Prevalence and molecular diversity of hepatitis B virus and hepatitis delta virus in urban and rural populations in northern Gabon in central Africa.
Ontology highlight
ABSTRACT:
SUBMITTER: Makuwa M
PROVIDER: S-EPMC2708505 | biostudies-literature | 2009 Jul
REPOSITORIES: biostudies-literature
Publications
Prevalence and molecular diversity of hepatitis B virus and hepatitis delta virus in urban and rural populations in northern Gabon in central Africa.
Makuwa Maria M Mintsa-Ndong Armel A Souquière Sandrine S Nkoghé Dieudonné D Leroy Eric M EM Kazanji Mirdad M
Journal of clinical microbiology 20090513 7
The prevalence of hepatitis B virus (HBV) surface antigen was significantly higher in urban (12.9%) than in rural (7.6%) populations (P = 0.003), but no difference was found in the prevalence of hepatitis delta virus (HDV), which was high in both populations. Phylogenetic analysis showed the circulation of HBV-A3 and -E genotypes and the presence of HDV-1, HDV-7, and HDV-8 clades. ...[more]
Similar Datasets
Project description: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.
| S-EPMC3255803 | biostudies-literature
Project description:BACKGROUND: Hepatitis C virus (HCV) infection is a major global public health problem in both developed and developing countries. The prevalence and genetic diversity of HCV in pregnant women in Gabon, central Africa, is not known. We therefore evaluated the prevalence and the circulating genotypes of HCV in a large population cohort of pregnant women. METHODS: Blood samples (947) were collected from pregnant women in the five main cities of the country. The prevalence was evaluated by two ELISA tests, and the circulating genotypes were characterized by sequencing and phylogenetic analysis. RESULTS: Twenty pregnant women (2.1%) were infected with HCV. The seroprevalence differed significantly by region (p = 0.004) and increased significantly with age (p = 0.05), being 1.3% at 14-20 years, 1.1% at 21-25 years, 1.9% at 26-30 years, 4.1% at 31-35 years and 6.0% at > 35 years. Sequencing in the 5'-UTR and NS5B regions showed that the circulating strains belonged to genotypes 4 (4e and 4c). CONCLUSION: We found that the HCV seroprevalence in pregnant women in Gabon is almost as high as that in other African countries and increases with age. Furthermore, only genotype 4 (4e and 4c) was found. More extensive studies aiming to evaluate the prevalence and heterogeneity of HCV genotypes circulating in the general population of the country are needed.
| S-EPMC2442078 | biostudies-literature
Project description:BackgroundThe 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 findingsA 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/significanceThese 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.
| S-EPMC3411564 | biostudies-literature
Project description:Hepatitis B virus (HBV) surface antigen (HBsAg) was found in 9.2% of 1,186 pregnant women from Gabon, of whom 10.1% had the HBe antigen and 89.9% had anti-HBe antibodies. Antibodies to the hepatitis delta virus (HDV) were found in 15.6% of the HBsAg-positive women. The HBV strains were of the A3 and E genotypes. The HDV strains belonged to HDV clades 1 and 8. These results provide clear evidence that HDV clade 8 is indigenous to Africa.
| S-EPMC2238085 | biostudies-literature
Project description:BackgroundRift Valley fever (RVF) is a mosquito-borne viral zoonosis caused by a phlebovirus and transmitted by Aedes mosquitoes. Humans can also be infected through direct contact with blood (aerosols) or tissues (placenta, stillborn) of infected animals. Although severe clinical cases can be observed, infection with RVF virus (RVFV) in humans is, in most cases, asymptomatic or causes a febrile illness without serious symptoms. In small ruminants RVFV mainly causes abortion and neonatal death. The distribution of RVFV has been well documented in many African countries, particularly in the north (Egypt, Sudan), east (Kenya, Tanzania, Somalia), west (Senegal, Mauritania) and south (South Africa), but also in the Indian Ocean (Madagascar, Mayotte) and the Arabian Peninsula. In contrast, the prevalence of RVFV has rarely been investigated in central African countries.Methodology/principal findingsWe therefore conducted a large serological survey of rural populations in Gabon, involving 4,323 individuals from 212 randomly selected villages (10.3% of all Gabonese villages). RVFV-specific IgG was found in a total of 145 individuals (3.3%) suggesting the wide circulation of Rift Valley fever virus in Gabon. The seroprevalence was significantly higher in the lakes region than in forest and savannas zones, with respective rates of 8.3%, 2.9% and 2.2%. In the lakes region, RVFV-specific IgG was significantly more prevalent in males than in females (respectively 12.8% and 3.8%) and the seroprevalence increased gradually with age in males but not in females.Conclusions/significanceAlthough RVFV was suggested to circulate at a relatively high level in Gabon, no outbreaks or even isolated cases have been documented in the country. The higher prevalence in the lakes region is likely to be driven by specific ecologic conditions favorable to certain mosquito vector species. Males may be more at risk of infection than females because they spend more time farming and hunting outside the villages, where they may be more exposed to mosquito bites and infected animals. Further investigations are needed to determine the putative sylvan cycle of RVFV, including the mosquito species and the reservoir role of wild animals in the viral maintenance cycle.
| S-EPMC2910672 | biostudies-literature
Project description:BackgroundOrf or contagious ecthyma is a zoonotic viral infection with a potential serious health threat for the small ruminants industry as well as humans. It is currently emerging in new territories.ResultsEight suspected clinical cases of pustular dermatitis in goats occurred in the rural area of Tebe, in south-eastern Gabon, in January 2013. The orf virus (ORFV) was detected by high-throughput sequencing on sera, buccal swabs and scab pool samples. It was confirmed in six out of eight sick goats by using specific PCR targeting the major envelope protein (B2L) and the orf virus interferon resistance (VIR) genes. Phylogenetic analysis revealed that the Gabonese strain and South Korean strains evolved from a common ancestor, suggesting an Asian origin of the ORFV' Gabonese strain.ConclusionsThis study provides the molecular detection of the ORFV strain involved in the cases of pustular dermatitis in goats and highlights its circulation in Gabon.
| S-EPMC4866431 | biostudies-literature
Project description:The molecular basis of evolutionary change is assumed to be genetic variation. However, growing evidence suggests that epigenetic mechanisms, such as DNA methylation, may also be involved in evolutionary change. An important first step in evaluating this hypothesis is to test for the presence of epigenetic variation between natural populations living under different environmental conditions. In the current study we explored variation between populations of Darwin’s finches living in adjacent “urban” and “rural” environments on Santa Cruz Island in the Galápagos. We tested for morphological, genetic, and epigenetic differences between the urban and rural populations of each of two species of ground finches, Geospiza fortis and G. fuliginosa. Using data collected from more than 1000 birds, we found significant morphological differences between populations of G. fortis, but not G. fuliginosa. We did not find genetic differences between populations of either species, based on comparisons of copy number variation (CNV). In contrast, we did find epigenetic differences between the urban and rural populations of both species, based on DNA methylation analysis. We explored genomic features and gene associations of the differentially methylated regions (DMR), as well as their possible functional significance. In summary, our study documents local population epigenetic variation within species of Darwin’s finches.
2017-01-07 | GSE87825 | GEO
Project description:BackgroundChikungunya 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 findingsSample 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/significanceWe 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.
| S-EPMC3916288 | biostudies-literature
Project description:BackgroundHuman T-Lymphotropic Virus type 1 (HTLV-1) is a human oncoretrovirus that infects at least 5 to 10 million people worldwide and is associated with severe diseases. Africa appears as the largest HTLV-1 endemic area. However, the risk factors for the acquisition of HTLV-1 remain poorly understood in Central Africa.MethodsWe conducted an epidemiological survey between 2013 and 2017, in rural areas of 6 provinces of Gabon, in a rainforest environment. Epidemiological data were obtained and blood samples were collected after informed consent. Plasma were screened for HTLV-1 antibodies by ELISA and the positive samples were then tested by Western blot (WB). Genomic DNA derived from buffy-coat was subjected to two semi-nested PCRs amplifying either HTLV-1 env gene or LTR region fragments.ResultsWe recruited 2,060 individuals over 15 years old, including 1,205 men and 855 women (mean age: 49 years). Of these, 299 were found to be ELISA HTLV-1/2 seropositive. According to WB criteria, 136 were HTLV-1 (6.6%), 25 HTLV-1/2 (1.2%) and 9 HTLV seroreactive (0.4%). PCR results showed that 146 individuals were positive for at least one PCR: 104 for the env gene and 131 for the LTR region. Based on both serological and molecular results, 179 individuals were considered infected with HTLV-1, leading to an overall prevalence of 8.7%. The distribution of HTLV-1 infection was heterogeneous across the country. Based on multivariable analyses, female gender, increasing age, ethnicity (Pygmy) and multiple hospitalizations (more than 5 times) were found to be independent risk factors for HTLV-1 infection. Furthermore, a non-human primate bite appeared to be marginally associated with a higher risk of HTLV-1 infection.ConclusionBased on state-of-the-art serological and molecular methods, we have demonstrated that rural adult populations in Gabon are highly endemic for HTLV-1. Our results regarding risk factors should lead to public health actions aiming to reduce HTLV-1 transmission.
| S-EPMC6200283 | biostudies-literature
Project description:Epigenetic variation has the potential to control environmentally dependent development and contribute to phenotypic responses to local environments. Environmental epigenetic studies of sexual organisms confirm the responsiveness of epigenetic variation, which should be even more important when genetic variation is lacking. A previous study of an asexual snail, Potamopyrgus antipodarum, demonstrated that different populations derived from a single clonal lineage differed in both shell phenotype and methylation signature when comparing lake versus river populations. Here, we examine methylation variation among lakes that differ in environmental disturbance and pollution histories. The differential DNA methylation regions (DMRs) identified among the different lake comparisons suggested a higher number of DMRs and variation between rural Lake 1 and one urban Lake 2 and between the two urban Lakes 2 and 3, but limited variation between the rural Lake 1 and urban Lake 3. DMR genomic characteristics and gene associations were investigated. Observations suggest there is no effect of geographic distance or any consistent pattern of DMRs between urban and rural lakes. Environmental factors may influence epigenetic response.
2019-09-27 | GSE133502 | GEO