Added Value of Mean Blood Pressure and Placental Growth Factor in the Early Detection of Pre-eclampsia among Gabonese Women.

OBJECTIVE: To evaluate the use of the Foetal Medicine Foundation (FMF) algorithm in routine practice for early pre-eclampsia (PE) screening in Libreville. MATERIALS AND METHODS: We conducted a cohort study on pregnant women within their 11-13 + 6 weeks of gestation (WG). We had measured mean blood pressure (MBP), placental growth factor (PlGF), soluble Fms-like tyrosine kinase 1, Uterine Artery Pulsatility Index (UtA-PI) and resistance index (UtA-RI). Statistical analyses were considered significant for P < 0.05. RESULTS: There were 30 participants. At the first quarter (T1), 36.7% of them were at high risk of PE according to the FMF algorithm and were consequently prescribed aspirin (100 mg/d). By the end of the observation period, we have found a 13% incidence of PE. MBP was higher in the higher risk PE group than in the lower risk group as early as the T1 (90 ± 6 vs. 81 ± 6 mmHg; P = 0.0007, threshold is >86 mmHg/area under the curve (AUC) = 0.86; P = 0.0012). It was the same for PlGF (58 ± 24 vs. 88 ± 38 pg/ml; P = 0.03; threshold is <71.98 pg/ml/AUC = 0.73; P = 0.03). At the second quarter (20-27 WG), biochemical markers did not change between the two groups. UtA-RI, UtA-PI and notch were unconclusive individually, but they are still very important for FMF algorithm application. CONCLUSION: Early detection of PE using the FMF algorithm is possible in routine practice in Gabon. MBP and PlGF levels at T1 seem to be very significant. However, the present study must continue to obtain the larger cohorts that would achieve more conclusive statistical analyses.

État des lieux du système d'information sanitaire du Gabon.

OBJECTIVE: The need for an efficient and reliable health information system motivated Gabon, with the support of the World Bank, to finance a project to reinforce its health information system. An audit of this system was required to report on the reality of the existing system and tools. METHODS: Over the course of two periods, May to September 2016 and April to May 2018, information was collected using both qualitative and quantitative approaches. In this framework, were carried out successively: participative workshops including health actors in Gabon, a survey of health care workers, an analysis of reference documents relating to national health policies, and an analysis of the strengths, weaknesses, opportunities, and threats to the system. RESULTS: In total, 171 health care professionals participated in the different workshops, and 770 others were questioned among 150 health care establishments from 10 health care regions of the country. At the end of this research work, organizational and technical problems were noted at the level of the health information system of Gabon, notably the absence of a judicial framework defining the roles and responsibilities of the different actors of the system, weak data management, a stovepipe information system, several non-interoperable IT applications, and weak completeness rate, at 30%. Among the 770 health care professionals surveyed, 539 (70%) were favorable to a new information system. As for the main assets, we noted the existence of computing equipment and acceptable internet coverage, 31.5% of the health care establishments are connected via cable. CONCLUSION: This research sheds light on the existing health information system and should enable the implementation of a new system.

Molecular analysis of human Papillomavirus detected among women positive for cervical lesions by visual inspection with acetic acid/Lugol's iodine (VIA/VILI) in Libreville, Gabon.

BACKGROUND: The human papillomavirus (HPV) is the causative agent of cervical cancer, which is the leading cancer-related cause of death for women in Sub-Saharan Africa. In 2013, the Gabonese Ministry of Health and the Sylvia Bongo Ondimba Foundation implemented cervical cancer screening programs based on the detection of cancerous lesions by visual inspection with acetic acid and/or Lugol's iodine (VIA/VILI). This pilot study was set up to determine the HPV profile and analyze the nucleotide sequence variation of HPV16 circulating in patients with cervical abnormalities detected by VIA/VILI testing. METHODS: The cervical abnormalities observed upon VIA/VILI were confirmed by liquid-based cytology for all tested women. Nested PCR using the MY09/11 and GP5+/6+ primer sets was used to detect HPVs present in the extracted DNA. HPV genotypes were determined after sequencing of amplicons based on a high-throughput sequencing approach. For isolates of the HPV16 genotype, the E6 gene and the long control region (LCR) were directly sequenced using Sanger method. RESULTS: The study included 87 women who showed a positive VIA/VILI result. Cervical abnormalities were found in 40.23 % of women and 40 % were classified as high-grade lesions. The HPV detection rate was 82.9 % among women with abnormal cytology. Among all the identified high-risk HPV genotypes, HPV16, 18 and 33 were the most frequent. Multiple HPV infections were observed in 42.31 % of HPV-infected women. Analysis of the HPV16 sequence variation in the E6 gene and in the LCR showed that 85.3 and 14.7 % belonged to the African and European lineages, respectively. Among the African branch variants, Af2 was the most frequently identified in this study. CONCLUSION: This study offers the first report of the HPV detection rate and molecular epidemiology among Gabonese women with a positive result in a VIA/VILI screening test. Moreover, data on the HPV16 sequence variation confirm the predominance of African variants in high-grade lesions.

Epidemiological and molecular features of hepatitis B and hepatitis delta virus transmission in a remote rural community in central Africa.

Hepatitis B virus (HBV) and hepatitis delta virus (HDV) occur worldwide and are prevalent in both urban and remote rural communities. In a remote village in Gabon, central Africa, we observed a high prevalence of HBsAg carriage and HDV infection, particularly in children and adolescents. The prevalence of HBsAg differed significantly by gender and age, females being more likely than males to carry the HBsAg during the first 10 years of life, while the prevalence was higher among males than females aged 11-20 years. We also characterised HBV and HDV strains circulating in the village. The principal HBV strains belonged to genotype HBV-E and subgenotype QS-A3. Complete genome analysis revealed for the first time the presence of the HBV-D genotype in Gabon, in the form of an HBV-D/E recombinant. Molecular analysis of HDV strains and their complete genomic characterisation revealed two distinct groups within the dominant HDV clade 8. Molecular analysis of HBV and HDV strains did not reveal vertical transmission within the families studied but rather horizontal, intrafamilial transmission among children aged 0-10 years. Our findings indicate that HBV is transmitted in early childhood by body fluids rather than by sexual contact. Health education adapted to the different age groups might therefore help to reduce HBV transmission. Young children should be vaccinated to control HBV infection in areas of extremely high prevalence.

Genetic diversity of Plasmodium falciparum isolates from Baka Pygmies and their Bantu neighbours in the north of Gabon.

BACKGROUND: There have been many reports on the population genetic structure of Plasmodium falciparum from different endemic regions especially sub-Saharan Africa. However, few studies have been performed on neglected populations, such as the Pygmy populations. In this study, the population genetic structure of P. falciparum was investigated in the Baka Pygmies of Gabon and compared to that observed in neighboring villages composed mostly of Bantu farmers. METHODS: A total of 342 blood samples were collected from 170 Baka Pygmies and 172 Bantus in the north of Gabon (Woleu Ntem Province). Plasmodium infections were characterized by sequencing a portion of the parasite cytochrome b gene. Population genetic structure of P. falciparum in the different villages was analysed using microsatellite markers and genes coding for antigenic proteins (MSP1, MSP2, GLURP, and EBA-175). RESULTS: Overall, prevalence of P. falciparum was around 57 % and no significant difference of prevalence was observed between Pygmies and Bantus. No significant differences of population genetic structure of P. falciparum was found between Pygmy and Bantu people except for one antigen-coding gene, glurp, for which genetic data suggested the existence of a potentially disruptive selection acting on this gene in the two types of populations. The genetic structure of P. falciparum followed a pattern of isolation by distance at the scale of the study. CONCLUSION: The prevalence and genetic diversity of P. falciparum observed in Baka demonstrates a significant transmission of the parasite in this population, and some exchanges of parasites with Bantu neighbours. Despite that, some antigen-coding genes seem to have had a particular evolutionary trajectory in certain Pygmy populations due to specific local human and/or mosquito characteristics.

Clinical forms of chikungunya in Gabon, 2010.

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

No clinical or biological difference between Chikungunya and Dengue Fever during the 2010 Gabonese outbreak.

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

In vitro antiplasmodial activity and cytotoxicity of nine plants traditionally used in Gabon.

AIM OF THE STUDY: As part of a project to identify new compounds active on malarial parasites, we tested the in vitro antiplasmodial activity of nine plants traditionally used to treat malaria symptoms in Haut-Ogooué Province, South-East Gabon. MATERIALS AND METHODS: Dichloromethane and methanolic extracts of each plant were tested for their antiplasmodial activity on two chloroquine-resistant strains of Plasmodium falciparum (FCB and W2), based on lactate dehydrogenase activity. Cytotoxicity was assessed with the MTT test on MRC-5 human diploid embryonic lung cells. RESULTS: The methanolic extract of Staudtia gabonensis and the dichloromethane extract of Adhatoda latibracteata showed high antiplasmodial activity (IC50<1 µg/ml) and low cytotoxicity, with selectivity indexes of about 58.25 and 16.43, respectively. The methanolic extract of Monodora myristica and the dichloromethane extract of Afromomum giganteum also showed promising activity (1

[Reasons for stopping and restarting tuberculosis treatment in Libreville (Gabon)]. / Les causes d'abandon et les motivations d'une reprise de traitement au Centre antituberculeux de Libreville (Gabon).

Tuberculosis is an important public health problem in Gabon, and the DOTS strategy recommended by the World Health Organisation has not been successfully applied. In 2006, 45% of patients abandoned treatment during the first phase. A pilot cross-sectional study was thus conducted from September 1 to November 30, 2006, at the Nkembo Tuberculosis Centre in Libreville, Gabon. Thirty patients with positive microscopy results who returned after having interrupted treatment completed a standardised questionnaire. They were mainly young men: their mean age was 33 years old and the male/female ratio was 2.7. Reasons for having abandoned treatment were a lack of money to pay for it (43%) and an impression that they had been cured (23%). The motivations for resuming treatment were the return of symptoms (73%). The risk of drug resistance requires that the Gabonese government play a greater role in the fight against tuberculosis.

Relationship between in vivo synchronicity of Plasmodium falciparum and allelic diversity.

Plasmodium falciparum cells tend to grow in synchronicity during their cyclic intraerythrocytic development in vivo. Both host and parasite factors appear to be involved in this synchronization. We examined the link between mixed-allelic-family P. falciparum infection and synchronicity in parasitized red blood cells (PRBC) from symptomatic children. The distribution of rings and trophozoites in each PRBC sample was determined by standard microscopy. P. falciparum was genotyped by using a polymerase chain reaction (PCR) targeting three loci (merozoite surface proteins (MSP) 1 and 2, and 175-kD erythrocyte binding antigen (EBA), allowing us to distinguish parasite clones belonging to a single-allelic family (SAF) and those belonging to a mixed-allelic family (MAF). Parasite development was considered synchronous when peripheral blood contained at least 95% of rings or 95% of trophozoites. Parasite development was synchronous in 22 (21.2%) of the 104 children studied. Twenty (90.9%) of these infections were SAF and two (9.1%) were MAF. Rings and trophozoites predominated in respectively 12 (60%) and 8 (40%) SAF infections. Respectively 17.1% and 82.9% of the 82 asynchronous cases corresponded to SAF and MAF infection. Parasite synchronicity was therefore significantly related to single-allelic-family infection (p<2x10(-10)). Twenty different MSP-1 alleles and thirteen different MSP-2 alleles were identified. Only three isolates from patients with SAF infection comprised a single allele or genotype, the other isolates harboring at least two alleles. The mean number of alleles or clones was respectively 3.0 and 10.0 in SAF and MAF infection. These results reflect the allelic diversity of the MSP loci and show that SAF infection can correspond to multiple parasite clones (or genotypes) but, in general, fewer than in MAF infection (p