Determinants of low birth weight in Franceville, Southeast Gabon.

Introduction: birth weight is a critical indicator of neonatal health and predicts future developmental outcomes. Despite its importance, there is a notable lack of research on the determinants of low birth weight (LBW) in southeast Gabon. This study aims to fill this gap by identifying factors contributing to LBW at the Centre Hospitalier Universitaire Amissa Bongo in Franceville. Methods: this retrospective analysis covered the period from February 2011 to May 2017, focusing on postpartum women and their infants. Data were analyzed using R software (version 4.3.2), employing both descriptive statistics and logistic regression. Statistical significance was determined at a p-value of less than 0.05. Results: among the 877 births analyzed, the prevalence of LBW was 8.4%. Bivariate analysis identified several factors associated with an increased risk of LBW, including, primigravida women (COR (95%CI) =0.59 (0.36-0.98), P = 0.036), primiparous women (COR (95%CI) =0.58 (0.36-0. 94), P = 0.024), women with a gestational age <37 weeks (COR (95%CI) =0.07 (0.04-0.11), P<0.001), women with ≤2 antenatal visits (COR (95%CI) =0.39 (0.18-0.93), P= 0.021), and women who underwent cesarean delivery (COR (95%CI) =0.46 (0.26-0.84), P = 0.008). However, multivariate analysis showed that only gestational age (AOR (95%CI) = 0.07 (0.04-0.11), P<0.001) and cesarean delivery (AOR (95%CI) = 0.48 (0.25-0.95), P = 0.03) were significantly associated with LBW. Conclusion: this study highlights the importance of gestational age and delivery method in the prevalence of LBW in southeast Gabon. These findings underscore the need for targeted interventions to address these risk factors, thereby improving neonatal health outcomes.

Antibacterial and antioxidant activities of plants consumed by western lowland gorilla (Gorilla gorilla gorilla) in Gabon.

Zoopharmacognosy is the study of the self-medication behaviors of non-human animals that use plant, animal or soil items as remedies. Recent studies have shown that some of the plants employed by animals may also be used for the same therapeutic purposes in humans. The aim of this study was to determine the antioxidant and antibacterial activity of Ceiba pentandra, Myrianthus arboreus, Ficus subspecies (ssp.) and Milicia excelsa bark crude extracts (BCE), plants consumed by western lowland gorillas (Gorilla gorilla gorilla) in Moukalaba-Doudou National Park (MDNP) and used in traditional medicine, and then to characterize their phytochemical compounds. DPPH (2,2-Diphenyl-1-Picrylhydrazyl), phosphomolybdenum complex and ß-carotene bleaching methods were used to assess antioxidant activity. Antimicrobial susceptibility testing was performed using the diffusion method, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed using the microdilution method. The highest level of total phenolics was found in Myrianthus arboreus aqueous extract [385.83 ± 3.99 mg [gallic acid equivalent (GAE)/g]. Total flavonoid (134.46 ± 3.39) mg quercetin equivalent (QE)/100 g of extract] were highest in Milicia excelsa, tannin [(272.44 ± 3.39) mg tannic acid equivalent (TAE)/100 g of extract] in Myrianthus arboreus and proanthocyanidin [(404.33 ± 3.39) mg apple procyanidins equivalent (APE)/100 g of extract] in Ceiba pentandra. Ficus ssp. (IC50 1.34 ±3.36 µg/mL; AAI 18.57 ± 0.203) ethanolic BCE and Milicia excelsa (IC50 2.07 ± 3.37 µg/mL; AAI 12.03 ± 0.711) showed the strongest antioxidant activity. Myrianthus arboreus ethanolic BCE (73.25 ± 5.29) and Milicia excelsa aqueous BCE (38.67 ± 0.27) showed the strongest percentage of total antioxidant capacity (TAC). Ceiba pentandra ethanolic BCE (152.06 ± 19.11 mg AAE/g) and Ficus ssp aqueous BCE (124.33 ± 39.05 mg AAE/g) showed strongest relative antioxidant activity (RAA). The plant BCE showed antimicrobial activity against multidrug resistant (MDR) E. coli (DECs) isolates, with MICs varying from 1.56 to 50 mg/mL and inhibition diameters ranging from 7.34 ± 0.57 to 13.67 ± 0.57mm. Several families of compounds were found, including total phenolic compounds, flavonoids, tannins and proanthocyanidins were found in the plant BCEs. The plant BCEs showed antioxidant activities with free radical scavenging and antimicrobial activities against 10 MDR E. coli (DECs) isolates, and could be a promising novel source for new drug discovery.

HIV-1 residual risk and pre-treatment drug resistance among blood donors: A sentinel surveillance from Gabon.

BACKGROUND: Surveillance of HIV-1 pre-treatment drug resistance (PDR) is essential for ensuring the success of first-line antiretroviral therapy (ART). Beside population-based surveys, sentinel surveillance of PDR and circulating HIV-1 clades in specific populations such as blood donors could efficiently inform decision-making on ART program. We therefore sought to ascertain HIV-1 residual infection, the threshold of PDR and viral diversity among recently-diagnosed blood donors in Gabon. METHODS: A sentinel surveillance was conducted among 381 consenting blood donors at the National Blood Transfusion Center (NBTC) in Gabon from August 3,2020 to August, 31, 2021. In order to determine the residual risk of HIV transmission, viral load and HIV-1 Sanger-sequencing were performed at the Chantal BIYA International Reference Center (CIRCB)-Cameroon on HIV samples previously tested seronegative with ELISA in Gabon. Phylogeny was performed using MEGA X, PDR threshold>10% was considered high and data were analysed using p≤0.05 for statistical significance. RESULTS: Five HIV-negative blood donors had a detectable viral load indicating a high residual risk of HIV transmission. Among the samples successfully sequenced, four participants had major drug resistance mutations (DRMs), giving a threshold of PDR of 25% (4/16). By drug class, major DRMs targeting NNRTI (K103N, E138G), NRTIs (L210W) and PI/r (M46L). The most representative viral clades were CRF02_AG and subtype A1. The genetic diversity of HIV-1 had no significant effect on the residual risk in blood transfusion (CRF02_AG, P = 0.3 and Recombinants, P = 0.5). CONCLUSION: This sentinel surveillance indicates a high residual risk of HIV-1 transfusion in Gabon, thereby underscoring the need for optimal screening strategy for blood safety. Moreover, HIV-1 transmission goes with high-risk of PDR, suggesting suboptimal efficacy of ART. Nonetheless, the genetic diversity has limited (if any effect) on the residual risk of infection and PDR in blood donors.

Neopterin production in relation to COVID-19 in the Haut-Ogooué Province, Gabon.

BACKGROUND: In sub-Saharan Africa, understanding of the immune process associated with the COVID-19 pandemic remains scarce. This study aimed to investigate the relationship between plasma neopterin concentrations and COVID-19 infection, focusing on changes over time and age-related changes in immune response. METHODS: A retrospective case study was conducted during the first wave of COVID-19 from March to August 2020. Whole blood and associated symptoms and comorbidities were collected from patients of all ages and sexes. Concentrations of plasma neopterin were measured using a commercial competitive neopterin ELISA (Neopterin ELISA, IBL International GmbH, Germany). RESULTS: We analyzed data for 325 patients: 38% (n = 124) with COVID-19, and 62% (n = 201) without COVID-19, as a control group. We found that plasma neopterin concentrations were significantly higher in the COVID-19 group (mean value 45.1 nmol/L (SD 19)) than in the control group (mean value 33.8 nmol/L (SD 13)) (p = 0.004). In addition, neopterin levels decreased gradually over time in patients with COVID-19 (p < 0.001). Moreover, ROC analysis found that the best cut-off value for diagnosing COVID-19 patients based on plasma neopterin levels was 38.85 nmol/L with 70% sensitivity and 82% specificity (AUC, 0.74 [0.69-0.82], p < 0.05). We also found an increase in neopterin production with increasing age (p < 0.001). CONCLUSION: Our findings contribute to our growing understanding of neopterin levels as a promising biomarker for the detection of COVID-19 cases in sub-Saharan Africa.

Reported healthcare-seeking of loiasis patients and estimation of the associated monetary burden in Gabon: Data from a cross-sectional survey.

BACKGROUND: Loiasis is a disease of relevance in endemic populations and there has been advocacy for its inclusion on the World Health Organization's neglected tropical diseases list. As loiasis-related healthcare-seeking behaviors and related costs are unknown, we aimed to evaluate these aspects in a population residing in an endemic region in Gabon. METHODS: Data were collected during a community-based, cross-sectional study assessing the disease burden due to loiasis. Diagnostics for microfilaremia were performed and a history of eyeworm was obtained. In addition, a standardized questionnaire about type of healthcare resources and frequency of use, as well as respective associated costs was administered to each participant. Loiasis related healthcare-seeking behaviors were evaluated, and the associated monetary burden was estimated as a secondary outcome of the study. FINDINGS: Individuals diagnosed with loiasis more frequently reported any healthcare-seeking (OR 1.52 (95%CI: 1.21-1.91)), self-medicating (OR 1.62 (1.26-2.08)), inability to work (OR 1.86 (1.47-2.35)), and consulting with traditional healers (logOdds 1.03 (0.52-1.53)), compared to loiasis negative individuals. The most frequently reported treatment for the eyeworm was traditional herbs. The estimated healthcare associated costs, per positive individual, was US-$ 58 (95% CI: 21-101) per year, which would correspond to 3.5% of the reported mean household income. Extrapolation to the rural population of Gabon (n = 204,000), resulted in an annual monetary burden estimate of US-$ 3,206,000 (1,150,000-5,577,000). INTERPRETATION: Loiasis patients have demonstrated healthcare needs, often consulted traditional healers, and used traditional treatments for disease specific symptoms. Further, loiasis seems to be associated with substantial direct and indirect costs for individuals and thus may cause a relevant economic burden for endemic populations and economies of affected countries.

Prevalence and factors associated with transfusion-transmissible infections (HIV, HBV, HCV and Syphilis) among blood donors in Gabon: Systematic review and meta-analysis.

BACKGROUND: Transfusion-transmissible infections (TTIs) remain a major public health problem in countries with limited resources, particularly in Gabon. Complete information on the prevalence in Gabon of the main TTIs among blood donors is still lacking in the national context. The purpose of this systematic review and meta-analysis was to determine the prevalence and factors associated with TTIs among blood donors in Gabon. METHODS: This systematic review and meta-analysis was reported in accordance with the PRISMA 2020 guidelines. It was the result of data from several comprehensive studies published between 2014 and 2022, the purpose of which focused on the prevalence and factors associated with TTIs among blood donors in Gabon. The quality of the articles was assessed using the Joanna Briggs Institute critical appraisal checklist for studies reporting prevalence data. The overall prevalence of TTIs among blood donors was determined using the random effects model. Heterogeneity between studies was assessed using I2 statistics. Publication bias was assessed by visual inspection of the funnel plot and Egger's statistics. RESULTS: A total of 175,140 blood donors from the nine eligible studies were admitted to this study. The combined prevalence of HIV, HBV, HCV and syphilis obtained in the random effects model was 3.0%, 6.0%, 4.0% and 3.0%, respectively. Moreover, being a male blood donor and aged between 25 and 44 years was significantly associated with HBV infection and being a female blood donor and aged 35 years and over was significantly associated with HIV infection. Family or replacement blood donors had a high infection burden for all four TTIs of study. CONCLUSION: The overall prevalence of transfusion-transmissible infections remains high in the country's blood banks. Improving current prevention (selection criteria) and screening strategies may be necessary in a global approach.

Genetic diversity of Plasmodium malariae in sub-Saharan Africa: a two-marker genotyping approach for molecular epidemiological studies.

Introduction: Plasmodium malariae is the most common non-falciparum species in sub-Saharan Africa. Despite this, data on its genetic diversity is scarce. Therefore, we aimed to establish a P. malariae genotyping approach based on size polymorphic regions that can be easily applied in molecular epidemiological studies. Methods: Four potential genotyping markers, Pm02, Pm09, P. malariae thrombospondin-related anonymous protein (pmtrap), and P. malariae merozoite surface protein fragment 2 (pmmsp1 F2) were amplified via nested PCR and analysed using automated capillary gel electrophoresis. Results: We observed the highest allelic diversity for pmtrap (MOI = 1.61) and pmmsp1 F2 (He = 0.81). Further applying the two markers pmtrap and pmmsp1 F2 on a different sample set of 21 P. malariae positive individuals followed up over one week, we saw a high consistency in their performance. The results show a large complexity and high dynamics of P. malariae infections in the asymptomatic Gabonese study population. Discussion: We successfully implemented a new genotyping panel for P. malariae consisting of only two markers: pmtrap and pmmsp1 F2. It can be easily applied in other settings to investigate the genotype diversity of P. malariae populations, providing further important data on the molecular epidemiology of this parasite species.

Replication, safety and immunogenicity of the vectored Ebola vaccine rVSV-ΔG-ZEBOV-GP in a sub-Saharan African paediatric population: A randomised controlled, open-label trial in children aged 1-12 years living in Lambaréné, Gabon.

BACKGROUND: Unlike adults, children experienced stronger and longer vector replication in plasma and shedding in saliva following rVSVΔG-ZEBOV-GP vaccination. The resulting risks of immunosuppression or immune hyperactivation leading to increased Adverse Events (AEs) and altered antibody responses are concerns that have been addressed in the present manuscript. METHODS: Children aged 1-12 years living in Gabon received either rVSVΔG-ZEBOV-GP (ERVEBO®) vaccine or the varicella-zoster virus (VZV) vaccine (VZV). The concentration of rVSVΔG vector in blood and saliva, the occurrence of AEs up to day 28; the anti-rVSVΔG-ZEBOV-GP and anti-VZV IgG antibody titres, neutralising and avidity functions of anti-rVSVΔG-ZEBOV-GP by day 365; were assessed in serum. (PACTR202005733552021) FINDINGS: In the rVSVΔG-ZEBOV-GP group, 70% and 7% of children had >0 copies/ml of rVSVΔG respectively in plasma by day 3 and in saliva by day 14 after vaccination, with no detection on day 28. Significantly higher but transient AEs occurred in the rVSVΔG-ZEBOV-GP group. Both vaccines induced seroconversion on day 28 and sustainable IgG antibody titres by day 365. Avidity and neutralisation functions of the anti-rVSVΔG-ZEBOV-GP antibodies peaked at day 28 and were maintained by day 365. INTERPRETATION: The replication and shedding do not affect the favourable risk-benefit balance of the rVSVΔG-ZEBOV-GP in children.

Focal spleen lesions in loiasis: A pilot study in Gabon.

BACKGROUND: Infection with the filarial nematode Loa loa, endemic in Central and Western Africa, has been associated with increased morbidity and mortality. A number of reports described the presence of spleen nodules, originating from degenerating microfilariae, in humans and animals infected with L. loa. The long-term consequences of this process on individuals chronically exposed to infection in terms of spleen function and possible link with excess mortality are unknown. The aim of this study was to evaluate the prevalence of focal spleen lesions, their evolution over time, and markers of spleen function, in individuals with L. loa infection living in highly endemic areas of Gabon. METHODOLOGY/PRINCIPAL FINDINGS: This was a cross-sectional study followed by a longitudinal study of the subset of individuals with spleen nodules. Two hundred sixteen participants from Ngounié and Moyen-Ogooué provinces of Gabon, reporting a history of eyeworm migration and/or Calabar swelling, were included. Participants were categorized into infected microfilaraemic with low (N = 74) and high (N = 10) microfilaraemia, and symptomatic amicrofilaraemic (N = 132), based on blood microscopy. Howell-Jolly bodies in erythrocytes, as indirect marker of spleen functional impairment, were within normal ranges. On ultrasound, no evident signs of spleen fibrosis or hypotrophy were observed. Multiple spleen hypoechoic centimetric macronodules were observed in 3/216 participants (1.4%), all with microfilaraemic L. loa infection (3.4% of microfilaraemics); macrondules disappeared at the 6-months follow-up examination in 2/3 individuals. Spleen hypoechoic micronodules, persisting at the 6-months follow-up, were detected in 3/216 participants (1.4%), who were all amicrofilaraemic. CONCLUSIONS/SIGNIFICANCE: Transitory spleen macronodules are present in a small but consistent proportion of individuals with microfilaraemic loiasis, appearing a rather benign phenomenon in terms of impact on spleen morphology and function. Their occurrence should be taken into consideration to avoid misdiagnosis and mistreatment. Prevalence and significance of spleen micronodular ultrasound patterns in the general population would be also worth evaluating.

[Pre-extensively and extensively drug-resistant tuberculosis, in Libreville, Gabon]. / Tuberculose pré- et ultrarésistante à Libreville, Gabon.

INTRODUCTION: Very few studies have been devoted to extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis (TB) in Gabon. AIM: The aim of the present study is to present the epidemiology of pre-XDR and XDR TB and the evolution over time of patients with multidrug-resistant TB. METHODS: This retrospective study covered the activities from 2019 to 2022 of the Nkembo anti-tuberculosis center. RESULTS: Fifteen patients were eligible, including 11 (73.3%) pre-XDR patients and 4 (26.7%) XDR-TB patients. Three (20.0%) patients had HIV/TB co-infection. The sample consisted of 7 men (46.7%) and 8 women (53.3%), a sex ratio (M/F) of 0.87. The average age was 35.6 years, and the median 34 years, with extremes of 23 and 60 years. Eight patients (53.3%) represented new cases of pre-XDR or XDR-TB tuberculosis. The majority (60%; n=9) came from deprived neighborhoods with widespread promiscuity. The therapeutic success rate among pre-XDR patients was 4 (36.4%) versus 2 (50.0%) among XDR-TB patients. Reported mortality occurred 5 (33.3%) patients during treatment, including 3 pre-XDR and 2 XDR-TB patients. In all cases, they died before the end of the first trimester of follow-up. CONCLUSION: The high frequency of primary pre-extensively drug-resistant tuberculosis underscores the pervasiveness of resistance to anti-tuberculosis drugs and underlines a pressing need for detection of contact cases and early treatment.

Slow clearance of histidine-rich protein-2 in Gabonese with uncomplicated malaria.

Malaria rapid diagnostic tests (RDTs), which detect Plasmodium falciparum (Pf)-specific histidine-rich protein-2 (HRP2), have increasing importance for the diagnosis and control of malaria, especially also in regions where routine diagnosis by microscopy is not available. HRP2-based RDTs have a similar sensitivity to expert microscopy, but their reported low specificity can lead to high false positivity rates, particularly in high-endemic areas. Despite the widespread use of RDTs, models investigating the dynamics of HRP2 clearance following Pf treatment focus rather on short-term clearance of the protein. The goal of this observational cohort study was to determine the long-term kinetic of HRP2-levels in peripheral blood after treatment of uncomplicated malaria cases with Pf mono-infection using a 3-day course of artesunate/amodiaquine. HRP2 levels were quantified at enrollment and on days 1, 2, 3, 5, 7, 12, 17, 22, and 28 post-treatment initiation. The findings reveal an unexpectedly prolonged clearance of HRP2 after parasite clearance from capillary blood. Terminal HRP2 half-life was estimated to be 9 days after parasite clearance using a pharmacokinetic two-compartmental elimination model. These results provide evidence that HRP2 clearance has generally been underestimated, as the antigen remains detectable in capillary blood for up to 28 days following successful treatment, influencing RDT-based assessment following a malaria treatment for weeks. A better understanding of the HRP2 clearance dynamics is critical for guiding the diagnosis of malaria when relying on RDTs. IMPORTANCE: Detecting Plasmodium falciparum, the parasite responsible for the severest form of malaria, typically involves microscopy, polymerase chain reaction (PCR), or rapid diagnostic tests (RDTs) targeting the histidine-rich protein 2 or 3 (HRP2/3). While microscopy and PCR quickly turn negative after the infection is cleared, HRP2 remains detectable for a prolonged period. The exact duration of HRP2 persistence had not been well defined. Our study in Gabon tracked HRP2 levels over 4 weeks, resulting in a new model for antigen clearance. We discovered that a two-compartment model accurately predicts HRP2 levels, revealing an initial rapid reduction followed by a much slower elimination phase that can take several weeks. These findings are crucial for interpreting RDT results, as lingering HRP2 can lead to false positives, impacting malaria diagnosis and treatment decisions.

First Detection of Antibodies Specific to Crimean-Congo Hemorrhagic Fever Virus in Rural Populations of Gabon.

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease with a mortality rate reaching up to 40% in humans. Currently, CCHF affects three continents: Asia, Europe, and Africa. An increase in confirmed cases in Africa has been observed since 2000. In Central Africa, several countries have reported the circulation of CCHV virus (CCHFV). However, in Gabon, there is a lack of recent data on the circulation of the virus in the Gabonese population. To provide an overview of the epidemiological situation in Gabon, we tested 3,081 human serum samples collected between 2005 and 2008 in villages throughout the country for anti-CCHFV antibodies. Using a double-antigen ELISA kit, our study found 15/3,081 samples positive for CCHFV. These positive samples were also tested using the Blackbox CCHFV IgG kit and the Luminex technique. These analyses confirmed seven and four positives for the Blackbox CCHFV IgG kit and the Luminex technique, respectively. This study suggests low circulation of CCHFV in the rural human population of Gabon. Competent authorities must survey CCHFV to identify and prevent clinical cases in the human population.

Prevalence and Genetic Diversity of Bat Hepatitis B Viruses in Bat Species Living in Gabon.

Hepatitis B virus (HBV) infection leads to around 800,000 deaths yearly and is considered to be a major public health problem worldwide. However, HBV origins remain poorly understood. Here, we looked for bat HBV (BtHBV) in different bat species in Gabon to investigate the role of these animals as carriers of ancestral hepadnaviruses because these viruses are much more diverse in bats than in other host species. DNA was extracted from 859 bat livers belonging to 11 species collected in caves and villages in the southeast of Gabon and analyzed using PCRs targeting the surface gene. Positive samples were sequenced using the Sanger method. BtHBV DNA was detected in 64 (7.4%) individuals belonging to eight species mainly collected in caves. Thirty-six (36) sequences among the 37 obtained after sequencing were phylogenetically close to the RBHBV strain recently isolated in Gabonese bats, while the remaining sequence was close to a rodent HBV strain isolated in America. The generalized linear mixed model showed that the variable species best explained the occurrence of BtHBV infection in bats. The discovery of a BtHBV strain homologous to a rodent strain in bats raises the possibility that these animals may be carriers of ancestral hepadnaviruses.

Recurring Transient Tooth Pain as Newly Described Symptom of Migratory Loiasis: A Mixed-Methods Study in Rural Gabon.

Loiasis, a filarial pathogen exclusively endemic in central and western Africa, causes a wide spectrum of symptoms. Understanding the breadth of its clinical manifestations is of importance for adequate patient care and to understand its disease burden. Recurring transient pain in the oral cavity was reported as a self-perceived symptom of loiasis in in-depth interviews of patients in a high transmission region in Gabon. Pain was described as stabbing in character and transient for a few days in its temporal course. A quantitative epidemiological survey indicated that transient tooth pain was experienced by 22% of patients infected with Loa loa. Among those individuals, it was exclusively reported by patients suffering from migratory loiasis (24%). Similar findings have been previously described for other filarial pathogens, indicating that transient swellings of the periodontium and the soft tissue of the oral cavity may explain this symptom reported by patients with migratory loiasis.

No evidence of mpox virus circulation in putative animal reservoirs in Gabon wildlife.

OBJECTIVES: Mpox is a neglected viral endemic tropical disease in Central and Western African countries transmitted to humans by an animal. However, the natural reservoir of the virus remains elusive. In this study, we looked for potential reservoirs of the mpox virus (MPXV) in Gabonese wildlife to prevent future outbreaks and enrich the literature with additional data on animal reservoirs. METHODS: DNA was extracted from the livers and spleens from 2549 animals (bats [859], bushmeats [356], rodents [1309], and shrews [25]) collected between 2012 and 2021. DNA was analyzed by real-time and conventional polymerase chain reaction, targeting the 14 kD protein and the rpo subunit RNA polymerase of orthopoxviruses. RESULTS: No MPXV DNA was detected despite the presence of potential host reservoirs such as Critcetomys, Crocidura, Praomys, and Atherurus africanus. This absence could be due to (i) the low number of animals collected for some species, (ii) the acute nature of mpox infection but also (iii) the lack of the potential reservoir Funisciurus anerythrus among collected animals, and (iv) the fact that the samplings are not included in the probable ecological niche of MPXV. CONCLUSION: Longitudinal studies including potential ecological niches of F. anerythrus and MPXV in Gabon may be useful to get more information on MPXV circulation.

Epidemiology of malaria in Gabon: A systematic review and meta-analysis from 1980 to 2023.

The objective of this were conducted to elucidate spatiotemporal variations in malaria epidemiology in Gabon since 1980. For that, five databases, were used to collect and identify all studies published between 1980 and 2023 on malaria prevalence, antimalarial drug resistance, markers of antimalarial drug resistance and insecticide resistance marker. The findings suggest that Gabon continues to face malaria as an urgent public health problem, with persistently high prevalence rates. Markers of resistance to CQ persist despite its withdrawal, and markers of resistance to SP have emerged with a high frequency, reaching 100 %, while ACTs remain effective. Also, recent studies have identified markers of resistance to the insecticides Kdr-w and Kdr-e at frequencies ranging from 25 % to 100 %. Ace1R mutation was reported with a frequency of 0.4 %. In conclusion, the efficacy of ACTs remains above the threshold recommended by the WHO. Organo-phosphates and carbamates could provide an alternative for vector control.

Molecular surveillance for dengue serotypes among the population living in Moyen-Ogooué province, Gabon; evidence of the presence of dengue serotype 1.

BACKGROUND: Despite dengue virus (DENV) outbreak in Gabon a decade ago, less is known on the potential circulation of DENV serotypes in the country. Previous studies conducted in some areas of the country, are limited to hospital-based surveys which reported the presence of some cases of serotype 2 and 3 seven years ago and more recently the serotype 1. As further investigation, we extend the survey to the community of Moyen Ogooué region with the aim to assess the presence of the dengue virus serotypes, additionally to characterize chikungunya (CHIKV) infection and describe the symptomatology associated with infections. METHOD: A cross-sectional survey was conducted from April 2020 to March 2021. The study included participants of both sexes and any age one year and above, with fever or history of fever in the past seven days until blood collection. Eligible volunteers were clinically examined, and blood sample was collected for the detection of DENV and CHIKV using RT-qPCR. Positive samples were selected for the target sequencing. RESULTS: A total of 579 volunteers were included. Their mean age (SD) was 20 (20) years with 55% of them being female. Four cases of DENV infection were diagnosed giving a prevalence of 0.7% (95%CI: 0.2-1.8) in our cohort while no case of CHIKV was detected. The common symptoms and signs presented by the DENV cases included fatigue, arthralgia myalgia, cough, and loss of appetite. DENV-1was the only virus detected by RT-qPCR. CONCLUSION: Our results confirm the presence of active dengue infection in the region, particularly DENV-1, and could suggest the decline of DENV-2 and DENV-3. Continuous surveillance remains paramount to comprehensively describe the extent of dengue serotypes distribution in the Moyen-Ogooué region of Gabon.

Temporal trends of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus in Gabon.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of mortality due to bacterial antimicrobial resistance. While S. aureus is common in skin and soft tissue infections (SSTI) in Africa, data on MRSA rates are scarce and reports vary widely across the continent (5%-80%). In this study, we describe the proportion of MRSA causing SSTI in Lambaréné, Gabon, over an 11-year period. METHODS: We retrospectively analyzed data from 953 bacterial specimens collected from inpatients and outpatients with SSTI at the Albert Schweitzer Hospital, Lambaréné, Gabon, between 2009 and 2019. We determined temporal changes in the prevalence of MRSA and identified risk factors for SSTI with MRSA. RESULTS: 68% of all specimens with bacterial growth yielded S. aureus (n = 499/731), of which 7% (36/497) with antimicrobial susceptibility testing were identified as MRSA. Age above 18 years, admission to the surgical ward, and deep-seated infections were significantly associated with MRSA as the causative agent. After an initial decline from 7% in 2009, there was a marked increase in the proportion of MRSA among all S. aureus from SSTI from 3 to 20% between 2012 and 2019. The resistance rate to erythromycin was significantly higher in MRSA than in methicillin-susceptible S. aureus (73% vs. 10%), and clindamycin resistance was detected exclusively in MRSA isolates (8%). CONCLUSION: The increasing proportion of MRSA causing SSTI over the 11-year period contrasts with many European countries where MRSA is on decline. Continuous surveillance of MRSA lineages in the hospital and community along with antibiotic stewardship programs could address the increasing trend of MRSA.

Consumers of insect-based foods: a cross-cultural study between Belgium and Gabon.

Human consumption of insects has previously been examined in cross-cultural studies. However, such studies rarely include African countries and willingness-to-pay for insect-based food has never been assessed in cross-cultural studies. The current study presents a cross-cultural study conducted with 409 urban dwellers from Belgium (191 males; 218 females) and 412 urban dwellers from Gabon (219 males; 193 females). Each respondent was surveyed with a questionnaire following the Knowledge, Attitude, and Practices model and included questions relative to willingness-to-pay for 2 insect-based foods (insect baguette and insect burger). More than 90% of respondents from both countries were familiar with edible insects. However, acceptance of entomophagy was lower in respondents from Gabon than in respondents from Belgium. Intercultural differences were also recorded between Gabonese ethnic groups. Most respondents who accepted entomophagy were willing to eat the insect baguette and/or the insect burger. These findings confirm that entomophagy could further develop in Belgium and Gabon. Willingness-to-pay varied between countries and between insect-based foods. In Belgium, the average prices of comparable conventional foods (i.e., same foods but without insects) were lower than the average willingness-to-pay for insect-based foods. In Gabon, respondents were not willing to pay extra for insect-based foods. Setting the right price for insect-based foods is a necessary step to promote more frequent insect consumption.