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1.
PLoS Negl Trop Dis ; 12(10): e0006833, 2018 10.
Article in English | MEDLINE | ID: mdl-30359373

ABSTRACT

HTLV-1 infection is considered as highly endemic in central Africa. Thirty years ago, a first epidemiological study was performed in Gabon, central Africa, and revealed that the prevalence varied from 5.0 to 10.5%. To evaluate current distribution of HTLVs in Gabon, 4.381 samples were collected from rural population living in 220 villages distributed within the 9 provinces of country. HTLVs prevalence was determined using two ELISA tests and positive results were confirmed by Western Blot. The overall HTLV-1 seroprevalence was of 7.3% among the rural Gabonese population; with 5.4% for men and 9.0% for women. Prevalence of HTLV-1 differed by province, ranging from 2.3% to 12.5% into the rain forest. Being a woman older than 51 years represented a high risk for HTLV-1 acquisition. Hospitalization, operation/surgery, transfusion and medical abortion or fever, arthritis and abdominal pain are also significant risk factors. In addition, 0.1% of samples were found as HTLV-2 positive, while 12.0% had an indeterminate HTLV serological pattern. HTLV-3 and HTLV-4 were not found. Phylogenetic analysis was performed on 87 samples and demonstrated that HTLV-1 present in Gabon belongs mostly to subtype B, however the rare subtype D was also found. Altogether, our results demonstrate that almost thirty years after the first epidemiological study prevention of HTLVs infection is still an issue in Gabon.


Subject(s)
HTLV-I Infections/epidemiology , HTLV-II Infections/epidemiology , Rural Population , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Antibodies, Viral/blood , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Gabon/epidemiology , Human T-lymphotropic virus 1/classification , Human T-lymphotropic virus 1/genetics , Human T-lymphotropic virus 1/immunology , Human T-lymphotropic virus 2/immunology , Humans , Male , Middle Aged , Molecular Epidemiology , Phylogeny , Risk Factors , Sequence Analysis, DNA , Seroepidemiologic Studies , Surveys and Questionnaires , Young Adult
2.
Intervirology ; 61(4): 174-184, 2018.
Article in English | MEDLINE | ID: mdl-30625488

ABSTRACT

Non-malarial febrile illness outbreaks were documented in 2007 and 2010 in Gabon. After investigation, these outbreaks were attributed to the chikungunya and dengue viruses (CHIKV and DENV). However, for more than half of the samples analyzed, the causative agent was not identified. Given the geographical and ecological position of Gabon, where there is a great animal and microbial diversity, the circulation of other emerging viruses was suspected in these samples lacking aetiology. A total of 436 undiagnosed samples, collected between 2007 and 2013, and originating from 14 urban, suburban, and rural Gabonese locations were selected. These samples were used for viral isolation on newborn mice and VERO cells. In samples with signs of viral replication, cell supernatants and brain suspensions were used to extract nucleic acids and perform real-time RT-PCR targeting specific arboviruses, i.e., CHIKV, DENV, yellow fever, Rift Valley fever, and West Nile and Zika viruses. Virus isolation was conclusive for 43 samples either on newborn mice or by cell culture. Virus identification by RT-PCR led to the identification of CHIKV in 37 isolates. A total of 18 complete genomes and 19 partial sequences containing the E2 and E1 genes of CHIKV were sequenced using next-generation sequencing technology or the Sanger method. Phylogenetic analysis of the complete genomes showed that all the sequences belong to the East Central South Africa lineage. Furthermore, we identified 2 distinct clusters. The first cluster was made up of sequences from the western part of Gabon, whereas the second cluster was made up of sequences from the southern regions, reflecting the way CHIKV spread across the country following its initial introduction in 2007. Similar results were obtained when analyzing the CHIKV genes of the E2 and E1 structural proteins. Moreover, study of the mutations found in the E2 and E1 structural proteins revealed the presence of several mutations that facilitate the adaptation to the Aedes albopictus mosquito, such as E2 I211T and E1 A226V, in all the Gabonese CHIKV strains. Finally, sequencing of 6 additional viral isolates failed to lead to any conclusive identification.


Subject(s)
Chikungunya Fever/epidemiology , Disease Outbreaks , Fever of Unknown Origin/diagnosis , Viruses/isolation & purification , Animals , Animals, Newborn , Chlorocebus aethiops , Gabon/epidemiology , High-Throughput Nucleotide Sequencing , Humans , Mice , Phylogeny , Real-Time Polymerase Chain Reaction , Vero Cells , Viruses/classification , Viruses/genetics
3.
PLoS One ; 11(3): e0149599, 2016.
Article in English | MEDLINE | ID: mdl-26959686

ABSTRACT

Invasive species alter ecosystems, threaten native and endangered species, and have negative economic impacts. Knowing where invading individuals are from and when they arrive to a new site can guide management. Here, we evaluated how well the stable hydrogen isotope composition (δ2H) records the recent origin and time since arrival of specimens of the invasive Japanese beetle (Popillia japonica Newman) captured near the Portland International Airport (Oregon, U.S.A.). The δ2H of Japanese beetle specimens collected from sites across the contiguous U.S.A. reflected the δ2H of local precipitation, a relationship similar to that documented for other organisms, and one confirming the utility of δ2H as a geographic fingerprint. Within weeks after experimental relocation to a new isotopic environment, the δ2H of beetles changed linearly with time, demonstrating the potential for δ2H to also mark the timing of arrival to a new location. We used a hierarchical Bayesian model to estimate the recent geographical origin and timing of arrival of each specimen based on its δ2H value. The geographic resolution was broad, with values consistent with multiple regions of origin in the eastern U.S.A., slightly favoring the southeastern U.S.A. as the more likely source. Beetles trapped from 2007-2010 had arrived 30 or more days prior to trapping, whereas the median time since arrival declined to 3-7 days for beetles trapped from 2012-2014. This reduction in the time between arrival and trapping at the Portland International Airport supports the efficacy of trapping and spraying to prevent establishment. More generally, our analysis shows how stable isotopes can serve as sentinels of biological invasions, verifying the efficacy of control measures, or, alternatively, indicating when those measures show signs of failure.


Subject(s)
Coleoptera/physiology , Hydrogen/metabolism , Introduced Species , Animals , Isotopes , Probability , Rain , Time Factors , United States
4.
PLoS Negl Trop Dis ; 10(3): e0004499, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26938618

ABSTRACT

BACKGROUND: Dengue virus (DENV) is the most prominent arbovirus worldwide, causing major epidemics in South-East Asia, South America and Africa. In 2010, a major DENV-2 outbreak occurred in Gabon with cases of patients co-infected with chikungunya virus (CHIKV). Although the innate immune response is thought to be of primordial importance in the development and outcome of arbovirus-associated pathologies, our knowledge of the role of natural killer (NK) cells during DENV-2 infection is in its infancy. METHODOLOGY: We performed the first extensive comparative longitudinal characterization of NK cells in patients infected by DENV-2, CHIKV or both viruses. Hierarchical clustering and principal component analyses were performed to discriminate between CHIKV and DENV-2 infected patients. PRINCIPAL FINDINGS: We observed that both activation and differentiation of NK cells are induced during the acute phase of infection by DENV-2 and CHIKV. Combinatorial analysis however, revealed that both arboviruses induced two different signatures of NK-cell responses, with CHIKV more associated with terminal differentiation, and DENV-2 with inhibitory KIRs. We show also that intracellular production of interferon-γ (IFN-γ) by NK cells is strongly stimulated in acute DENV-2 infection, compared to CHIKV. CONCLUSIONS/SIGNIFICANCE: Although specific differences were observed between CHIKV and DENV-2 infections, the significant remodeling of NK cell populations observed here suggests their potential roles in the control of both infections.


Subject(s)
Chikungunya Fever/complications , Chikungunya Fever/pathology , Dengue/complications , Dengue/pathology , Killer Cells, Natural/immunology , Adult , Coinfection/pathology , Female , Gabon , Humans , Longitudinal Studies , Male
5.
J Clin Virol ; 64: 144-52, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25453326

ABSTRACT

Chikungunya virus (CHIKV) is an alphavirus of the Togaviridae family that causes chronic and incapacitating arthralgia in human populations. Since its discovery in 1952, CHIKV was responsible for sporadic and infrequent outbreaks. However, since 2005, global Chikungunya outbreaks have occurred, inducing some fatalities and associated with severe and chronic morbidity. Chikungunya is thus considered as an important re-emerging public health problem in both tropical and temperate countries, where the distribution of the Aedes mosquito vectors continues to expand. This review highlights the most recent advances in our knowledge and understanding of the epidemiology, biology, treatment and vaccination strategies of CHIKV.


Subject(s)
Aedes/virology , Chikungunya Fever , Chikungunya virus/physiology , Neglected Diseases , Africa/epidemiology , Animals , Asia/epidemiology , Chikungunya Fever/diagnosis , Chikungunya Fever/epidemiology , Chikungunya Fever/immunology , Chikungunya Fever/therapy , Chikungunya virus/genetics , Chikungunya virus/pathogenicity , Communicable Diseases, Emerging , Disease Outbreaks , Global Health , Humans , Insect Vectors/virology , Neglected Diseases/diagnosis , Neglected Diseases/epidemiology , Neglected Diseases/immunology , Neglected Diseases/therapy , Vaccination , Viral Vaccines
6.
J Infect Dis ; 211(3): 361-5, 2015 Feb 01.
Article in English | MEDLINE | ID: mdl-25147276

ABSTRACT

Of 78 Gabonese individuals who had received bites from nonhuman primates (NHPs) while hunting, 7 were infected with human T lymphotropic virus (HTLV-1). Five had been bitten by gorillas and were infected with subtype B strains; however, a 12-year-old girl who was severely bitten by a Cercopithecus nictitans was infected with a subtype D strain that was closely related to the simian T lymphotropic virus (STLV-1) that infects this monkey species. Her mother was infected with a subtype B strain. These data confirm that hunters in Africa can be infected by HTLV-1 that is closely related to the strains circulating among local NHP game. Our findings strongly suggest that a severe bite represent a risk factor for STLV-1 acquisition.


Subject(s)
HTLV-I Infections/virology , Human T-lymphotropic virus 1/classification , Human T-lymphotropic virus 1/genetics , Primates/virology , Africa, Central , Animals , Cercopithecus/virology , Child , Female , Gabon , Gorilla gorilla/virology , Haplorhini/virology , Humans , Male , Middle Aged , Monkey Diseases/virology , Phylogeny
7.
PLoS Negl Trop Dis ; 8(2): e2681, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24516683

ABSTRACT

BACKGROUND: Chikungunya and dengue viruses emerged in Gabon in 2007, with large outbreaks primarily affecting the capital Libreville and several northern towns. Both viruses subsequently spread to the south-east of the country, with new outbreaks occurring in 2010. The mosquito species Aedes albopictus, that was known as a secondary vector for both viruses, recently invaded the country and was the primary vector involved in the Gabonese outbreaks. We conducted a retrospective study of human sera and mosquitoes collected in Gabon from 2007 to 2010, in order to identify other circulating arboviruses. METHODOLOGY/PRINCIPAL FINDINGS: Sample collections, including 4312 sera from patients presenting with painful febrile disease, and 4665 mosquitoes belonging to 9 species, split into 247 pools (including 137 pools of Aedes albopictus), were screened with molecular biology methods. Five human sera and two Aedes albopictus pools, all sampled in an urban setting during the 2007 outbreak, were positive for the flavivirus Zika (ZIKV). The ratio of Aedes albopictus pools positive for ZIKV was similar to that positive for dengue virus during the concomitant dengue outbreak suggesting similar mosquito infection rates and, presumably, underlying a human ZIKV outbreak. ZIKV sequences from the envelope and NS3 genes were amplified from a human serum sample. Phylogenetic analysis placed the Gabonese ZIKV at a basal position in the African lineage, pointing to ancestral genetic diversification and spread. CONCLUSIONS/SIGNIFICANCE: We provide the first direct evidence of human ZIKV infections in Gabon, and its first occurrence in the Asian tiger mosquito, Aedes albopictus. These data reveal an unusual natural life cycle for this virus, occurring in an urban environment, and potentially representing a new emerging threat due to this novel association with a highly invasive vector whose geographic range is still expanding across the globe.


Subject(s)
Aedes/virology , Communicable Diseases, Emerging/virology , Zika Virus Infection/virology , Zika Virus/isolation & purification , Animals , Gabon/epidemiology , Humans , Phylogeny , Retrospective Studies , Zika Virus/classification , Zika Virus/genetics , Zika Virus Infection/epidemiology
8.
PLoS One ; 8(10): e78030, 2013.
Article in English | MEDLINE | ID: mdl-24205075

ABSTRACT

Gabon, in Central Africa, was affected for the first time in 2007 and then in 2010 by simultaneous outbreaks of chikungunya and Dengue serotype 2 (DENV-2) viruses. Through the national surveillance of dengue-like syndromes between 2007 and 2010, we observed continuous circulation of DENV-2 in a southward movement. This rapid spread of DENV-2 was associated with the emergence of DENV-1 in 2007 and DENV-3 in 2010. Interestingly, we detected six DENV-2 infected patients with hemorrhagic signs during the second outbreak in 2010. Although these cases do not meet all standard WHO criteria for severe Dengue with hemorrhage (formerly DHF), this is the first report of several dengue fever cases associated with hemorrhagic signs during a simultaneous circulation of different DENV serotypes in Africa. Together, these findings suggest that DENV is becoming more widely established on this continent and that DHF will likely become a serious public-health problem in the near future.


Subject(s)
Dengue/epidemiology , Africa/epidemiology , Dengue Virus/genetics , Dengue Virus/pathogenicity , Humans , Phylogeny , Real-Time Polymerase Chain Reaction
9.
Virol J ; 9: 254, 2012 Oct 31.
Article in English | MEDLINE | ID: mdl-23114258

ABSTRACT

BACKGROUND: Hepatitis E virus (HEV), an enterically transmitted pathogen, is highly endemic in several African countries. Pregnant women are at particularly high risk for acute or severe hepatitis E. In Gabon, a central African country, the prevalence of antibodies to HEV among pregnant women is 14.1%. Recent studies have demonstrated unusual patterns of hepatitis E (chronic hepatitis, cirrhosis) among immunodeficient patients. FINDINGS: We investigated the prevalence of antibodies to HEV among pregnant women infected with HIV-1 or HTLV-1 in Gabon. Of 243 samples collected, 183 were positive for HIV-1 and 60 for HTLV-1; 16 women (6.6%) had IgG antibodies to HEV. The seroprevalence was higher among HIV-1-infected women (7.1%) than HTLV-1-infected women (5.0%). Moreover, the HIV-1 viral load was significantly increased (p ≤ 0.02) among women with past-HEV exposure (1.3E+05 vs 5.7E+04 copies per ml), whereas no difference was found in HTLV-1 proviral load (9.0E+01 vs 1.1E+03 copies per ml). CONCLUSIONS: These data provide evidence that HIV-1-infected women are at risk for acute or severe infection if they are exposed to HEV during pregnancy, with an increased viral load.


Subject(s)
HIV Infections/complications , Hepatitis Antibodies/blood , Hepatitis E virus/immunology , Hepatitis E/epidemiology , Pregnancy Complications, Infectious , Adult , Female , Gabon/epidemiology , HIV Infections/virology , HIV-1/isolation & purification , HTLV-I Infections/complications , HTLV-I Infections/virology , Human T-lymphotropic virus 1/isolation & purification , Humans , Pregnancy , Risk Assessment , Risk Factors , Seroepidemiologic Studies , Viral Load
10.
PLoS One ; 7(8): e42002, 2012.
Article in English | MEDLINE | ID: mdl-22870274

ABSTRACT

BACKGROUND: The epidemiological and molecular characteristics of hepatitis C virus (HCV) infection in the general population have been poorly investigated in Africa. The aim of this study was to determine the prevalence, genotype distribution and epidemic history of HCV in the Gabonese general population. METHODS/PRINCIPAL FINDINGS: A total of 4042 sera collected from adults in 220 villages in all nine administrative areas of the country were screened for antibodies to HCV. HCV NS5B region sequencing was performed for molecular characterization and population genetic analyses. Of 4042 tested sera, 455 (11.2%) were positive. The seroprevalence of HCV varied significantly by administrative area, with the highest rate in Ogooué-Lolo province (20.4%) and the lowest in Ogooué-Maritine province (3.7%). History of parenteral injections, past hospital admission and age over 55 years were independent risk factors for HCV infection (p<0.0001). Phylogenetic analyses showed that 91.9% of the strains were genotype 4 (HCV-4), 5.7% genotype 1 and 2.2% genotype 2. HCV-4 strains were highly heterogeneous, with more than eight subtypes; subtype 4e predominated (57.3%). Coalescence analyses indicated that subtype 4e was the oldest, with an estimated most recent common ancestor of 1702 [95% CI, 1418-1884]. The epidemic profile indicated that it spread exponentially during the first part of the 20th century, probably by iatrogenic transmission. CONCLUSIONS/SIGNIFICANCE: These results confirm the endemicity of HCV subtype 4e in Gabon and show that its spread is due to a cohort effect, with previous, possibly iatrogenic events. More extensive epidemiological studies are needed to better characterize the route of transmission and the dissemination of HCV in Gabon.


Subject(s)
Hepacivirus/genetics , Hepatitis C/genetics , Phylogeny , Viral Nonstructural Proteins/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Gabon/epidemiology , Hepacivirus/pathogenicity , Hepatitis C/epidemiology , Hepatitis C/transmission , Humans , Male , Middle Aged , Phylogeography , Risk Factors , Sequence Analysis, RNA
11.
Clin Infect Dis ; 55(6): e45-53, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22670036

ABSTRACT

BACKGROUND: Chikungunya virus (CHIKV) and Dengue virus serotype 2 (DENV-2) were recently introduced in central Africa, along with Aedes albopictus. Simultaneous outbreaks of CHIKV and DENV-2 have subsequently occurred, in Cameroon in 2006 and Gabon in 2007. METHODS: To study the spread of the 2 viruses, we conducted active surveillance of acute febrile syndromes throughout Gabon between 2007 and 2010. Diagnostic methods included quantitative real-time reverse-transcription polymerase chain reaction, and molecular characterization was based on partial envelope gene sequences. RESULTS: Between 2007 and 2010, 4287 acutely febrile patients were investigated for CHIKV and DENV-2 infections, of whom 1567 were CHIKV-positive, 376 DENV-2-positive, and 37 coinfected. We diagnosed 153 CHIKV and 11 DENV-2 cases in 2008, and 5 CHIKV and 9 DENV-2 cases in 2009. In 2010, CHIKV and DENV-2 caused a second large simultaneous outbreak. Among 2826 acutely febrile patients examined during this outbreak, 1112 were CHIKV-positive, 288 DENV-2-positive, and 28 coinfected. Mosquitoes were collected near the homes of coinfected patients, and 1 Aedes albopictus specimen was found to be positive for both CHIKV and DENV-2. CONCLUSIONS: These findings show the rapid dissemination of CHIKV and DENV-2 within a nonimmune population in a tropical African country, probably facilitated by the spread of Aedes albopictus. This has resulted in major simultaneous outbreaks with numerous coinfections in both human and mosquito.


Subject(s)
Aedes/virology , Alphavirus Infections/epidemiology , Chikungunya virus/isolation & purification , Coinfection , Dengue Virus/isolation & purification , Dengue/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Alphavirus Infections/virology , Animals , Chikungunya virus/classification , Chikungunya virus/genetics , Child , Child, Preschool , Dengue/virology , Dengue Virus/classification , Dengue Virus/genetics , Disease Outbreaks , Female , Gabon/epidemiology , Humans , Infant , Male , Middle Aged , Molecular Epidemiology , Molecular Sequence Data , Real-Time Polymerase Chain Reaction , Sequence Analysis, DNA , Viral Envelope Proteins/genetics , Young Adult
12.
BMC Infect Dis ; 12: 64, 2012 Mar 20.
Article in English | MEDLINE | ID: mdl-22433277

ABSTRACT

BACKGROUND: In Africa, the wide genetic diversity of HIV has resulted in emergence of new strains, rapid spread of this virus in sub-Saharan populations and therefore spread of the HIV epidemic throughout the continent. METHODS: To determine the prevalence of antibodies to HIV among a high-risk population in Gabon, 1098 and 2916 samples were collected from pregnant women in 2005 and 2008, respectively. HIV genotypes were evaluated in 107 HIV-1-positive samples to determine the circulating subtypes of strains and their resistance to antiretroviral drugs (ARVs). RESULTS: The seroprevalences were 6.3% in 2005 and 6.0% in 2008. The main subtype was recombinant CRF02_AG (46.7%), followed by the subtypes A (19.6%), G (10.3%), F (4.7%), H (1.9%) and D (0.9%) and the complex recombinants CRF06_cpx (1.9%) and CRF11_cpx (1.9%); 12.1% of subtypes could not be characterized. Analysis of ARVs resistance to the protease and reverse transcriptase coding regions showed mutations associated with extensive subtype polymorphism. In the present study, the HIV strains showed reduced susceptibility to ARVs (2.8%), particularly to protease inhibitors (1.9%) and nucleoside reverse transcriptase inhibitors (0.9%). CONCLUSIONS: The evolving genetic diversity of HIV calls for continuous monitoring of its molecular epidemiology in Gabon and in other central African countries.


Subject(s)
Anti-Retroviral Agents/pharmacology , Drug Resistance, Viral , Genetic Variation , HIV Infections/epidemiology , HIV Infections/virology , HIV-1/classification , Pregnancy Complications, Infectious/epidemiology , Adolescent , Adult , Female , Gabon/epidemiology , Genotype , HIV Antibodies/blood , HIV-1/drug effects , HIV-1/genetics , HIV-1/isolation & purification , Humans , Middle Aged , Molecular Epidemiology , Mutation, Missense , Pregnancy , Pregnancy Complications, Infectious/virology , Seroepidemiologic Studies , Young Adult
13.
PLoS Negl Trop Dis ; 6(2): e1517, 2012.
Article in English | MEDLINE | ID: mdl-22348166

ABSTRACT

BACKGROUND: Chikungunya virus (CHIKV) has caused multiple outbreaks in tropical and temperate areas worldwide, but the clinical and biological features of this disease are poorly described, particularly in Africa. We report a prospective study of clinical and biological features during an outbreak that occurred in Franceville, Gabon in 2010. METHODOLOGY/PRINCIPAL FINDINGS: We collected, in suspect cases (individuals presenting with at least one of the following symptoms or signs: fever, arthralgias, myalgias, headaches, rash, fatigue, nausea, vomiting, diarrhea, bleeding, or jaundice), blood samples, demographic and clinical characteristics and outcome. Hematological and biochemical tests, blood smears for malaria parasites and quantitative PCR for CHIKV then dengue virus were performed. CHIKV+ patients with concomitant malaria and/or dengue were excluded from the study. From May to July 2010, data on 270 laboratory-confirmed CHIK patients were recorded. Fever and arthralgias were reported by respectively 85% and 90% of patients, while myalgias, rash and hemorrhage were noted in 73%, 42% and 2% of patients. The patients were grouped into 4 clinical categories depending on the existence of fever and/or joint pain. On this basis, mixed forms accounted for 78.5% of cases, arthralgic forms 12.6%, febrile forms 6.7% and unusual forms (without fever and arthralgias) 2.2%. No cases of organ failure or death were reported. Elevated liver enzyme and creatinine levels, anemia and lymphocytopenia were the predominant biological abnormalities, and lymphocytopenia was more severe in patients with high viral loads (p = 0.01). CONCLUSIONS/SIGNIFICANCE: During CHIK epidemics, some patients may not have classical symptoms. The existence of unusual forms and the absence of severe forms of CHIK call for surveillance to detect any change in pathogenicity.


Subject(s)
Alphavirus Infections/epidemiology , Alphavirus Infections/pathology , Chikungunya virus/isolation & purification , Disease Outbreaks , Adolescent , Adult , Aged , Alphavirus Infections/virology , Chikungunya Fever , Chikungunya virus/pathogenicity , Child , Child, Preschool , Female , Gabon/epidemiology , Humans , Infant , Male , Middle Aged , Prospective Studies , Severity of Illness Index , Young Adult
14.
Infect Dis Rep ; 4(1): e5, 2012 Jan 02.
Article in English | MEDLINE | ID: mdl-24470935

ABSTRACT

Chikungunya (CHIKV) and Dengue (DENV) viruses, both arboviruses, have caused multiple outbreaks worldwide. Their clinical features are poorly described in Africa and there is no comparative study, although Chikungunya is considered as a dengue-like disease. We conducted a comparative study of clinical and biological data from CHIKV and DENV positive patients during the 2010 Gabonese outbreak. Patients consulting with general symptoms and having laboratory confirmation for CHIKV or DENV were included. Clinical and biological data were recorded. Statistical analyses were performed using Epi Info. A P value < 0.05 was considered significant. In all, 270 CHIKV+, 53 DENV+ and 20 co-infected patients were included in the study. Headaches, hemorrhage, leukopenia and lymphopenia were significantly (P respectively 0.01, 0.001, 0.02 and 0.001) more frequent in DENV+ patients than in CHIKV+. There was no additive effect of the two viruses.These clinical and hematological disorders are non specific and cannot assist for the differential diagnosis. These diseases are clinically indistinguishable, and need for laboratory confirmation.

15.
Vector Borne Zoonotic Dis ; 12(2): 167-9, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22141733

ABSTRACT

Chikungunya virus (CHIKV) recently caused major urban outbreaks in central African countries such as the Democratic Republic of Congo (DRC), Cameroon, and Gabon. In Gabon, the tiger mosquito Aedes albopictus was shown to be the main CHIKV vector during the 2007 outbreak. This invasive Asian species was first identified in Gabon in early 2007, and was thought to be restricted mainly to coastal provinces where urban epidemic CHIKV foci were recorded. Here we report a CHIKV outbreak in a small cluster of villages isolated in the deep forest of southern Gabon, in which A. albopictus was the main vector. This observation indicates concomitant geographic and ecological spread of CHIKV activity and A. albopictus in remote environments in central Africa, as well as an enhanced risk of propagation of epidemic arboviruses.


Subject(s)
Aedes/virology , Alphavirus Infections/epidemiology , Insect Vectors/virology , Alphavirus Infections/transmission , Animals , Chikungunya Fever , Chikungunya virus/isolation & purification , Disease Outbreaks , Female , Gabon/epidemiology , Humans , Interviews as Topic
16.
J Virol ; 86(2): 1255-60, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22072747

ABSTRACT

In order to characterize simian foamy retroviruses (SFVs) in wild-born nonhuman primates (NHPs) in Gabon and to investigate cross-species transmission to humans, we obtained 497 NHP samples, composed of 286 blood and 211 tissue (bush meat) samples. Anti-SFV antibodies were found in 31 of 286 plasma samples (10.5%). The integrase gene sequence was found in 38/497 samples, including both blood and tissue samples, with novel SFVs in several Cercopithecus species. Of the 78 humans, mostly hunters, who had been bitten or scratched by NHPs, 19 were SFV seropositive, with 15 cases confirmed by PCR. All but one were infected with ape SFV. We thus found novel SFV strains in NHPs in Gabon and high cross-species transmission of SFVs from gorilla bites.


Subject(s)
Primate Diseases/transmission , Retroviridae Infections/transmission , Retroviridae Infections/veterinary , Simian foamy virus/physiology , Adolescent , Adult , Animals , Antibodies, Viral/immunology , Cercopithecus , Child , Child, Preschool , Female , Gabon , Humans , Male , Molecular Sequence Data , Phylogeny , Primate Diseases/immunology , Primate Diseases/virology , Primates , Retroviridae Infections/immunology , Retroviridae Infections/virology , Rural Health , Simian foamy virus/classification , Simian foamy virus/immunology , Simian foamy virus/isolation & purification , Young Adult
17.
Retrovirology ; 7: 105, 2010 Dec 14.
Article in English | MEDLINE | ID: mdl-21156043

ABSTRACT

BACKGROUND: Each of the pathogenic human retroviruses (HIV-1/2 and HTLV-1) has a nonhuman primate counterpart, and the presence of these retroviruses in humans results from interspecies transmission. The passage of another simian retrovirus, simian foamy virus (SFV), from apes or monkeys to humans has been reported. Mandrillus sphinx, a monkey species living in central Africa, is naturally infected with SFV. We evaluated the natural history of the virus in a free-ranging colony of mandrills and investigated possible transmission of mandrill SFV to humans. RESULTS: We studied 84 semi-free-ranging captive mandrills at the Primate Centre of the Centre International de Recherches Médicales de Franceville (Gabon) and 15 wild mandrills caught in various areas of the country. The presence of SFV was also evaluated in 20 people who worked closely with mandrills and other nonhuman primates. SFV infection was determined by specific serological (Western blot) and molecular (nested PCR of the integrase region in the polymerase gene) assays. Seropositivity for SFV was found in 70/84 (83%) captive and 9/15 (60%) wild-caught mandrills and in 2/20 (10%) humans. The 425-bp SFV integrase fragment was detected in peripheral blood DNA from 53 captive and 8 wild-caught mandrills and in two personnel. Sequence and phylogenetic studies demonstrated the presence of two distinct strains of mandrill SFV, one clade including SFVs from mandrills living in the northern part of Gabon and the second consisting of SFV from animals living in the south. One man who had been bitten 10 years earlier by a mandrill and another bitten 22 years earlier by a macaque were found to be SFV infected, both at the Primate Centre. The second man had a sequence close to SFVmac sequences. Comparative sequence analysis of the virus from the first man and from the mandrill showed nearly identical sequences, indicating genetic stability of SFV over time. CONCLUSION: Our results show a high prevalence of SFV infection in a semi-free-ranging colony of mandrills, with the presence of two different strains. We also showed transmission of SFV from a mandrill and a macaque to humans.


Subject(s)
Mandrillus/virology , Monkey Diseases/virology , Occupational Diseases/virology , Occupational Exposure/adverse effects , Retroviridae Infections/transmission , Retroviridae Infections/veterinary , Simian foamy virus/physiology , Adult , Animal Technicians , Animals , Female , Humans , Male , Middle Aged , Molecular Sequence Data , Monkey Diseases/transmission , Phylogeny , Retroviridae Infections/virology , Simian foamy virus/classification , Simian foamy virus/genetics , Simian foamy virus/isolation & purification , Young Adult
18.
Virology ; 405(1): 225-33, 2010 Sep 15.
Article in English | MEDLINE | ID: mdl-20591460

ABSTRACT

In the absence of an effective vaccine against HIV, it is urgent to develop an effective alternative such as a microbicide. Single and repeated applications of MC1220 microbicide were evaluated in macaques. First, animals were given a single application of 0.5% or 1.5% MC1220-containing liposomal gel. A second group were treated with 0.5% MC1220 once a day for 4 days. The control groups were treated by liposomal gel alone. Thirty minutes after the last application, animals were challenged with RT-SHIV. In the first protocol, 2 of 4 animals treated by 0.5% of the MC1220 and 2 of 5 treated by 1.5% were protected. In the second protocol, 3 of 5 treated animals were protected and 5 of 5 controls were infected. The RNA viral load at necropsy was significantly lower (p=0.05) in treated-infected animals than in controls. In both protocols, the number of CD4+ T cells was lower at viremia peak in infected than in protected animals.


Subject(s)
HIV/drug effects , Pyrimidinones/therapeutic use , Reverse Transcriptase Inhibitors/therapeutic use , Simian Acquired Immunodeficiency Syndrome/prevention & control , Simian Immunodeficiency Virus/drug effects , Animals , Antibodies, Viral/blood , Female , Fluorobenzenes , Gels , HIV/genetics , Liposomes , Macaca mulatta , Pyrimidinones/adverse effects , Reassortant Viruses , Reverse Transcriptase Inhibitors/adverse effects , Simian Immunodeficiency Virus/genetics , Viral Load
19.
AIDS Res Hum Retroviruses ; 25(4): 411-8, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19320567

ABSTRACT

The northeast of Gabon, central Africa is characterized by high population density and a high rate of immigration from the surrounding countries. To determine the prevalence, circulating subtypes, and antiretroviral resistance mutations of HIV-1, 810 blood samples were collected from the general population of the two main cities (Oyem and Makokou) of this region. Of these, 61 (7.5%) were found to be positive for HIV-1. Analysis of the env (gp120), pol, and gag (p24) sequences as well as phylogenetic analyses showed at least eight different viral lineages. The most prevalent strains were CRF02 recombinants, followed by subtypes A, D, and C. The remaining strains were found to be F, J, G, and also, for the first time in Gabon, the recombinant form CRF11cpx. Analysis of antiretroviral drug-resistance mutations in protease and reverse transcriptase from this untreated population showed a low level of specific mutations. These mutations were associated with subtype polymorphism rather than with resistance to antiretroviral drugs. The wide diversity and the emergence of recombinant strains are in accordance with the rapid spread of new HIV strains in the population and, thus, the dynamic evolution of the epidemic.


Subject(s)
Drug Resistance, Viral/genetics , Genetic Variation , HIV Infections/epidemiology , HIV-1/classification , Recombination, Genetic , Adolescent , Adult , Anti-HIV Agents/pharmacology , Female , Gabon/epidemiology , Genes, env/genetics , Genes, gag/genetics , Genes, pol/genetics , HIV Infections/virology , HIV-1/drug effects , HIV-1/genetics , Humans , Male , Middle Aged , Molecular Sequence Data , Mutation , Polymorphism, Genetic , Prevalence , Sequence Analysis, DNA , Young Adult
20.
Virol J ; 5: 158, 2008 Dec 22.
Article in English | MEDLINE | ID: mdl-19102767

ABSTRACT

Hepatitis E virus (HEV) is highly endemic in several African countries with high mortality rate among pregnant women. Nothing is known about the circulation of this virus in central Africa. We evaluated therefore the prevalence of anti-HEV IgG in samples collected from pregnant women living in the five main cities of Gabon, central Africa. We found that 14.1% (119/840) of pregnant women had anti-HEV IgG. The prevalence differed between regions and between age groups. In 391 newly collected samples from the region where the highest prevalence was found, a significant difference (p < 0.05) in seroprevalence was found between rural (6.4%) and urban (13.5%) areas. These data provide evidence of a high prevalence of HEV in Gabon, providing indirect evidence of past contact with this virus.


Subject(s)
Hepatitis E virus/immunology , Hepatitis E/epidemiology , Adolescent , Adult , Female , Gabon/epidemiology , Hepatitis Antibodies/blood , Hepatitis E virus/isolation & purification , Humans , Immunoglobulin G/blood , Pregnancy , Risk Factors , Rural Population , Seroepidemiologic Studies , Urban Population , Young Adult
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