Determination of the prevalence of Mycoplasma hominis and Ureaplasma species in Bacterial vaginosis patients in association with antibiotic resistance profile in Franceville, Gabon.

BACKGROUND: Genital mycoplasma are only considered pathogenic at a certain level and are often associated with other pathological situations such as bacterial vaginosis (BV). They may lead to infertility as well as other gynaeco-obstetrical and neonatal problems. Despite numerous reported resistances, macrolides are required to treat pregnant women while non-pregnant women are managed with tetracyclines and fluoroquinolones. This study aimed to establish the prevalence and resistance rates of Mycoplasma hominis (Mh) and Ureaplasma spp. (Uu) in BV positive (BV+) women. MATERIAL AND METHODS: Vaginal secretions were collected from women aged 14-56 years consulting for a cytobacteriological examination of the vaginal swab associated with a simultaneous search for genital mycoplasma in the medical analysis laboratory of the Research and Medical Analysis Unit (URAM) of CIRMF in Franceville, Gabon. BV was diagnosed using the Nugent score while genital mycoplasma identification and antibiotic susceptibility testing were performed using the Mycoplasma IST 2 kit. RESULTS: Of the 462 women included in this study, 60.18% (278/462, p = 0.00002) were both BV+ and genital mycoplasma carriers, including 5.19% (24/462) pregnant women. Overall mycoplasma carriage was 33.12% (153/462) for Uu, 1.95% for Mh and 25.11% (116/462) for mixed infections (Uu + Mh). The BV + patients most affected by mycoplasma were those whose age varied from 25 to 35 years with 27.49% (127/462, p = 0.980), those not using condoms with 39.40% (182/462, p = 0.014, OR = 2.35), those non-pregnant but capable of bearing children with 53.90% (249/462, p = 0.967, OR = 1.02). In the overall population, 83.66% and 51.63% of Uu strains were highly resistant to Ciprofloxacin and Azithromycin respectively; 100% and 55.56% of Mh strains were resistant to Azithromycin and Tetracycline respectively; while strong resistance has been observed in mixed infections to Ciprofloxacin (97.41%), Azithromycin (81.90%), Ofloxacin (69.83%) and Tetracycline (68.97%). CONCLUSION: The prevalence of genital mycoplasma infections is very high in women with bacterial vaginosis. Given the numerous emerging resistance rates to most classes of antibiotics available for the treatment of genital mycoplasma infections in our study, it would be advisable for therapeutic prescriptions to be made based on laboratory results.

Acceptability of neonatal sickle cell disease screening among parturient women at the Paul Moukambi Regional Hospital in rural Eastern Gabon, Central Africa.

Neonatal screening and the effective management of sickle cell disease (SCD) are now well established in urban areas in some sub-Saharan African countries. The high rate of sickle cell trait in Koula-Moutou, Gabon, prompted an assessment of the psycho-clinical context of the introduction of neonatal screening in this rural area in eastern Gabon. Interviews were conducted with 215 women from February to June 2016 in Maternity and Maternal Child Protection services at the Paul Moukambi Regional Hospital Center in Koula-Moutou. Few childbearing women knew about SCD (24%), very few (6%) knew their hemoglobin status and only 30% of parturient women authorized sampling for neonatal SCD screening. Young mothers aged 16-28 years (p=0.018) and those who were educated (p=0.002) were more likely to authorize neonatal blood screening. There was no association between acceptance of blood sampling and knowledge of SCD or the parturient woman's hemoglobin status. The barriers to acceptance for SCD neonatal diagnosis are related to the education and culture rather than the knowledge of this disease. Introduction of diagnosis in rural areas requires a team comprising a psychosocial worker and health workers known to the rural population, to remove inhibitions related to blood collection from newborn infants.

Decline in the seroprevalence of syphilis markers among first-time blood donors in Libreville (Gabon) between 2004 and 2016.

BACKGROUND: Very few studies have been conducted on the seroprevalence of syphilis in Gabon. According to the World Health Organization, the average seroprevalence of syphilis has declined from 5.5 to 1.1% in Central Africa. The aim of this study was to test the hypothesis that syphilis decreased in Gabon between 2004 and 2016 and to identify factors involved in this pattern by testing a large sample of first-time blood donors in the capital Libreville. METHODS: The detection of Treponema pallidum was done using a Rapid Plasma Reagin test (RPR) and confirmed by an ELISA test using the Biorad Syphilis Total Antibody EIA II kit or BioMerieux Trepanostika TP recombinant. Assays were performed by dedicated technicians according to manufacturers' recommendations and following the laboratory standard operating procedures. Test results were manually transferred into the laboratory Excel files and hand-written in the laboratory logbook for syphilis testing. Logistic regression was used to assess the impact of sociodemographic characteristics on syphilis marker seroprevalence in both univariate and multivariable analysis. Odds ratios (OR) and 95% confidence intervals were calculated. RESULTS: The seroprevalence of syphilis markers was 8.4% (95% CI = 7.9-8.9) in 2004 and 2.4% (95% CI = 2.1-2.7) in 2016. The difference was significant [OR = 3.78; 95% CI (3.26-4.38); P < 0.001]. The decrease in syphilis seroprevalence was significant in both women and men and in each age group in univariate analysis. In multivariable analysis, controlling for all sociodemographic factors, the decrease in syphilis seroprevalence from 2004 to 2016 remained significant (OR = 3.29; 95% CI = 2.88-3.88, P < 0.001). The seroprevalence of syphilis decreased significantly in men compared to women and young donors compared to donors aged ≥36 years. CONCLUSIONS: This study shows a significant decline in syphilis seroprevalence in first-time blood donors in Libreville, Gabon. Government actions, including multiple HIV prevention activities, are a likely part of this decline.

Assessment of rapid diagnostic tests and fourth-generation Enzyme-Linked Immunosorbent Assays in the screening of Human Immunodeficiency and Hepatitis B virus infections among first-time blood donors in Libreville (Gabon).

BACKGROUND: Blood transfusion is a pathway for the transmission of blood-borne pathogens such as human immunodeficiency virus (HIV) and hepatitis B virus (HBV) from donors to recipients in most countries in sub-Saharan Africa, including Gabon. The study aimed to compare the performance of four rapid diagnostic tests (RDTs: Alere DETERMINE, BIOSYNEX Exacto Pro HIV, MEDIFF HIV 1&2, and BIOSYNEX IMMUNOQUICK HBsAg) with results of 4th-generation immunoenzymatic assays COBAS 6000 e601 and EVOLIS BioRad for the detection of HIV and hepatitis B surface antigen (HBsAg) in blood donors in Libreville, Gabon. METHODS: Reactive and nonreactive blood samples for HIV and HBsAg were selected using fourth-generation ELISA COBAS 6000 e601 and EVOLIS BioRad. The sensitivities of RDTs were calculated using Epi Info version 6.04dfr (CDC, Atlanta, USA). RESULTS: Sensitivities for the detection of HIV in blood donors were 90.9% for Alere DETERMINE, 81.8% for BIOSYNEX Exacto Pro HIV, and 81.8% for MEDIFF HIV 1&2 Serum/sang Total Cassette compared with COBAS 6000 e601. The sensitivity of Alere DETERMINE compared to the semi-automated ELISA Bio-Rad for HIV detection was 65.6%. The sensitivity of BIOSYNEX IMMUNOQUICK HBsAg compared to ELISA tests for the detection of HBsAg was 78.0%. The specificity of all RDTs for the detection of HIV and HBsAg was 100%. CONCLUSION: Alere DETERMINE HIV-1/2, MEDIFF HIV 1&2 Serum/sang Total Cassette, BIOSYNEX Exacto Pro HIV, and BIOSYNEX IMMUNOQUICK HBsAg are not recommended for determining whether donors qualify to donate blood because of their low sensitivity for the detection of HIV antibodies and HBsAg in blood donors in Gabon.

Haematological values in steady-state sickle cell anaemia patients and matched heamoglobin AA Controls in a Rural Area of Eastern Gabon.

BACKGROUND: In Gabon, universal neonatal screening of sickle cell disease is not carried out in rural areas, often leading to late detection of the disease. However, complete blood counts are available in rural areas. MATERIALS AND METHODS: We evaluated the haematological parameters of 45 homozygous steady-state sickle cell anaemia (SCA) patients and compared them with 45 sex- and age-matched Haemoglobin AA controls in Koula-Moutou, a rural area in Eastern Gabon. RESULTS: Homozygous SCA patients had low erythrocyte values (red blood cells: 2.50 × 1012/L, haemoglobin: 7.20 g/dL and haematocrit: 20.70%) and high leucocyte values (white blood cells: 14.40 × 109/L, lymphocytes: 5.24 × 109/L and monocytes: 1.60 × 109/L). Most of the SCA patients had severe anaemia (67%), normochromia (76%), lymphocytosis (73%) and monocytosis (84%). A haemoglobin level of < 8.5 g/dL together with a leucocyte level above 9.5 × 109 cells/L was used as screening test to detect homozygous SCA patients, with sensitivity of 84.4% and specificity of 97.8%. CONCLUSION: The values for erythrocyte and leucocyte cell lines of SCA patients in steady state are clearly different from those of the matched HbA/A controls. This makes it possible to set up a tool to detect SCA based on the haemogram in a rural area that does not possess haemoglobin electrophoresis. This tool could be used by healthcare workers in the absence of universal newborn screening for SCA.

Genotyping of CCR5 gene, CCR2b and SDF1 variants related to HIV-1 infection in Gabonese subjects.

OBJECTIVE: Given the magnitude of the HIV epidemic infection, many viral and human factors were analyzed, and the most decisive was the variant CCR5-Δ32. The presence of a low HIV prevalence (1.8%) in Gabon in the 1990s, compared to neighboring countries, represents a paradox that led us to search for viral and human genetic variants in this country. In this study, only variants of coreceptors and chemokines were investigated. METHODS: Variants of the coding region of the CCR5 gene were analyzed by denaturing gradient gel electrophoresis, and then variants of SDF1 and CCR2b were determined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Four rare variants of the CCR5 coreceptor were found, while CCR5-Δ32 and CCR5m303 variants were not found. No association with CCR2b-V64I (17%) and SDF1-3'A (2%) variants was determined in relation to HIV-1 infection in Gabonese patients. CONCLUSION: The paradox of HIV seroprevalence in Gabon, which ended in the 2000s, was not caused by human genetic variants but rather by environmental factors.

Decrease on malaria clinical cases from 2017 to 2019 in Franceville, Southeast Gabon, Central Africa.

Background: In Gabon, malaria remains a major public health problem. All malaria cases with axillary temperature ≥ 37.5°C with a parasites density ≥ 1200/µL are serious cases and must be treated as a medical emergency. Thus, early diagnosis is essential for successful treatment. Because of the impact of malaria on the population, the surveillance of malaria infections in hospitals is urgently needed. The aim of this study was to to assess of clinical cases of malaria in a private health structure in Franceville between 2017 and 2019. Methods: For that, we conducted a retrospective study using data on malaria cases recorded in a private medical analysis laboratory in Franceville, southeast Gabon. Malaria was diagnosed in this laboratory using a Rapid Diagnostic Test and confirmed by microscopic analysis. Results: Analysis of 2518 patient forms revealed an increase in malaria prevalence in Franceville between 2017-2019. The global clinical cases was 26.1% (658/2015). Children under 5 years (44.0%) and patients aged 5-14 years (40.1%) were more affected than patients aged ≥15 years (18.8%, P=0.0001). Malaria infection was also significantly dependent on season and gender. We observed at least three Plasmodium species and the predominant Plasmodium species was P. falciparum 80.0%, followed by P. ovale (19.5%) and P. malariae (17.8%). Conclusion: Our study showed that malaria remains a public health priority for the population of Franceville and that the prevalence of clinical cases of malaria at the laboratory decrease between 2017 and 2019. Our results highlight the need for strategies to control malaria in Franceville, adapted to epidemiological contexts and environmental constraint.

Human T-Lymphotropic virus type 1 and human immunodeficiency virus co-infection in rural Gabon.

INTRODUCTION: Human T-cell lymphotrophic virus type-1 (HTLV-1) and human immunodeficiency virus (HIV-1) co-infection occur in many populations. People living with HIV-1 and infected with HTLV-1 seem more likely to progress rapidly towards AIDS. Both HTLV-1 and HIV-1 are endemic in Gabon (Central Africa). We investigated HTLV-1 and HIV-1 co-infection in the Haut-Ogooué province, and assessed factors that may favor the rapid evolution and progression to AIDS in co-infected patients. METHODS: Plasma samples from HTLV-1 patients were tested using ELISA, and positive samples were then tested by western blot assay (WB). We used the polymerase chain reaction to detect HTLV-1 Tax/Rex genes using DNA extracted from the buffy coat of ELISA-positives samples. RESULTS: We recruited 299 individuals (mean age 46 years) including 90 (30%) men and 209 (70%) women, all of whom are under treatment at the Ambulatory Treatment Centre of the province. Of these, 45 were ELISA HTLV-1/2 seropositive. According to WB criteria, 21 of 45 were confirmed positive: 20 were HTLV-1 (44%), 1 was HTLV-1/2 (2%), 2 were indeterminate (4%) and 22 were seronegative (49%). PCR results showed that 23 individuals were positive for the Tax/Rex region. Considering both serological and molecular assays, the prevalence of HTLV-1 infection was estimated at 7.7%. Being a woman and increasing age were found to be independent risk factors for co-infection. Mean CD4+ cell counts were higher in HTLV-1/HIV-1 co-infected (578.1 (± 340.8) cells/mm3) than in HIV-1 mono-infected (481.0 (± 299.0) cells/mm3) Individuals. Similarly, the mean HIV-1 viral load was Log 3.0 (± 1.6) copies/ml in mono-infected and Log 2.3 (± 0.7) copies/ml in coinfected individuals. CONCLUSION: We described an overall high prevalence of HTLV-1/HIV-1 co-infection in Gabon. Our findings stress the need of strategies to prevent and manage these co-infections.

Ethnic differences in CD1E, but not CD1A, gene polymorphisms between Sub-Saharan Africans, West Asians and Europeans.

The five closely linked CD1A-E genes encode the human CD1 family of proteins. Few studies of the allele frequencies of these genes in African populations have been published so far. This study aimed to genotype CD1A and CD1E variants and to compare their frequencies in Sub-Saharan Africans from Gabon and Ivory Coast, and Non-Africans from Syria and France. A restriction analysis of DNA fragments generated by PCR was performed to detect CD1A and CD1E alleles in 105 subjects from Gabon, 169 subjects from Ivory Coast, 107 subjects from Syria and 181 subjects from France. The frequencies of the CD1E*02 allele were high among Sub-Saharan Africans (87%) and low in West Asians (44%) and Europeans (36%), whereas the contrary was obtained for the CD1E*01 allele (7%, 55% and 64% respectively). Frequencies of CD1A alleles were similar between all groups, the CD1A*02 allele was most prevalent (91%). The high frequency of the CD1E*02 allele in Sub-Saharan Africans suggest that future work should investigate the relationship between CD1 polymorphism and infectious diseases.

Trends of blood-borne infectious diseases in a rural blood donation center of southeast Gabon (Koula-Moutou).

INTRODUCTION: Blood-borne pathogens such as human immunodeficiency virus (HIV), hepatitis B and C (HBV and HCV) viruses and Treponema pallidum remain a major public health problem in sub-Saharan Africa. The purpose of this study was to assess the frequency and clinical implications of HIV, HBV, HCV and Treponema pallidum markers in blood donors in a rural area of Southeast Gabon (Koula-Moutou) from 2012 to 2017. METHODS: Hepatitis B surface antigen (HBsAg), anti-HIV, anti-HCV and anti-Treponema pallidum antibodies were screened using rapid diagnostic tests (RDTs). RESULTS: Of a total of 5,706 blood donors, 1,054 (18.5%) were seropositive for at least one infectious marker and 59 (5.6%) had serologic evidence of multiple infections. The overall seroprevalence of HIV, HBsAg, HCV, and syphilis was 3.1%; 5.9%; 6.2% and 3.3%, respectively. HIV, syphilis and HCV distributions were associated with neither the sex nor the age of the donors. Only HBsAg seroprevalence was significantly higher in donors of the age group 26-35 years old compared to donors of the age group 36-45 years (OR = 1.43 (95% CI: 1.01-2.04), P = 0.045). There was a significant increase in the frequencies of HIV and syphilis and a regression of HBsAg and HCV among blood donors. CONCLUSION: This study presents the epidemiology of the main pathogens detected in blood donors in a rural area in Gabon. We found that the overall distribution of transfusion transmitted infectious diseases were lower than those observed in the general population but could be underestimated due to the use of RDTs in the screening process of the blood donations.

Prevalent hepatitis B surface antigen among first-time blood donors in Gabon.

Despite chronic Hepatitis B virus (HBV) infection being the main cause of younger-onset complex liver disease including cirrhosis and hepatocellular carcinoma (HCC) in Africa, very little is known regarding the seroprevalence of HBV in the Gabonese general population. This investigation aimed to provide strong epidemiological data and risk factors associated with HBV infection in first-time blood donors representative of the urban adult population. The screening of HBsAg was carried out using 4th generation ELISA kits. The overall seroprevalence of HBsAg was 7.28%. The frequency of HBsAg was differential and marked by annual variations in blood donors from 2009 to 2016. Seroprevalence was 2-fold higher among males versus females (OR = 1.90 (95% CI: 1.75-2.06), P<0.001). HBsAg seroprevalence was significantly higher in donors of the age group 25-35 years old compared to donors of the age group <18 years (OR = 1.64 (95% CI: 1.03-2.60), P = 0.04). The seroprevalence of HBsAg in family/replacement donors (FRD) was significantly higher than that of voluntary non-remunerated donors (VNRD) (OR = 0.88 (95% CI: 0.83-0.94), P <0.001). The simultaneous comparison of HBsAg seroprevalence with blood donation type, gender and age showed that the higher prevalence in FRD was significant only in males between 18 and 45 years and in females between 25 and 34 years of age. This study confirms the high endemicity of HBV in Gabon while identifying the most infected age groups for both men and women.

Homozygosity for the CD1E*02 allele is associated with a resistance to Plasmodium falciparum malaria infection in Gabonese school children.

OBJECTIVE: To explore the possible association between polymorphisms in CD1 genes and both asymptomatic and mild Plasmodium falciparum infection. METHODS: Two clusters of 85 school children, from the village of Dienga (Gabon) were investigated. The first group was analysed for the prevalence and the multiplicity of asymptomatic P. falciparum infection, whereas the second group was screened for the frequency of malarial attacks. RESULTS: Our findings showed that homozygosity for the CD1E*02 allele was associated with a low frequency of malarial attacks. Furthermore, a strong association between CD1E*02 homozygotes and the resistance to multiple malarial attacks was identified. The CD1A*01 allele showed a weak association with a small number of malarial attacks. CONCLUSION: Our results suggest a possible role of CD1E polymorphisms in malaria protection among school children and that CD1e molecules are involved in anti-malarial immunity.

Patterns and risk factors of birth defects in rural areas of south-eastern Gabon.

Within the context of high neonatal mortality in sub-Saharan Africa, a retrospective study was conducted on the prevalence of congenital malformations and the association between maternal risk factors and birth defects in rural populations of south-eastern Gabon. Two populations were studied: a group of 3500 births recorded in rural area (Koula-Moutou) and a second group of 4212 births in a semi-rural area (Franceville) in Gabon. Our data showed an increasing prevalence in congenital anomalies from rural to urban areas (P < 0.001). Maternal risk factors such as age > 35 years, multiparity and employment status were significantly associated with the levels of stillbirth. Together with abortions and stillbirths, congenital malformations require strong monitoring in rural and urban areas of sub-Saharan Africa.

Haemoglobin F, A2, and S levels in subjects with or without sickle cell trait in south-eastern Gabon.

BACKGROUND: Infant mortality due to sickle cell disease in sub-Saharan Africa is high, necessitating a better understanding of the modulating factors of the disease in this region. METHODS: We assessed the hereditary persistence of foetal haemoglobin and α-thalassemia. We diagnosed 787 subjects, with or without sickle cell trait, by capillary electrophoresis in the Medical Diagnostic Laboratory of the CIRMF (Franceville, Gabon). RESULTS: Heterocellular and pancellular forms of hereditary persistence of foetal haemoglobin occurred at low rates of 10.9 and 2.3%, respectively. The distribution of HbS levels in individuals with sickle cell trait was trimodal, showing a high percentage (52.4%) of heterozygous subjects with α-thalassemia. The distribution of HbA2 levels was bimodal in individuals without sickle cell trait, estimated to be comprised of 12 and 15% of α and ß-thalassemic heterozygous subjects, respectively. CONCLUSIONS: In sub-Saharan Africa, α-thalassemia is a far more prevalent modulating factor than hereditary persistence of foetal haemoglobin. Our study highlights the need for further investigation of thalassemia, haemoglobinopathies that are neglected in sub-Saharan Africa.

Human genetic polymorphisms and asymptomatic Plasmodium falciparum malaria in Gabonese schoolchildren.

Several studies have focused their attention on the relationship between host genetic factors and susceptibility/resistance to severe malaria. However, there is a paucity of information concerning the role of host genetic factors in asymptomatic malaria, a form of low-grade Plasmodium falciparum infection without clinical symptoms. We investigated in this study the potential relationship between the host (human) genetic polymorphisms (glucose-6-phosphate dehydrogenase [G6PD], mannose binding lectin [MBL], tumor necrosis factor alpha [TNFalpha](-308) and (-238), and nitric oxide synthase 2 [NOS2](-954)) and the prevalence and profile of asymptomatic P. falciparum infection in 158 Gabonese schoolchildren. We found that G6PD A- heterozygous females (18 of 74) have a low prevalence of asymptomatic malaria (38.9% versus 67.3%; P = 0.03, by chi-square test). Children heterozygous for TNFalpha(-238) (25 of 156) carry high number of diverse infecting parasite genotypes (2.5 versus 1.99; variance F = 3.05). No statistically significant association was found between MBL, TNFalpha(-308), or NOS2 polymorphisms and asymptomatic malaria. Upon combining our data on asymptomatic forms with those from the literature for others forms, we conclude that G6PD A- heterozygous females are protected against all forms of P. falciparum malaria, and that the TNFalpha(-238A) allele confers protection against clinical malaria.

Origin of Hb A2' (Hb B2) [delta16(A13)Gly --> Arg (GGC --> CGC)].

On a field trip to the Dogon country (le Pays Dogon) in central Mali, we detected a high frequency of the Hb A2 abnormality, reaching higher numbers among blacksmiths (up to 12.4%) living in the same villages. In this report, by direct nucleotide sequencing and employing a polymerase chain reaction-restriction fragment length polymorphism approach, we show that the Hb A2 variant observed in the Dogon population is indeed Hb A2', also called Hb B2, and that in all of the cases the abnormal delta-globin gene is linked to a unique haplotype. The same haplotype was found linked to Hb A2' in the Herero population belonging to the South African Bantu-speaking Blacks from Namibia. Although the unique origin of this mutation in Africa is a possibility, a recurrent mutational event cannot be excluded because the linked beta cluster haplotype is one of the two major haplotypes found in all African populations. A study of populations from other regions of Africa is required to clarify this issue.