A5077809855- Viral Infections and Vectors
- Viral Infections and Outbreaks Research
- Mosquito-borne diseases and control
- Viral gastroenteritis research and epidemiology
- Animal Virus Infections Studies
- Hepatitis B Virus Studies
- SARS-CoV-2 and COVID-19 Research
- Disaster Response and Management
- Virology and Viral Diseases
- Zoonotic diseases and public health
- Malaria Research and Control
- Immune Cell Function and Interaction
- Plant Virus Research Studies
- Vector-borne infectious diseases
- Viral Infections and Immunology Research
- HIV Research and Treatment
- Vector-Borne Animal Diseases
- Virus-based gene therapy research
- Hepatitis Viruses Studies and Epidemiology
- Herpesvirus Infections and Treatments
- COVID-19 epidemiological studies
- Respiratory viral infections research
- Rabies epidemiology and control
- Animal Disease Management and Epidemiology
- Primate Behavior and Ecology
Institut de Recherche pour le Développement
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Maladies Infectieuses et Vecteurs: Écologie, Génétique, Évolution et Contrôle
2016-2025
Université de Montpellier
2012-2025
Inserm
2025
Agropolis International
2011-2024
Recherches Translationnelles sur le VIH et les Maladies Infectieuses
2024
Centre International de Recherches Médicales de Franceville
2012-2023
Administración Nacional de Laboratorios e Institutos de Salud
2022
Laboratoire National de Santé Publique du Congo
2022
In T cell-deficient conditions, naive cells undergo spontaneous "homeostatic" proliferation in response to contact with self-MHC/peptide ligands. With the aid of an vitro system, we show here that homeostatic is also cytokine-dependent. The cytokines IL-4, IL-7, and IL-15 enhanced vitro. Of these cytokines, only IL-7 was found be critical; thus, underwent IL-4(-) IL-15(-) hosts but proliferated minimally IL-7(-) hosts. addition proliferation, prolonged survival requires IL-7. Thus, naïve...
The overall size and composition of the pool naive memory T cells are tightly regulated by homeostatic mechanisms. Recent work has shown that homeostasis is controlled two factors, self-major histocompatibility complex (MHC)/peptide ligands a cytokine, interleukin (IL)-7. In particular, contact with these factors required for CD4+ CD8+ to undergo “homeostatic” proliferation, i.e., proliferation induced as consequence severe cell depletion. contrast cells, drive poorly understood. To address...
Several human and animal Ebola outbreaks have occurred over the past 4 years in Gabon Republic of Congo. The consisted multiple simultaneous epidemics caused by different viral strains, each epidemic resulted from handling a distinct gorilla, chimpanzee, or duiker carcass. These populations declined markedly during outbreaks, apparently as result infection. Recovered carcasses were infected variety suggesting that great apes virus introductions natural host. Surveillance mortality may help...
Background Chikungunya and dengue viruses emerged in Gabon 2007, with large outbreaks primarily affecting the capital Libreville several northern towns. Both subsequently spread to south-east of country, new occurring 2010. The mosquito species Aedes albopictus, that was known as a secondary vector for both viruses, recently invaded country primary involved Gabonese outbreaks. We conducted retrospective study human sera mosquitoes collected from 2007 2010, order identify other circulating...
The large virus family Paramyxoviridae includes some of the most significant human and livestock viruses, such as measles-, distemper-, mumps-, parainfluenza-, Newcastle disease-, respiratory syncytial metapneumoviruses. Here we identify an estimated 66 new paramyxoviruses in a worldwide sample 119 bat rodent species (9,278 individuals). Major discoveries include evidence origin Hendra- Nipah Africa, identification conspecific with mumps virus, detection close relatives mouse pneumonia-...
Twelve years after the Kikwit Ebola outbreak in 1995, virus reemerged Occidental Kasaï province of Democratic Republic Congo (DRC) between May and November 2007, affecting more than 260 humans causing 186 deaths. During this latter we conducted several epidemiological investigations to identify underlying ecological conditions animal sources. Qualitative social environmental data were collected through interviews with villagers by direct observation. The local populations reported no unusual...
Unbiased next-generation sequencing (NGS) approaches enable comprehensive pathogen detection in the clinical microbiology laboratory and have numerous applications for public health surveillance, outbreak investigation, diagnosis of infectious diseases. However, practical deployment technology is hindered by bioinformatics challenge analyzing results accurately a clinically relevant timeframe. Here we describe SURPI (“sequence-based ultrarapid identification”), computational pipeline...
Marburg and Ebola viruses can cause large hemorrhagic fever (HF) outbreaks with high case fatality (80–90%) in human great apes. Identification of the natural reservoir these is one most important topics this field a fundamental key to understanding their history. Despite discovery virus family almost 40 years ago, search for lethal pathogens remains an enigma despite numerous ecological studies. Here, we report common species fruit bat (Rousettus aegyptiacus) Gabon as shown by finding...
Ebolavirus species Zaire (ZEBOV) causes highly lethal hemorrhagic fever, resulting in the death of 90% patients within days. Most information on immune responses to ZEBOV comes from vitro studies and animal models. The paucity data human this virus is mainly due fact that most outbreaks occur remote areas. Published setting, based small numbers samples limited panels immunological markers, have given somewhat different results.Here, we studied a unique collection 56 blood 42 nonsurvivors 14...
The seventh reported outbreak of Ebola virus disease (EVD) in the equatorial African country Democratic Republic Congo (DRC) began on July 26, 2014, as another large EVD epidemic continued to spread West Africa. Simultaneous reports and Africa raised question whether two outbreaks were linked.We obtained data from patients DRC, using standard World Health Organization clinical-investigation form for viral hemorrhagic fevers. Patients classified having suspected, probable, or confirmed a...
Since 2004, several million indigenous cases of Chikungunya virus disease occurred in Africa, the Indian Ocean, India, Asia and, recently, Europe. The virus, usually transmitted by Aedes aegypti mosquitoes, has now repeatedly been associated with a new vector, Ae. Albopictus. Analysis full-length viral sequences reveals three independent events exposure to Albopictus, each followed acquisition single adaptive mutation providing selective advantage for transmission this mosquito. This...
Ebola and Marburg viruses cause highly lethal hemorrhagic fevers in humans. Recently, bats of multiple species have been identified as possible natural hosts Zaire ebolavirus (ZEBOV) Gabon Republic Congo, also marburgvirus (MARV) Democratic Congo. We tested 2147 belonging to at least nine sampled between 2003 2008 three regions the epidemic region north Congo for IgG antibodies specific ZEBOV MARV. Overall, MARV were found 4% 1% bats, respectively. ZEBOV-specific six bat (Epomops franqueti,...
Since its discovery in Nigeria 1991, Aedes albopictus has invaded much of Central Africa, a region where Ae. aegypti also occurs. To assess the relationship between invasion by and recent emergence dengue virus (DENV) chikungunya (CHIKV), we undertook vector competence experiments on populations collected from Cameroon conducted field investigations during concurrent epidemics DENV CHIKV Gabon. Overall, infection dissemination rates were not significantly different when exposed to titers...
ABSTRACT Hepatitis E virus (HEV) is one of the most common causes acute hepatitis in tropical and temperate climates. Tropical genotypes 1 2 are associated with food-borne waterborne transmission. Zoonotic reservoirs (mainly pigs, wild boar, deer) considered for 3 4, which exist In view association several zoonotic viruses bats, we analyzed 3,869 bat specimens from 85 different species five continents hepevirus RNA. HEVs were detected African, Central American, European forming a novel...
ABSTRACT We previously showed that close relatives of human coronavirus 229E (HCoV-229E) exist in African bats. The small sample and limited genomic characterizations have prevented further analyses so far. Here, we tested 2,087 fecal specimens from 11 bat species sampled Ghana for HCoV-229E-related viruses by reverse transcription-PCR (RT-PCR). Only hipposiderid bats positive. To compare the genetic diversity HCoV-229E, historical isolates diagnostic globally over 10 years. Bat were 5-...
Chikungunya virus (CHIKV) is a worldwide emerging pathogen. In humans it causes syndrome characterized by high fever, polyarthritis, and in some cases lethal encephalitis. Growing evidence indicates that the innate immune response plays role controlling CHIKV infection. We show here induces major but transient modifications NK-cell phenotype function soon after onset of acute report clonal expansion NK cells coexpress CD94/NKG2C inhibitory receptors for HLA-C1 alleles are correlated with...
Infection with the new coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), termed coronavirus infectious disease 19 (COVID-19), came to attention of health workers in December 2019 when a cluster people who attended seafood and animal market Wuhan, Hubei Province, China presented severe respiratory illness [1,2]. The outbreak, first localized quickly spread neighbouring provinces within three months was declared pandemic, cases reported nearly 200 countries all regions...
In a survey of household cats and dogs laboratory-confirmed COVID-19 patients, we found high seroprevalence SARS-CoV-2 antibodies, ranging from 21% to 53%, depending on the positivity criteria chosen. Seropositivity was significantly greater among pets COVID-19+ households compared those with owners unknown status. Our results highlight potential role in spread epidemic.