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1.
BMC Res Notes ; 14(1): 152, 2021 Apr 20.
Article in English | MEDLINE | ID: mdl-33879229

ABSTRACT

OBJECTIVE: Herd immunity is achieved when in a population, immune individuals are in a sufficiently large proportion. Neutralizing antibodies specific to SARS-CoV-2 that are produced following infection or vaccination are critical for controlling the spread of COVID-19. The objective of the present work was to investigate the rate of SARS-CoV-2 natural immunization in Gabonese. RESULTS: One thousand, four hundred and ninety two people were enrolled. The overall prevalence of anti-SARS-CoV-2 antibodies was 36.2%. Moreover, 76.4% of people who developed a humoral response to SARS-CoV-2 produced both anti-SARS-CoV-2 N-protein antibodies and anti-SARS-CoV-2 S-protein antibodies, which correspond to 27.7% of the total population. In infants (0-9 month), children (1-17 years) and adults, the prevalence of anti-SARS-CoV-2 antibodies was relatively the same, between 33 and 37% (any antibody types) and between 25 and 28.6% (neutralizing antibodies). In this African context, one-third (1/3) of the screened population was exposed to SARS-CoV-2 and three-quarter (3/4) of those exposed individuals developed neutralizing antibodies against SARS-CoV-2. This data suggest that herd immunity is not yet to be achieved in Gabon.


Subject(s)
Antibodies, Viral/immunology , /immunology , Immunity, Herd , Spike Glycoprotein, Coronavirus/immunology , Adolescent , Adult , Aged , Antibodies, Neutralizing/immunology , Child , Child, Preschool , Female , Gabon/epidemiology , Humans , Infant , Infant, Newborn , Male , Middle Aged , Phosphoproteins/immunology , Young Adult
2.
BMC Infect Dis ; 21(1): 265, 2021 Mar 17.
Article in English | MEDLINE | ID: mdl-33731022

ABSTRACT

BACKGROUND: Increasing arbovirus infections have been a global burden in recent decades. Many countries have experienced the periodic emergence of arbovirus diseases. However, information on the prevalence of arboviruses is largely unknown or infrequently updated because of the lack of surveillance studies, especially in Africa. METHODS: A surveillance study was conducted in Gabon, Central Africa, on arboviruses, which are a major public health concern in Africa, including: West Nile virus (WNV), dengue virus (DENV), Zika virus (ZIKV), yellow fever virus (YFV), chikungunya virus (CHIKV), and Rift Valley fever virus (RVFV). Serological and molecular assays were performed to investigate past infection history and the current status of infection, using serum samples collected from healthy individuals and febrile patients, respectively. RESULTS: The overall seroprevalence during 2014-2017 was estimated to be 25.3% for WNV, 20.4% for DENV, 40.3% for ZIKV, 60.7% for YFV, 61.2% for CHIKV, and 14.3% for RVFV. No significant differences were found in the seroprevalence of any of the viruses between the male and female populations. However, a focus on the mean age in each arbovirus-seropositive individual showed a significantly younger age in WNV- and DENV-seropositive individuals than in CHIKV-seropositive individuals, indicating that WNV and DENV caused a relatively recent epidemic in the region, whereas CHIKV had actively circulated before. Of note, this indication was supported by the detection of both WNV and DENV genomes in serum samples collected from febrile patients after 2016. CONCLUSIONS: This study revealed the recent re-emergence of WNV and DENV in Gabon as well as the latest seroprevalence state of the major arboviruses, which indicated the different potential risks of virus infections and virus-specific circulation patterns. This information will be helpful for public health organizations and will enable a rapid response towards these arbovirus infections, thereby preventing future spread in the country.


Subject(s)
Arboviruses/isolation & purification , Dengue/epidemiology , Zika Virus Infection/epidemiology , Adolescent , Animals , Arbovirus Infections/diagnosis , Arbovirus Infections/epidemiology , Arboviruses/classification , Child , Child, Preschool , Communicable Diseases, Emerging , Dengue/diagnosis , Female , Fever/epidemiology , Fever/virology , Gabon/epidemiology , Humans , Infant , Male , Public Health , Seroepidemiologic Studies , Zika Virus Infection/diagnosis
3.
Viruses ; 13(2)2021 01 25.
Article in English | MEDLINE | ID: mdl-33503816

ABSTRACT

Human herpesvirus 8 (HHV-8) is the etiological agent of all forms of Kaposi's sarcoma (KS). K1 gene studies have identified five major molecular genotypes with geographical clustering. This study described the epidemiology of HHV-8 and its molecular diversity in Gabon among Bantu and Pygmy adult rural populations and KS patients. Plasma antibodies against latency-associated nuclear antigens (LANA) were searched by indirect immunofluorescence. Buffy coat DNA samples were subjected to polymerase chain reaction (PCR) to obtain a K1 gene fragment. We studied 1020 persons; 91% were Bantus and 9% Pygmies. HHV-8 seroprevalence was 48.3% and 36.5% at the 1:40 and 1:160 dilution thresholds, respectively, although the seroprevalence of HHV-8 is probably higher in Gabon. These seroprevalences did not differ by sex, age, ethnicity or province. The detection rate of HHV-8 K1 sequence was 2.6% by PCR. Most of the 31 HHV-8 strains belonged to the B genotype (24), while the remaining clustered within the A5 subgroup (6) and one belonged to the F genotype. Additionally, we reviewed the K1 molecular diversity of published HHV-8 strains in Africa. This study demonstrated a high seroprevalence of HHV-8 in rural adult populations in Gabon and the presence of genetically diverse strains with B, A and also F genotypes.


Subject(s)
Herpesvirus 8, Human/genetics , Sarcoma, Kaposi/epidemiology , Sarcoma, Kaposi/virology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , Antigens, Viral/immunology , DNA, Viral/genetics , Female , Gabon/epidemiology , Genetic Variation , Genotype , Herpesvirus 8, Human/classification , Herpesvirus 8, Human/immunology , Herpesvirus 8, Human/isolation & purification , Humans , Male , Middle Aged , Nuclear Proteins/immunology , Phylogeny , Rural Population , Seroepidemiologic Studies , Viral Proteins/genetics , Young Adult
4.
BMC Infect Dis ; 20(1): 718, 2020 Sep 29.
Article in English | MEDLINE | ID: mdl-32993559

ABSTRACT

BACKGROUND: Schistosoma antigen detection in urine is a valuable diagnostic approach for schistosomiasis control programmes because of the higher sensitivity compared to parasitological methods and preferred sampling of urine over stool. Highly accurate diagnostics are important in low Schistosoma transmission areas. Pregnant women and young children could particularly benefit from antigen testing as praziquantel (PZQ) can be given to only confirmed Schistosoma cases. This prevents the unborn baby from unnecessary exposure to PZQ. We present here the protocol of a diagnostic study that forms part of the freeBILy project. The aim is to evaluate the accuracy of circulating anodic antigen (CAA) detection for diagnosis of Schistosoma haematobium infections in pregnant women and to validate CAA as an endpoint measure for anti-Schistosoma drug efficacy. The study will also investigate Schistosoma infections in infants. METHODS: A set of three interlinked prospective, observational studies is conducted in Gabon. The upconverting phosphor lateral flow (UCP-LF) CAA test is the index diagnostic test that will be evaluated. The core trial, sub-study A, comprehensively evaluates the accuracy of the UCP-LF CAA urine test against a set of other Schistosoma diagnostics in a cross-sectional trial design. Women positive for S. haematobium will proceed with sub-study B and will be randomised to receive PZQ treatment immediately or after delivery followed by weekly sample collection. This approach includes comparative monitoring of CAA levels following PZQ intake and will also contribute further data for safety of PZQ administration during pregnancy. Sub-study C is a longitudinal study to determine the incidence of S. haematobium infection as well as the age for first infection in life-time. DISCUSSION: The freeBILy trial in Gabon will generate a comprehensive set of data on the accuracy of the UCP-LF CAA test for the detection of S. haematobium infection in pregnant women and newborn babies and for the use of CAA as a marker to determine PZQ efficacy. Furthermore, incidence of Schistosoma infection in infants will be reported. Using the ultrasensitive diagnostics, this information will be highly relevant for Schistosoma prevalence monitoring by national control programs as well as for the development of medicaments and vaccines. TRIAL REGISTRATION: The registration number of this study is NCT03779347 ( clinicaltrials.gov , date of registration: 19 December 2018).


Subject(s)
Antigens, Helminth/analysis , Immunologic Tests/methods , Schistosoma haematobium/immunology , Schistosomiasis haematobia/diagnosis , Schistosomiasis haematobia/epidemiology , Animals , Anthelmintics/therapeutic use , Child, Preschool , Cross-Sectional Studies , Data Accuracy , Female , Follow-Up Studies , Gabon/epidemiology , Humans , Infant , Infant, Newborn , Longitudinal Studies , Praziquantel/therapeutic use , Pregnancy , Prevalence , Prospective Studies , Real-Time Polymerase Chain Reaction , Schistosoma haematobium/genetics , Schistosomiasis haematobia/drug therapy , Schistosomiasis haematobia/parasitology
5.
Eur Rev Med Pharmacol Sci ; 24(15): 8226-8231, 2020 08.
Article in English | MEDLINE | ID: mdl-32767354

ABSTRACT

OBJECTIVE: To explore whether the climate has played a role in the COVID-19 outbreak, we compared virus lethality in countries closer to the Equator with others. Lethality in European territories and in territories of some nations with a non-temperate climate was also compared. MATERIALS AND METHODS: Lethality was calculated as the rate of deaths in a determinate moment from the outbreak of the pandemic out of the total of identified positives for COVID-19 in a given area/nation, based on the COVID-John Hopkins University website. Lethality of countries located within the 5th parallels North/South on 6 April and 6 May 2020, was compared with that of all the other countries. Lethality in the European areas of The Netherlands, France and the United Kingdom was also compared to the territories of the same nations in areas with a non-temperate climate. RESULTS: A lower lethality rate of COVID-19 was found in Equatorial countries both on April 6 (OR=0.72 CI 95% 0.66-0.80) and on May 6 (OR=0.48, CI 95% 0.47-0.51), with a strengthening over time of the protective effect. A trend of higher risk in European vs. non-temperate areas was found on April 6, but a clear difference was evident one month later: France (OR=0.13, CI 95% 0.10-0.18), The Netherlands (OR=0.5, CI 95% 0.3-0.9) and the UK (OR=0.2, CI 95% 0.01-0.51). This result does not seem to be totally related to the differences in age distribution of different sites. CONCLUSIONS: The study does not seem to exclude that the lethality of COVID-19 may be climate sensitive. Future studies will have to confirm these clues, due to potential confounding factors, such as pollution, population age, and exposure to malaria.


Subject(s)
Climate , Coronavirus Infections/mortality , Pneumonia, Viral/mortality , Seasons , Weather , Betacoronavirus , Brunei/epidemiology , Burundi/epidemiology , Congo/epidemiology , Coronavirus Infections/epidemiology , Ecuador/epidemiology , Equatorial Guinea/epidemiology , Europe , France/epidemiology , Gabon/epidemiology , Humans , Indian Ocean Islands/epidemiology , Indonesia/epidemiology , Kenya/epidemiology , Malaysia/epidemiology , Melanesia/epidemiology , Micronesia/epidemiology , Netherlands/epidemiology , Pandemics , Papua New Guinea/epidemiology , Pneumonia, Viral/epidemiology , Rwanda/epidemiology , Samoa/epidemiology , Sao Tome and Principe/epidemiology , Seychelles/epidemiology , Singapore/epidemiology , Somalia/epidemiology , Timor-Leste/epidemiology , Tropical Climate , Uganda/epidemiology , United Kingdom/epidemiology
6.
PLoS One ; 15(7): e0235329, 2020.
Article in English | MEDLINE | ID: mdl-32702035

ABSTRACT

INTRODUCTION: Pregnancy termination is one of the key issues that require urgent attention in achieving the third Sustainable Development Goal (SDG) of ensuring healthy lives and promoting well-being for all at all ages. The reproductive health decision-making (RHDM) capacity of women plays a key role in their reproductive health outcomes, including pregnancy termination. Based on this premise, we examined RHDM capacity and pregnancy termination among women of reproductive age in sub-Saharan Africa (SSA). MATERIALS AND METHODS: We pooled data from the women's files of the most recent Demographic and Health Surveys (DHS) of 27 countries in SSA, which are part of the DHS programme. The total sample was 240,489 women aged 15 to 49. We calculated the overall prevalence of pregnancy termination in the 27 countries as well as the prevalence in each individual country. We also examined the association between RHDM capacity, socio-demographic characteristics and pregnancy termination. RHDM was generated from two variables: decision-making on sexual intercourse and decision-making on condom use. Binary logistic regression analysis was conducted and presented as Crude Odds Ratios (COR) and Adjusted Odds Ratios (AOR) with their corresponding 95% confidence intervals (CI). Statistical significance was declared p<0.05. RESULTS: The prevalence of pregnancy termination ranged from 7.5% in Benin to 39.5% in Gabon with an average of 16.5%. Women who were capable of taking reproductive health decisions had higher odds of terminating a pregnancy than those who were incapable (AOR = 1.20, 95% CI = 1.17-1.24). We also found that women aged 45-49 (AOR = 5.54, 95% CI = 5.11-6.01), women with primary level of education (AOR = 1.14, 95% CI = 1.20-1.17), those cohabiting (AOR = 1.08, 95% CI = 1.04-1.11), those in the richest wealth quintile (AOR = 1.06, 95% CI = 1.02-1.11) and women employed in the services sector (AOR = 1.35, 95% CI = 1.27-1.44) were more likely to terminate pregnancies. Relatedly, women who did not intend to use contraceptive (AOR = 1.47, 95% CI = 1.39-1.56), those who knew only folkloric contraceptive method (AOR = 1.25, 95% CI = 1.18-1.32), women who watched television almost every day (AOR = 1.16, 95% CI = 1.20-1.24) and those who listened to radio almost every day (AOR = 1.11, 95% CI = 1.04-1.18) had higher odds of terminating a pregnancy. However, women with four or more children had the lowest odds (AOR = 0.5, 95% CI = 0.54-0.60) of terminating a pregnancy. CONCLUSION: We found that women who are capable of taking reproductive health decisions are more likely to terminate pregnancies. Our findings also suggest that age, level of education, contraceptive use and intention, place of residence, and parity are associated with pregnancy termination. Our findings call for the implementation of policies or the strengthening of existing ones to empower women about RHDM capacity. Such empowerment could have a positive impact on their uptake of safe abortions. Achieving this will not only accelerate progress towards the achievement of maternal health-related SDGs but would also immensely reduce the number of women who die as a result of pregnancy termination in SSA.


Subject(s)
Abortion, Induced/psychology , Reproductive Health/trends , Women's Health/trends , Adolescent , Adult , Africa South of the Sahara , Benin/epidemiology , Clinical Decision-Making , Contraception Behavior/psychology , Contraceptive Agents/therapeutic use , Female , Gabon/epidemiology , Health Surveys , Humans , Middle Aged , Pregnancy , Women's Health/statistics & numerical data , Young Adult
8.
Sci Rep ; 10(1): 7314, 2020 04 30.
Article in English | MEDLINE | ID: mdl-32355260

ABSTRACT

Little research on coronaviruses has been conducted on wild animals in Africa. Here, we screened a wide range of wild animals collected in six provinces and five caves of Gabon between 2009 and 2015. We collected a total of 1867 animal samples (cave-dwelling bats, rodents, non-human primates and other wild animals). We explored the diversity of CoVs and determined the factors driving the infection of CoVs in wild animals. Based on a nested reverse transcription-polymerase chain reaction, only bats, belonging to the Hipposideros gigas (4/156), Hipposideros cf. ruber (13/262) and Miniopterus inflatus (1/249) species, were found infected with CoVs. We identified alphacoronaviruses in H. gigas and H. cf. ruber and betacoronaviruses in H. gigas. All Alphacoronavirus sequences grouped with Human coronavirus 229E (HCoV-229E). Ecological analyses revealed that CoV infection was significantly found in July and October in H. gigas and in October and November in H. cf ruber. The prevalence in the Faucon cave was significantly higher. Our findings suggest that insectivorous bats harbor potentially zoonotic CoVs; highlight a probable seasonality of the infection in cave-dwelling bats from the North-East of Gabon and pointed to an association between the disturbance of the bats' habitat by human activities and CoV infection.


Subject(s)
Alphacoronavirus/genetics , Betacoronavirus/genetics , Caves , Chiroptera/virology , Coronavirus Infections/epidemiology , Genetic Variation , Animals , Base Sequence/genetics , Coronavirus 229E, Human/genetics , Coronavirus Infections/virology , Gabon/epidemiology , Humans , Insectivora/virology , Phylogeny , Prevalence , Primates/genetics , RNA, Viral/genetics , RNA, Viral/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction , Rodentia/genetics , Seasons
9.
BMC Infect Dis ; 20(1): 350, 2020 May 15.
Article in English | MEDLINE | ID: mdl-32414337

ABSTRACT

BACKGROUND: Pediatric diarrhea caused by a range of pathogens, including intestinal parasites, is one of main causes of death among children under 5 years of age. The distribution of these parasitic infections overlaps in many environmental, socioeconomic and epidemiological settings. Their distribution and prevalence varies from region to region. In the current study, we assess the prevalence of intestinal parasites among pediatric patients with syndromic diarrheal disease living in Franceville, Gabon. METHODS: A cross-sectional study conducted in the Amissa Bongo Regional Hospital and Chinese-Gabonese Friendship Hospital in Franceville, between November 2016 and August 2017, enrolled a total of 100 diarrheic children between 0 and 180 months of age. Parasite detection in stool samples was performed using molecular diagnostic by PCR. Difference in means were tested by Student's t test and ANOVA while principal component analysis was used to determine the correlation between parasite distributions and age groups. RESULTS: The overall prevalence of intestinal parasite infection was 61% (61/100). Hymenolepis sp and Cryptosporidium hominis/parvum were the most common parasites (31 and 19%, respectively), followed by Encephalitozoon intestinalis (15%), Trichuris trichiura (4%), Dientamoeba fragilis (4%), and Enterocytozoon bieneusi (2%). The polyparasitism rate was 19.7%, with 83.3% double and 16.7% triple infections. Protozoan infections (66.7%) were more prevalent than helminths infections (33.3%). Seasonal association of the circulation of intestinal parasite was statistically significant (p = 0.03). Correlations between different parasites was also observed. CONCLUSION: The prevalence of intestinal parasitic infections is highest in diarrheic pediatric children. The prevalence of parasitic infections indicates that protozoa and helminths are the most common parasites in the Franceville environment. This study reinforces the importance of routine examination of diarrheic stool samples for the diagnostic of intestinal parasites. Further analyses are required to better understand the local epidemiology and risk factors associated with the transmission of intestinal parasites in Franceville, Gabon. KEYSWORDS: diarrhea, children, intestinal parasitic infections, molecular diagnostic, Franceville, Gabon.


Subject(s)
Diarrhea/parasitology , Helminthiasis/epidemiology , Intestinal Diseases, Parasitic/epidemiology , Protozoan Infections/epidemiology , Animals , Child, Preschool , Cross-Sectional Studies , Cryptosporidiosis/epidemiology , Cryptosporidiosis/parasitology , Cryptosporidium/genetics , Diarrhea/epidemiology , Feces/parasitology , Female , Gabon/epidemiology , Humans , Infant , Male , Polymerase Chain Reaction , Prevalence , Protozoan Infections/parasitology , Risk Factors
10.
Am J Trop Med Hyg ; 103(1): 325-333, 2020 07.
Article in English | MEDLINE | ID: mdl-32431272

ABSTRACT

Schistosomiasis is a parasitic infection highly prevalent in Central Africa where it is co-endemic with many other parasitic infections, including soil-transmitted helminths (STHs). For its optimal control, there is a need of descriptive epidemiological data for each endemic region. The objective of the present study was to determine the epidemiological situation around schistosomiasis in Lambaréné, Gabon. A cross-sectional study was conducted among schoolchildren. One urine sample per day was collected on three consecutive days for the diagnosis of schistosomiasis using a urine filtration technique. One stool sample was collected for the detection of Schistosoma spp. and STH spp. eggs using the Kato-Katz technique, and for larvae, using the coproculture technique. A total of 614 schoolchildren were included in the analysis. The overall prevalence of schistosomiasis and STH infections was 26% (159/614) and 15% (70/473), respectively. Human-freshwater contact was the main risk factor for schistosomiasis in the area (relative risk (RR) = 2.96 [2.20-4.00], P < 0.001). Hematuria (RR = 5.53 [4.30-7.10], P < 0.001) and proteinuria (RR = 2.12 [1.63-2.75], P < 0.001) as well as infection with Trichuris trichiura (RR = 1.86 [1.33-2.61], P = 0.002) and Ascaris lumbricoides (RR = 1.96 [1.19-3.21], P = 0.039) were associated with an increased risk of schistosomiasis. Trichuris trichiura was the highest prevalent STH species in the area. Our study reports a moderate prevalence for schistosomiasis with human-water contact as the main risk factor, whereas the prevalence of STH infections appears to be low. Our results stress the need for the implementation of WHO recommendations for schistosomiasis control.


Subject(s)
Ascariasis/epidemiology , Schistosomiasis haematobia/epidemiology , Trichuriasis/epidemiology , Adolescent , Albendazole/therapeutic use , Anthelmintics/therapeutic use , Ascariasis/drug therapy , Child , Coinfection/epidemiology , Cross-Sectional Studies , Culture Techniques , Feces/parasitology , Female , Gabon/epidemiology , Hematuria/epidemiology , Hookworm Infections/drug therapy , Hookworm Infections/epidemiology , Humans , Male , Praziquantel/therapeutic use , Prevalence , Proteinuria/epidemiology , Risk Factors , Schistosomiasis haematobia/drug therapy , Strongyloidiasis/drug therapy , Strongyloidiasis/epidemiology , Trichuriasis/drug therapy
11.
J Parasitol ; 106(2): 221-232, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32164028

ABSTRACT

Members of the sucking louse genus Pedicinus are ectoparasites of cercopithecid primates in Africa, Asia, and Gibraltar. Pedicinus gabonensis n. sp. is described on the basis of adult male and female specimens collected from the mandrill (Mandrillus sphinx) in Gabon. The new species is compared morphologically with other members of the genus Pedicinus, and a nuclear elongation factor 1 alpha gene sequence is provided. Host associations and geographical distributions of the 18 previously recognized species of the genus and of P. gabonensis n. sp. are reviewed. Updated identification keys are provided for males and females of all known valid species of Pedicinus.


Subject(s)
Anoplura/classification , Lice Infestations/veterinary , Mandrillus/parasitology , Monkey Diseases/parasitology , Animals , Anoplura/anatomy & histology , Anoplura/genetics , Anoplura/physiology , DNA/chemistry , DNA/isolation & purification , Female , Gabon/epidemiology , Lice Infestations/epidemiology , Lice Infestations/parasitology , Male , Monkey Diseases/epidemiology , Sequence Alignment/veterinary , Sequence Analysis, DNA/veterinary
12.
Sci Rep ; 10(1): 2080, 2020 02 07.
Article in English | MEDLINE | ID: mdl-32034188

ABSTRACT

The causes of infections in pediatric populations differ between age groups and settings, particularly in the tropics. Such differences in epidemiology may lead to misdiagnosis and ineffective empirical treatment. Here, we investigated the current spectrum of pathogens causing febrile diseases leading to pediatric hospitalization in Lambaréné, Gabon. From August 2015 to March 2016, we conducted a prospective, cross-sectional, hospital-based study in a provincial hospital. Patients were children ≤ 15 years with fever ≥ 38 °C and required hospitalization. A total of 600 febrile patients were enrolled. Malaria was the main diagnosis found in 52% (311/600) patients. Blood cultures revealed septicemia in 3% (17/593), among them four cases of typhoid fever. The other causes of fever were heterogeneously distributed between both bacteria and viruses. Severe infections identified by Lambaréné Organ Dysfunction Score (LODS) were also most often caused by malaria, but children with danger signs did not have more coinfections than others. In 6% (35/600) of patients, no pathogen was isolated. In Gabon, malaria is still the major cause of fever in children, followed by a bacterial and viral disease. Guidelines for both diagnosis and management should be tailored to the spectrum of pathogens and resources available locally.


Subject(s)
Fever/etiology , Infections/complications , Child , Child, Preschool , Cross-Sectional Studies , Female , Gabon/epidemiology , Hospitals/statistics & numerical data , Humans , Infant , Infections/epidemiology , Infections/microbiology , Infections/virology , Malaria/complications , Malaria/epidemiology , Male , Organ Dysfunction Scores , Prospective Studies , Sepsis/complications , Sepsis/epidemiology , Typhoid Fever/complications , Typhoid Fever/epidemiology
13.
Int J Infect Dis ; 91: 129-136, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31821892

ABSTRACT

OBJECTIVES: Dengue outbreaks, mainly caused by dengue virus serotype 2 (DENV-2), occurred in 2007 and in 2010 in Gabon, Central Africa. However, information on DENV infections has been insufficient since 2010. The aim of this study was to investigate the current DENV infection scenario and the risk of repeated infections in Gabon. METHODS: During 2015-2017, serum samples were collected from enrolled febrile participants and were tested for DENV infection using RT-qPCR. DENV-positive samples were analyzed for a history of previous DENV infection(s) using ELISA. The complete DENV genome was sequenced to analyze the phylogeny of Gabonese DENV strains. RESULTS: DENV-3 was exclusively detected, with a high rate of anti-DENV IgG seropositivity among DENV-3-positive participants. DENV-3 showed higher infection rates in adults and the infection was seasonal with peaks in the rainy seasons. Phylogenetic analysis revealed that Gabonese DENV-3 originated from West African strains and has been circulating continuously in Gabon since at least 2010, when the first DENV-3 case was reported. CONCLUSIONS: These findings indicate stable DENV-3 circulation and the risk of repeated DENV infections in Gabon, highlighting the need for continuous monitoring to control DENV infections.


Subject(s)
Dengue Virus/isolation & purification , Dengue/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Dengue/virology , Dengue Virus/classification , Dengue Virus/genetics , Female , Gabon/epidemiology , Humans , Infant , Male , Middle Aged , Phylogeny , Real-Time Polymerase Chain Reaction , Seasons , Seroepidemiologic Studies , Serogroup , Young Adult
14.
Am J Trop Med Hyg ; 102(1): 121-129, 2020 01.
Article in English | MEDLINE | ID: mdl-31769404

ABSTRACT

The epidemiology of febrile illness etiologies is under-explored in resource-poor settings. Establishing a local repertory of microorganisms circulating in blood of febrile and afebrile people is important for physicians. Blood was collected from 428 febrile and 88 afebrile children in Makokou (Gabon) and analyzed using polymerase chain reaction. Plasmodium spp. were the pathogens, which were most detected in febrile children (69.6%; 298/428) and in afebrile children (31.8%; 28/88) (P < 0.0001). Plasmodium falciparum was the most prevalent species in both febrile and afebrile children (66.8% and 27.3%, respectively). No differences were observed between febrile and afebrile children for Plasmodium malariae and Plasmodium ovale (8.2% versus 10.2% and 3.3% versus 3.4%, respectively). Triple infection with P. falciparum, P. malariae, and P. ovale was also detected in 1% of febrile children (4/428). Filariasis due to Mansonella perstans was detected in 10 febrile patients (2.3%), whereas Loa loa was detected in both febrile and afebrile children (1.4% and 2.3%, respectively). Bacterial DNA was detected in only 4.4% (19/428) of febrile children, including 13 (68.4%) who were coinfected with at least one Plasmodium species. These were Haemophilus influenzae (1.6%, 7/428), Streptococcus pneumoniae and Staphylococcus aureus (1.2%, 5/428), and Rickettsia felis (0.9%, 4/428). Coxiella burnetii, Bartonella spp., Borrelia spp., Tropheryma whipplei, Anaplasma spp., Leptospira spp., Streptococcus pyogenes, and Salmonella spp. were not detected. This study also highlights the over-prescription and the overuse of antibiotics and antimalarials. Overall, malaria remains a major health problem in Makokou. Malaria control measures must be reconsidered in this region.


Subject(s)
Bacteremia/epidemiology , Fever/etiology , Malaria/epidemiology , Bacteremia/microbiology , Bacteria/classification , Child , Child, Preschool , Female , Gabon/epidemiology , Humans , Infant , Malaria/complications , Malaria/diagnosis , Malaria/parasitology , Male , Prevalence
15.
Afr Health Sci ; 20(3): 1024-1034, 2020 Sep.
Article in English | MEDLINE | ID: mdl-33402948

ABSTRACT

Introduction: Intestinal parasites infections are endemic in Gabon. Nevertheless, they are rarely described in people living with HIV (PLHIV). Objective: The frequency of intestinal parasite infection was estimated and compared between HIV-positive and HIV uninfected individuals in Gabon; factors associated with intestinal parasites were also analysed. Material and Methods: Using a cross-sectional study design sociodemographic data, life style habits, antiretroviral therapy, cotrimoxazole use and CD4 cell count were recorded.. Stool samples from participants living in Koulamoutou and Oyem were analysed using microscopy. Chi-squared or fisher's exact tests and logistic regression were performed. Results: Among participants (n=332), female gender was predominant (73.7%; n=135/183) and the median age was 45 [33-57] years old. Among 183 samples, 53.6% (n = 98/183) were infected by intestinal parasites. The proportion was higher (72.1%) in HIV negative participants compared to PLHIV (42.6%) (p <0.01). PLHIV were more frequently poly-infected. Infection was frequent in patients using external toilets and tap water (>70.0%). Conclusion: Prevalence of intestinal parasites is higher in seronegative participants but polyparasitism is more frequent in PLHIV. Strategies are focused on HIV negative population, but this study shows the importance of sensitization for PLHIV to improve their quality of life.


Subject(s)
Feces/parasitology , HIV Infections/complications , Intestinal Diseases, Parasitic/epidemiology , Adolescent , Adult , Antiretroviral Therapy, Highly Active , Carrier State , Coinfection/epidemiology , Cross-Sectional Studies , Female , Gabon/epidemiology , HIV Infections/drug therapy , HIV Infections/epidemiology , Humans , Male , Middle Aged , Prevalence , Quality of Life , Risk Factors , Rural Population , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use
16.
Parasit Vectors ; 12(1): 577, 2019 Dec 10.
Article in English | MEDLINE | ID: mdl-31823806

ABSTRACT

BACKGROUND: Sub-Saharan Africa carries most of the global burden of schistosomiasis. To optimize disease control and reduce morbidity, precise data are needed for control measures adapted to the local epidemiological situation. The objective of this study is to provide baseline information on schistosomiasis dynamics, including praziquantel (PZQ) treatment outcome in children and young adults living in the vicinity of Lambaréné, Gabon. METHODS: Eligible volunteers were included into a prospective longitudinal study. Urine filtration technique was used to detect eggs in urine for schistosomiasis diagnosis. Subjects were treated with 60 mg of PZQ once per month for three consecutive months, and the outcome was assessed by cure rate (CR) and egg reduction rate (ERR). RESULTS: A total of 328 volunteers were enrolled in the study with a mean (± SD) age of 12.2 ± 4.7 years-old. The female-to-male ratio was 0.99. Out of 258 participants in total, 45% had schistosomiasis during the survey and 43% presented with heavy infections. The incidences of haematuria and schistosomiasis were 0.11 and 0.17 person-years, respectively. After the first and third dose of PZQ, overall ERR of 93% and 95% were found, respectively; while the CR were 78% and 88%, respectively. Both ERR (100 vs 88%) and CR (90 vs 68%) were higher among females than males after the first dose. The CR increased for both groups after the third dose to 95% and 80%, respectively. After the first PZQ dose, ERR was higher for heavy compared to light infections (94 vs 89%), while the CR was higher for light than for heavy infections (87 vs 59%). After the third PZQ dose, ERR increased only for light infections to 99%, while CR increased to 98% and 75% for light and for heavy infections, respectively. The reinfection rate assessed at a mean of 44.6 weeks post-treatment was 25%. CONCLUSIONS: The prevalence of schistosomiasis is moderate in communities living in the vicinity of Lambaréné, where a subpopulation with a high risk of reinfection bears most of the burden of the disease. To improve schistosomiasis control in this scenario, we suggest education of these high-risk groups to seek themselves a one-year PZQ treatment. Trial registration clinicaltrials.gov Identifier NCT02769103. Registered 11 May 2016, retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT02769013.


Subject(s)
Anthelmintics/administration & dosage , Praziquantel/administration & dosage , Schistosomiasis haematobia/drug therapy , Schistosomiasis haematobia/epidemiology , Adolescent , Child , Child, Preschool , Female , Gabon/epidemiology , Humans , Incidence , Longitudinal Studies , Male , Parasite Egg Count , Prevalence , Prospective Studies , Recurrence , Retrospective Studies , Schistosomiasis haematobia/pathology , Treatment Outcome , Young Adult
17.
Malar J ; 18(1): 371, 2019 Nov 21.
Article in English | MEDLINE | ID: mdl-31752891

ABSTRACT

BACKGROUND: Malaria remains a public health issue, particularly in sub-Saharan Africa with special features of seriousness in young children and pregnant women. Adolescents and adults are reported to have acquired a semi-immune status and, therefore, present with low parasitaemia. Children are understood to present with a much higher parasitaemia and severe malaria. It is a concern that effective malaria control programmes targeting young children may lead to a delay in the acquisition of acquired immunity and, therefore, causing a shift in the epidemiology of malaria. Prevalence and parasitaemia were explored in adolescents and adults with Plasmodium falciparum infections compared to young children in the area of Lambaréné, Gabon as an indicator for semi-immunity. METHODS: A cross-sectional study was conducted at the Centre de Recherches Médicales de Lambaréné (CERMEL) during a 6-month period in 2018. Symptomatic patients, of all ages were screened for malaria at health facilities in Lambaréné and Fougamou and their respective surrounding villages in the central region of Gabon. Plasmodium falciparum infections were determined either by rapid diagnostic test (RDT) or by microscopy. Descriptive analysis of data on parasite densities, anaemia, and fever are presented. RESULTS: 1589 individuals screened were included in this analysis, including 731 (46%) adolescents and adults. Out of 1377 assessed, the proportion of P. falciparum positive RDTs was high among adolescents (68%) and adults (44%), compared to young children (55%) and school children (72%). Out of 274 participants assessed for malaria by microscopy, 45 (16%) had a parasite count above 10,000/µl of which 9 (20%) were adults. CONCLUSION: This study shows a high rate of P. falciparum infections in adolescents and adults associated with high-level parasitaemia similar to that of young children. Adolescents and adults seem to be an at-risk population, suggesting that malaria programmes should consider adolescents and adults during the implementation of malaria prevention and case management programmes with continuous care, since they also act as reservoirs for P. falciparum.


Subject(s)
Malaria, Falciparum/epidemiology , Parasitemia/epidemiology , Plasmodium falciparum/isolation & purification , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cross-Sectional Studies , Female , Gabon/epidemiology , Humans , Infant , Infant, Newborn , Malaria, Falciparum/parasitology , Male , Middle Aged , Parasitemia/parasitology , Prevalence , Prospective Studies , Young Adult
18.
Sci Rep ; 9(1): 14753, 2019 10 14.
Article in English | MEDLINE | ID: mdl-31611571

ABSTRACT

Complexes of closely related species provide key insights into the rapid and independent evolution of adaptive traits. Here, we described and studied Anopheles fontenillei sp.n., a new species in the Anopheles gambiae complex that we recently discovered in the forested areas of Gabon, Central Africa. Our analysis placed the new taxon in the phylogenetic tree of the An. gambiae complex, revealing important introgression events with other members of the complex. Particularly, we detected recent introgression, with Anopheles gambiae and Anopheles coluzzii, of genes directly involved in vectorial capacity. Moreover, genome analysis of the new species allowed us to clarify the evolutionary history of the 3La inversion. Overall, An. fontenillei sp.n. analysis improved our understanding of the relationship between species within the An. gambiae complex, and provided insight into the evolution of vectorial capacity traits that are relevant for the successful control of malaria in Africa.


Subject(s)
Anopheles/genetics , Malaria/transmission , Mosquito Vectors/genetics , Animals , Biological Evolution , Evolution, Molecular , Female , Gabon/epidemiology , Genome, Insect , Humans , Malaria/epidemiology , Phylogeny
19.
J Mycol Med ; 29(4): 317-319, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31481349

ABSTRACT

BACKGROUND: Vulvovaginal candidiasis (VVC) is one of the most common lower genital tract infections in women; this unpleasant and extremely embarrassing pathology is one of the main reasons for gynaecological consultation. In Gabon, the prevalence of VVC remains poorly described even though VVC is known to be the leading gynaecological condition in several countries. This retrospective cross-sectional study sought to assess the prevalence of VVC among symptomatic women in southeastern Gabon. METHODS: Clinical samples were collected from patients suspected to have VVC during a 2-year period (from January 2016 to December 2017). Gram staining of vaginal smears provided indications of vaginal flora and confirmed the presence of yeast. Sabouraud-chloramphenicol and chromID Candida media were used to isolate yeast, and species identification was performed using morphological tests and the Vitek 2 Compact automated system. RESULTS: For the 873 patients included in this study, the prevalence of VVC was 28.52%. Eleven Candida species were identified, with greater representation of Candidaalbicans (82.73%) than of Non C. albicanscandida (NCAC) (17.27%), which were distributed as follows: Candidafamata (4.02%), Candida spp. (3.61%), Candidarugosa (3.21%), Candidalipolytica (1.61%), Candidaparapsilosis (1.61%), Candidaglabrata (1.21%), Candidatropicalis (0.80%), Candidakrusei (0.40%), Candidadubliniensis (0.40%), and Candidasphaerica (0.40%). CONCLUSION: This study offers the first estimation of VVC among Gabonese women in childbearing age with the symptoms. It showed that VVC is very common in Gabon. C. albicans as the most commonly represented species.


Subject(s)
Candida/classification , Candidiasis, Vulvovaginal/epidemiology , Candidiasis, Vulvovaginal/microbiology , Vagina/microbiology , Candida/isolation & purification , Candidiasis, Vulvovaginal/diagnosis , Cross-Sectional Studies , Female , Gabon/epidemiology , Humans , Prevalence , Retrospective Studies
20.
Emerg Infect Dis ; 25(10): 1851-1860, 2019 10.
Article in English | MEDLINE | ID: mdl-31538557

ABSTRACT

Pregnant women constitute a promising sentinel group for continuous monitoring of malaria transmission. To identify antibody signatures of recent Plasmodium falciparum exposure during pregnancy, we dissected IgG responses against VAR2CSA, the parasite antigen that mediates placental sequestration. We used a multiplex peptide-based suspension array in 2,354 samples from pregnant women from Mozambique, Benin, Kenya, Gabon, Tanzania, and Spain. Two VAR2CSA peptides of limited polymorphism were immunogenic and targeted by IgG responses readily boosted during infection and with estimated half-lives of <2 years. Seroprevalence against these peptides reflected declines and rebounds of transmission in southern Mozambique during 2004-2012, reduced exposure associated with use of preventive measures during pregnancy, and local clusters of transmission that were missed by detection of P. falciparum infections. These data suggest that VAR2CSA serology can provide a useful adjunct for the fine-scale estimation of the malaria burden among pregnant women over time and space.


Subject(s)
Antigens, Protozoan/blood , Malaria, Falciparum/complications , Pregnancy Complications, Parasitic/epidemiology , Adult , Antibodies, Protozoan/immunology , Antigens, Protozoan/immunology , Benin/epidemiology , Female , Gabon/epidemiology , Humans , Immunoglobulin G/immunology , Kenya/epidemiology , Malaria, Falciparum/diagnosis , Malaria, Falciparum/epidemiology , Malaria, Falciparum/transmission , Mozambique/epidemiology , Plasmodium falciparum/immunology , Pregnancy , Pregnancy Complications, Parasitic/blood , Pregnancy Complications, Parasitic/diagnosis , Serologic Tests/methods , Spain/epidemiology , Tanzania/epidemiology , Young Adult
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