natural killer (NK) cells activity. The pathological role of NK cells was further demonstrated as depletion of NK cells reduced joint pathology in LR2006 OPY1. Taken together, this study provides evidence that the Caribbean CNR20235 isolate has an enfeebled replication and induces a less pathogenic response in the mammalian host. The introduction of CHIKV in the Americas has heightened the risk of large-scale outbreaks due to the close proximity between the United States and the Caribbean. Immune-pathogenicity of the circulating Caribbean CHIKV isolate was explored, where it was demonstrated to exhibit reduced infectivity resulting in a weakened joint pathology. Analysis of serum cytokine levels, localized immune-phenotyping, and gene expression profile in the organs revealed that a limited Th1 response and reduced NK cells activity could underlie the reduced pathology in the host. Interestingly, higher asymptomatic infections were observed in the Caribbean compared to the La Réunion outbreaks in 2005-2006. This is the first study that showed an association between key pro-inflammatory factors and pathology-mediating leukocytes with a less severe pathological outcome in Caribbean CHIKV infection. Given the limited information regarding the sequela of Caribbean CHIKV infection, our study is timely and will aid the understanding of this increasingly important disease. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
    Journal of Virology 05/2015; DOI:10.1128/JVI.00909-15 · 4.65 Impact Factor
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    ABSTRACT: We screened plasma samples (minipools of 96 samples, corresponding to 53,234 blood donations) from France that had been processed with solvent-detergent for hepatitis E virus RNA. The detection rate was 1 HEV-positive sample/2,218 blood donations. Most samples (22/24) from viremic donors were negative for IgG and IgM against HEV.
    Emerging infectious diseases 11/2014; 20(11):1914-7. DOI:10.3201/eid2011.140516 · 7.33 Impact Factor
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    ABSTRACT: Background The risk assessment for blood transfusion is an essential step that must precede any screening strategy of a pathogen transmitted by transfusion. After several cases of HEV transmission by transfusion in France, a risk assessment for this virus was performed. Methods We used a method based on the prevalence of HEV-RNA in plasmas collected for the preparation of SD-plasma. To estimate the rate of HEV-RNA positive among all blood donations, data on SD-plasma were adjusted on the following HEV risk factors: gender, age group and region of residence. We assumed that HEV risk factors were the same in plasma donors and whole blood donors. Results Among 57,101 plasma donations tested for HEV-RNA in 2013, 24 were positive (crude rate of 4.2 per 10,000 donations). After adjustment, the total number of HEV-RNA positive blood donations was estimated at 788, accounting for a rate of 2.65 per 10,000 donations (95% CI: 1.6–3.7) or 1 in 3800 donations (1 in 6,200–1 in 2,700). This rate was 12 times higher in men than in women, increased with age, and varied according to region of residence. Conclusion The risk of blood donation contamination by HEV has been estimated to be 1 in 3800 donations in 2013. An essential input is still missing to assess now the risk in recipients: the minimum infectious dose. Furthermore, the risk in recipients has to be analyzed according to characteristics of transfused patients: presence of anti-HEV immunity, existence of chronic liver disease or immunodeficiency.
    Transfusion Clinique et Biologique 11/2014; 21(4-5). DOI:10.1016/j.tracli.2014.07.004 · 0.67 Impact Factor
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    ABSTRACT: Hepatitis E virus (HEV) is a non-enveloped RNA virus transmitted by the fecal-oral route. Autochthonous hepatitis E occurring in developed countries is caused by genotypes 3 and 4 and is a zoonotic infection. Humans are infected mostly after ingestion of undercooked meat from infected animals. Most HEV 3 and 4 infections are clinically inapparent. However, genotype 3 (HEV 3) can lead to chronic hepatitis in immuno-compromised patients such as organ-transplant recipients and patients with haematological malignancies. In Europe, HEV 3 is implicated in transfusion-transmitted HEV infection. In France, as observed in several European countries, prevalence of HEV RNA and specific IgG antibodies are high indicating that viral circulation is important. The systematic HEV NAT screening of blood donations used for preparation of solvent detergent plasma indicate that 1 to 2218 donation is infected by HEV RNA. The need or implementation's impacts of safety measures to prevent HEV transmission by blood transfusion are under reflexion by French's health authorities. The HEV NAT screening is the only available tool of prevention. Alternative strategies are under investigation including individual or mini pool NAT testing all or part of blood donations.
    Transfusion Clinique et Biologique 11/2014; 21(4-5). DOI:10.1016/j.tracli.2014.07.007 · 0.67 Impact Factor
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    ABSTRACT: Hepatitis E virus (HEV) is a non-enveloped RNA virus transmitted by the fecal-oral route. Autochthonous hepatitis E occurring in developed countries is caused by genotypes 3 and 4 and is a zoonotic infection. Humans are infected mostly after ingestion of undercooked meat from infected animals. Most HEV 3 and 4 infections are clinically inapparent. However, genotype 3 (HEV 3) can lead to chronic hepatitis in immuno-compromised patients such as organ-transplant recipients and patients with haematological malignancies. In Europe, HEV 3 is implicated in transfusion-transmitted HEV infection. In France, as observed in several European countries, prevalence of HEV RNA and specific IgG antibodies are high indicating that viral circulation is important. The systematic HEV NAT screening of blood donations used for preparation of solvent detergent plasma indicate that 1 to 2218 donation is infected by HEV RNA. The need or implementation's impacts of safety measures to prevent HEV transmission by blood transfusion are under reflexion by French's health authorities. The HEV NAT screening is the only available tool of prevention. Alternative strategies are under investigation including individual or mini pool NAT testing all or part of blood donations.
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    ABSTRACT: The risk assessment for blood transfusion is an essential step that must precede any screening strategy of a pathogen transmitted by transfusion. After several cases of HEV transmission by transfusion in France, a risk assessment for this virus was performed.
  • Blood 06/2014; 123(23):3679-81. DOI:10.1182/blood-2014-03-564880 · 9.78 Impact Factor
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    ABSTRACT: Considering the worldwide dissemination of Aedes mosquitoes, several years ago some of us anticipated the globalization of Chikungunya through invasion of the Americas, and alerted that the question was not if it can happen but when it will happen [1]. Arboviruses present an ongoing challenge to medicine and public health. Chikungunya virus was first isolated in Africa in the 1950's at the border of Tanzania and Mozambique. This article is protected by copyright. All rights reserved.
    Clinical Microbiology and Infection 05/2014; 20(7). DOI:10.1111/1469-0691.12694 · 5.20 Impact Factor
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    ABSTRACT: In France, there are no consistent data estimating hepatitis delta virus (HDV) prevalence in the general population. To better characterize HDV/HBV infection and its trends over a 15-years period from 1997 to 2011, we used data retrieved from the National Epidemiological Donors database including viral and demographic characteristics of all French HBV infected blood donors. Of the 39,911,011 donations collected over the 15 year-study-period, 6214 (1.56 in 10(4) donations) were confirmed positive for HBV from which 72.3% were tested for HDV antibodies (Ab). HDV viral load was performed using a real-time PCR assay on positive HDV Ab samples and HDV genotype determined for each positive viremic sample. Among the 4492 HBV donations, 89 (1.98%) were HDV Ab positive. After being stable around 1.1% from 1997 to 2005, this rate has continuously increased to reach 6.5% in 2010, before declining to 0.85% in 2011. Of the 61 investigated HDV Ab positive individuals, 22.9% were viremic with a viral load ranging from 10(4) to 9.8×10(7)copiesmL(-1). Genotyping revealed 12 HDV-1, 1 HDV-6 and 1 HDV-7 in accordance with the geographical origin of individuals. Such a study gives unexpected features of HBV-HDV infection in the population of blood donors which is a priori, a healthy population. The increase of HDV prevalence mainly linked to migration of population from endemic countries, demonstrates that there is still no complete control of HBV infection and must encourage HBV vaccination campaigns and systematic screening for HDV in HBV-infected.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 12/2013; 59(2). DOI:10.1016/j.jcv.2013.11.016 · 3.47 Impact Factor
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    ABSTRACT: Emerging viral infections in humans are appearing at an increasing rate. Recently, we identified a new Marseillevirus, named Giant Blood Marseillevirus (GBM), by performing viral metagenomics on asymptomatic blood donors. To study and compare the prevalence of Marseillevirus between asymptomatic blood donors and thalassemia patients. Here, we present a combined molecular and serological study on 174 asymptomatic blood donors and 22 patients with thalassemia who receive repeated blood transfusions to estimate the prevalence of Marseillevirus in these two populations. We identified Marseillevirus genomic DNA in 4% of donors, whereas 9.1% of the thalassemia patients were positive for this virus. Moreover, IgG seropositivity was detected in 22.7% of patients in the thalassemia group, whereas this seropositivity was observed in 12.6% of the blood donor population. These results suggest that Marseillevirus infection is not rare in healthy persons and may be transmitted by transfusion, thus raising speculation regarding the long-term consequences of this viral infection, particularly in patients requiring repeated blood transfusions.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 10/2013; 58(4). DOI:10.1016/j.jcv.2013.10.001 · 3.47 Impact Factor
  • Transfusion Clinique et Biologique 06/2013; 20(3):279–280. DOI:10.1016/j.tracli.2013.04.094 · 0.67 Impact Factor
  • Transfusion Clinique et Biologique 06/2013; 20(3):267. DOI:10.1016/j.tracli.2013.04.053 · 0.67 Impact Factor
  • Transfusion Clinique et Biologique 06/2013; 20(3):353. DOI:10.1016/j.tracli.2013.03.220 · 0.67 Impact Factor
  • Transfusion Clinique et Biologique 06/2013; 20(3):262–263. DOI:10.1016/j.tracli.2013.04.040 · 0.67 Impact Factor
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    ABSTRACT: BACKGROUND AND OBJECTIVES: Blood incompatibility arises from individual and ethnic differences in red blood cell (RBC) antigen profiles. This underlines the importance of documenting RBC antigen variability in various ethnic groups. Central Asia is an area with a long and complex migratory history. The purpose of this article is to describe key antigen frequencies of Afghan ethnic groups in the Hindu-Kush region of Afghanistan as a basis for improving blood transfusion practices in that area. MATERIALS AND METHODS: The key ABO, Rh and Kell antigens were investigated in five Afghan populations. In order to depict accurately the blood group gene diversity in the area, DNA from eight additional Pakistani populations were included, and the entire sample set screened using two multiplex polymerase chain reactions sensitive for 17 alleles in 10 blood group genetic systems (MNS, Kell, Duffy, Kidd, Cartwright, Dombrock, Indian, Colton, Diego and Landsteiner-Wiener). RESULTS: Phenotype and allele frequencies fell within the ranges observed in Western European and East Asian populations. Occurrence of DI*01, IN*01, LW*07 and FY*02N.01 and prevalence of ABO*B were consistent with migratory history as well as with putative environmental adaptation in the subtropical environment Hindu-Kush region. CONCLUSION: These findings expand the current knowledge about key antigen frequencies. Regarding occurrence of viral markers, further blood transfusion in the region requires rigorous typing.
    Transfusion Medicine 04/2013; 23(3). DOI:10.1111/tme.12038 · 1.31 Impact Factor
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    Emerging Infectious Diseases 05/2011; 17(5):941-3. DOI:10.3201/eid1705.101052 · 7.33 Impact Factor
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    ABSTRACT: Abstract To the Editor: Toscana virus (TOSV) is an arthropod-borne RNA virus (family Bunyaviridae and genus Phlebovirus) transmitted by sandflies in Mediterranean countries. TOSV causes acute meningitis and meningoencephalitis in patients. In France, cases of TOSV infections involving resident populations and cases imported by tourists traveling in TOSV-endemic countries have been reported (1,2); the virus has also been isolated from local wild-caught sandflies (1). The fact that TOSV has been isolated from human blood on several occasions (2) suggests a potential risk exists for transmitting the virus through blood transfusion or organ transplantation. We investigated the presence of TOSV antibodies in a sample of the healthy population, blood donors from southeastern France. PMID:21529423[PubMed - in process] LinkOut - more resourcesFull Text SourcesEBSCO
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    ABSTRACT: To determine the prevalence of hepatitis E virus (HEV) infection among sheltered homeless persons in Marseille, France, we retrospectively tested 490 such persons. A total of 11.6% had immunoglobulin (Ig) G and 2.5% had IgM against HEV; 1 person had HEV genotype 3f. Injection drug use was associated with IgG against HEV.
    Emerging Infectious Diseases 11/2010; 16(11):1761-3. DOI:10.3201/eid1611.091890 · 7.33 Impact Factor
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    Clinical Microbiology and Infection 10/2010; 16(12):1702-4. DOI:10.1111/j.1469-0691.2010.03386.x · 5.20 Impact Factor

Publication Stats

2k Citations
236.37 Total Impact Points

Institutions

  • 2010–2015
    • Aix-Marseille Université
      Marsiglia, Provence-Alpes-Côte d'Azur, France
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France
  • 2014
    • Ecole des hautes études en santé publique
      Roazhon, Brittany, France
  • 2001–2014
    • Etablissement Français du Sang (EFS)
      Lutetia Parisorum, Île-de-France, France
  • 2008–2009
    • ESC Bretagne Brest
      Brest, Brittany, France
  • 2003
    • Institute of Research for Development
      Marsiglia, Provence-Alpes-Côte d'Azur, France