Risk Factors Associated with Opportunistic Infections among People Living with HIV/AIDS and Receiving an Antiretroviral Therapy in Gabon, Central Africa.

The Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) is still one of the main causes of death in sub-Saharan Africa. Antiretroviral therapies (ARTs) have significantly improved the health conditions of people living with HIV/AIDS (PLWHA). Consequently, a significant drop in morbidity and mortality, along with a reduced incidence of opportunistic infections (OIs), has been observed. However, certain atypical and biological profiles emerge in ART patients post-examination. The objective of this study was to identify the risk factors that contributed to the onset of OIs in HIV patients undergoing ART in Gabon. Epidemiological and biological data were obtained from medical records (2017 to 2019) found at the outpatient treatment centre (CTA) of Franceville in Gabon. Samples for blood count, CD4, and viral load analysis at CIRMF were collected from PLWHA suffering from other pathogen-induced conditions. A survey was carried out and data were analysed using Rstudio 4.0.2 and Excel 2007 software. Biological and socio-demographic characteristics were examined concerning OIs through both a univariate analysis via Fisher's exact tests or chi2 (χ2), and a multivariate analysis via logistic regression. Out of the 300 participants initially selected, 223 were included in the study, including 154 (69.05%) women and 69 (30.95%) men. The mean age was 40 (38.6; 41.85), with individuals ranging from 2 to 77 years old. The study cohort was classified into five age groups (2 to 12, 20 to 29, 30 to 39, 40 to 49, and 50 to 77 years old), among which the groups aged 30 to 39 and 40 to 49 emerged as the largest, comprising 68 (30.5%) and 75 (33.6%) participants, respectively. It was noted that 57.9% of PLWHA had developed OIs and three subgroups were distinguished, with parasitic, viral, and bacterial infections present in 18%, 39.7%, and 55.4% of cases, respectively. There was a correlation between being male and having a low CD4 T-cell count and the onset of OIs. The study revealed a high overall prevalence of OIs, and extending the study to other regions of Gabon would yield a better understanding of the risk factors associated with the onset of these infections.

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.

Broad Range of Hepatitis B Virus (HBV) Patterns, Dual Circulation of Quasi-Subgenotype A3 and HBV/E and Heterogeneous HBV Mutations in HIV-Positive Patients in Gabon.

Integrated data on hepatitis B virus (HBV) patterns, HBV genotypes and mutations are lacking in human immunodeficiency virus type 1 (HIV-1) co-infected patients from Africa. This survey was conducted in 2010-2013 among 762 HIV-1-positive adults from Gabon who were predominantly treated with 3TC-based antiretroviral treatment. HBV patterns were identified using immunoassays detecting total antibody to hepatitis B core antigen (HBcAb), hepatitis B surface antigen (HBsAg), IgM HBcAb, hepatitis B e antigen (HBeAg), antibody to HBsAg (HBsAb) and an in-house real-time PCR test for HBV DNA quantification. Occult hepatitis B (OBI) was defined by the presence of isolated anti-HBc with detectable serum HBV DNA. HBV genotypes and HBV mutations were analyzed by PCR-direct sequencing method. Seventy-one (9.3%) patients tested positive for HBsAg, including one with acute hepatitis B (0.1%; 95% CI, 0.0%-0.2%), nine with HBeAg-positive chronic hepatitis B (CHB) (1.2%; 95% CI, 0.6%-2.2%), 16 with HBeAg-negative CHB (2.1%; 95% CI, 1.2%-3.3%) and 45 inactive HBV carriers (5.9%; 95% CI, 4.4%-7.8%). Sixty-one (8.0%; 95% CI, 6.2%-10.1%) patients showed OBI. Treated patients showed similar HBV DNA levels to those obtained in untreated patients, regardless of HBV patterns. Around 15.0% of OBI patients showed high (>1,000 UI/mL) viremia. The mutation M204V/I conferring resistance to 3TC was more common in HBV/A (47.4%) than in HBV/E isolates (0%) (P = .04). Our findings encouraged clinicians to promote HBV vaccination in patients with no exposure to HBV and to switch 3TC to universal TDF in those with CHB.

Usefulness of a fourth generation ELISA assay for the reliable identification of HCV infection in HIV-positive adults from Gabon (Central Africa).

BACKGROUND/OBJECTIVES: Guidelines for optimized HCV screening are urgently required in Africa, especially for patients infected with HIV, who sometimes show false positive or false negative reactivity in anti-HCV antibody assays. Here, we assessed the usefulness of a fourth-generation HCV Ag-Ab ELISA for the identification of active HCV infection in HIV-positive patients. METHODS: This cross-sectional study was conducted between 03/2010 and 01/2013 and included 762 Gabonese HIV-positive adult patients. The results of ELISA (Monolisa HCV Ag-Ab ULTRA, Bio-Rad) were compared with those obtained by RT-PCR (gold standard). The optimal ELISA signal-to-cutoff (S/CO) ratio to identify patients with active hepatitis C (positive HCV RNA) was determined. Specimens were further tested by the INNO-LIA HCV Score assay (Innogenetics) and the Architect HCV Ag kit (Abbott) to define the best diagnostic strategy. RESULTS: Sixty-seven patients tested positive for HCV (S/CO ratio ≥ 1) by ELISA. Of these, 47 (70.1%) tested positive for HCV RNA. The optimal S/CO associated with active HCV infection was 1.7. At this threshold, the sensitivity of ELISA was 97.9% (95% confidence interval (CI) 90.0-99.9%), its specificity was 91.3% (95% CI 85.0-95.5%), and HCV seroprevalence rate was 7.3% (56/762) (95% CI 5.6-9.4%). Among 57 HCV-seropositive patients with available INNO-LIA results, false reactivity was identified in 14 (24.6%), resolved HCV infection in two (3.5%), possible acute HCV infections in nine (15.8%) and likely chronic HCV infections in 32 (56.1%) patients. HCV core Ag was undetectable in 14/15 (93.3%) specimens that tested negative for HCV RNA whereas it was quantified in 34 (out of 39, 87.2%) samples that tested positive for HCV RNA. CONCLUSIONS: Our study provides comprehensive guidance for HCV testing in Gabon, and will help greatly clinicians to improve case definitions for both the notification and surveillance of HCV in patients co-infected with HIV.

Significant impact of non-B HIV-1 variants genetic diversity in Gabon on plasma HIV-1 RNA quantitation.

Evaluations of HIV-1 RNA viral load assays are lacking in Central Africa. The main objective of our study was to assess the reliability of HIV-1 RNA results obtained with three different assays for samples collected in Gabon. A total of 137 plasma specimens were assessed for HIV-1 RNA using the Abbott RealTime HIV-1® and Nuclisens HIV-1 EasyQ® version 2.0 assays. It included HIV-1 non-B samples (n = 113) representing six subtypes, 10 CRFs and 18 URFs from patients infected with HIV-1 and treated with antiretrovirals that were found HIV-1 RNA positive (≥300 copies/ml) with the Generic HIV viral load® assay; and samples (n = 24) from untreated individuals infected with HIV-1 but showing undetectable (<300 copies/ml) results with the Biocentric kit. For samples found positive with the Generic HIV viral load® test, correlation coefficients obtained between the three techniques were relatively low (R = 0.65 between Generic HIV viral load® and Abbott RealTime HIV-1®, 0.50 between Generic HIV viral load® and Nuclisens HIV-1 EasyQ®, and 0.66 between Abbott RealTime HIV-1® and Nuclisens HIV-1 EasyQ®). Discrepancies by at least one log10 were obtained for 19.6%, 33.7%, and 20% of samples, respectively, irrespective of genotype. Most of samples (22/24) from untreated study patients, found negative with the Biocentric kit, were also found negative with the two other techniques. In Central Africa, HIV-1 genetic diversity remains challenging for viral load testing. Further studies are required in the same area to confirm the presence of HIV-1 strains that are not amplified with at least two different viral load assays.

Short communication: high natural polymorphism in the gag gene cleavage sites of non-B HIV type 1 isolates from Gabon.

The main goal of the present study was to determine the frequency of substitutions in the cleavage sites (CS) of gag gene among non-B HIV-1 isolates from Gabon. Fifty plasma specimens, collected in 2010-2011, from HIV-1-infected patients failing first-line antiretroviral (ARV) regimens (constituted of two nucleoside reverse transcriptase inhibitors+one nonnucleoside reverse transcriptase inhibitor) (n=38) and from HIV-1-infected individuals untreated with ARV (n=12) were analyzed in the gag and gag-pol cleavage sites. Compared to HXB2 reference sequence, the total median number of substitutions in gag and gag-pol CS was 10 (range, 5-18). The cleavage site p2/NC was the most variable of the four gag CS with 100% (50/50) isolates carrying at least 1 substitution (range, 1-9). The two gag-pol TFP/p6pol and p6pol/PR CS sites were also highly variable (at least one substitution, 50/50, 100% in both cases). Substitutions at position G381 (p2/NC), L449 (p1/p6gag), and K444 (TFP/p6pol) were significantly more frequent in CRF02_AG strains, compared to other non-B strains (30.4% vs. 3.7%, p=0.03; 87.0% vs. 59.3%, p=0.03; and 91.3% vs. 59.3%, p=0.01, respectively). Other non-B subtypes were significantly more likely to harbor substitutions at position N487 (p6pol) (70.4%) than CRF02_AG (39.1%) (p=0.02). In Gabon, gag and gag-pol cleavage sites were highly polymorphic in protease inhibitor-naive patients harboring non-B HIV-1 strains. In sub-Saharan Africa, further studies are definitively required to better understand the impact of gag mutations among subjects receiving second-line LPV/r-containing regimens (monotherapy or triple combinations).

HIV type-1 group O infection in Gabon: low prevalence rate but circulation of genetically diverse and drug-resistant HIV type-1 group O strains.

The goals of this study conducted in Gabon were to determine the prevalence rate of HIV-1 group O (HIV-1/O) infections and to characterize the genetic diversity of HIV-1/O strains as well as implications on antiretroviral (ARV) drug resistance. During 2010-2011, 1,176 samples from HIV-positive subjects were tested at the CIRMF (Centre International de Recherches Médicales de Franceville) retrovirology laboratory using an in-house serotyping assay. Plasma HIV-1/O RNA viral loads (VL) were determined using the Abbott RealTime HIV-1 assay. After full genome sequencing, drug resistance patterns were analyzed using two different algorithms (Agence Nationale de Recherches sur le SIDA et les hépatites virales and Stanford). Overall, four subjects (0.34%) were diagnosed as HIV-1/O infected. One subject, untreated by ARVs, died 2 months after HIV-1/O diagnosis. One was lost to follow-up. Two additional patients, treated with nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens, showed CD4 counts <200/mm(3) and VL results of 101,000 and 10,050 cp/ml. After full-length genome sequencing of these two strains, we found a wide range of natural polymorphism in the protease (≥15 substitutions) and gp41 (N42D mutation) genes, as well as in the gag and gag-pol cleavage sites. No resistance mutation was detected in the integrase gene. These two strains harbored the Y181C mutation making them resistant to NNRTIs. M41L, M184V, and T215Y mutations were also found for one strain, making it resistant to all NRTIs by the Stanford algorithm. Even if HIV-1/O infection is low in Gabon, an accurate diagnosis and a reliable virological follow-up are required in Central Africa to optimize ARV treatments of HIV-1/O-infected patients.

Virological failure rates and HIV-1 drug resistance patterns in patients on first-line antiretroviral treatment in semirural and rural Gabon.

INTRODUCTION: As antiretroviral treatment (ART) continues to expand in resource-limited countries, the emergence of HIV drug resistance mutations (DRMs) is challenging in these settings. In Gabon (central Africa), no study has yet reported the virological effectiveness of initial ART given through routine HIV care. METHODS: Following the World Health Organization (WHO) recommendations, a cross-sectional study with a one-time HIV-1 RNA viral load (VL) measurement was conducted in Gabon to assess virological failure (VF) defined by a VL result ≥1000 copies/ml and DRMs among adult patients living with non-B HIV-1 strains and receiving first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy for at least 12 months. Risk factors associated with VF and DRMs were assessed. RESULTS: Between March 2010 and March 2011, a total of 375 patients were consecutively enrolled from two decentralized (one semirural and one rural) HIV care centres. Median time on ART was 33.6 months (range, 12-107). Overall, the rate of VF was 41.3% (36.4-46.4). Among viremic patients, 56.7% (80/141) had at least one DRM and 37.6% had dual-class resistance to nucleoside reverse transcriptase inhibitors (NRTIs) and NNRTIs. The most frequent DRMs were K103N/S (46.1%) and M184V/I (37.6%). Thymidine analogue mutations were found in 10.6%. Independent risk factors associated with VF were being followed up at the semirural centre (P=0.033), having experienced unstructured treatment interruptions (P=0.0044), and having low CD4+ counts at enrolment (P<0.0001). A longer time on ART (P=0.0008) and being followed up at the rural centre (P=0.021) were risk factors for DRMs. CONCLUSIONS: This is the first study conducted in Gabon providing VF rates and DRM patterns in adult patients receiving first-line ART. In sub-Saharan Africa, where NNRTI-based regimens are recommended as the standard for first-line ART, strengthening virological monitoring together with preventing unplanned treatment interruptions are a global public health priority.

Suitability of an open automated nucleic acid extractor for high-throughput plasma HIV-1 RNA quantitation in Gabon (Central Africa).

Nucleic acid extraction using the open automated EZ1 (Qiagen) instrument, in combination with the Generic HIV Viral Load assay, gave highly concordant HIV-1 RNA viral load results among 181 Gabonese subjects infected with HIV-1, compared to those obtained when performing a manual extraction. Since people living with HIV-1 are being treated with antiretrovirals in Gabon, this automated extraction technique represents an excellent technical method for high-throughput monitoring of HIV-1 RNA viral load.