Bacteriology-Virology

We report the results of a pilot open-label trial of a tenofovir (TDF)/emtricitabine (FTC)/efavirenz (EFV) combination conducted in Dakar, Senegal. Forty HIV-1-infected patients, naive of antiretroviral treatment and without active opportunistic disease, were included and followed through 96 weeks. At weeks 48 and 96, respectively, 82.5% and 85% of patients had HIV-1 RNA <400 copies/mL (72.5% and 77.5% with HIV-1 RNA <50 copies/mL). Between baseline and week 96, the mean (SD) CD4 count increased from 126 (102) to 338 (155) cells/mm3. The mean (SD) creatinine clearance decreased from 92 (36) to 73 (19) mL/min (P = .001). Treatment adherence was at least 94% at all scheduled visits. The efficacy and tolerability of a TDF/FTC/EFV combination were high and similar to those observed in Northern countries. This drug combination can be recommended in limited-resource countries, as did the World Health Organization (WHO) and should be made readily available as a fixed-dose combination.

Background: In Senegal in 2015, an estimated 4800 children were living with HIV, with 1200 receiving ARV treatment, of whom half had follow-up care in decentralized sites outside Dakar. However, until now no studies have determined the efficacy of pediatric treatment in decentralized settings, even though the emergence of viral resistance, particularly among children in Africa, is a well-known phenomenon. This study aimed to assess the virological status of HIV-infected children in all decentralized facilities to help improve access to quality care. Methods: A cross-sectional epidemiological and virological study was conducted in all of Senegal's regions, except Dakar, between March and June 2015 and sought to include all HIV-infected children and adolescents (0-19 years), treated or not with ARVs. Socio-demographic and clinical data and a blood sample on blotting paper were collected for children from treatment sites. Samples were routed on public transportation, assisted by a network of community health workers. A viral load (VL) assay was performed for each child, followed by genotyping when it exceeded 1000 copies/mL (3 log 10). Results: Of the 851 identified children, 666 (78%) were enrolled in the study. Half of the children were girls, and the average age was 8 years (6 months-19 years). Most of the children (96.7%) were infected with HIV-1, and 90% were treated with ART, primarily with AZT + 3TC + NVP/EFV therapeutic regimen. The median duration of time on ART was 21 months (1-129). VL was measured for 2% of children before this study. Almost two-thirds (64%) of the children are experiencing virological failure. Among them, there was resistance to at least one drug for 86.5% of cases. Also, 25% children presented resistance to one drug and 40% to two out of three. For nearly one-third of the children presenting resistance, none of the three drugs of the treatment was active. Factors associated with virological failure were male sex, follow-up by a generalist rather than a specialist, and treatment interruptions. Conclusions: We observed a high level of virological failure and a high percentage of viral resistance among children receiving health care in decentralized facilities in Senegal.

Background To improve the care and treatment of HIV-exposed children, early infant diagnosis (EID) using dried blood spot (DBS) sampling has been performed in Senegal since 2007, making molecular diagnosis accessible for patients living in decentralized settings. This study aimed to determine the evolution of the HIV transmission rate in children from 2008 to 2015 and to analyze associated factors, particularly the mother's treatment status and/or child's prophylaxis status and the feeding mode. Methods The data were analyzed using EID reports from the reference laboratory. Information related to sociodemographic characteristics, HIV profiles, the mother's treatment status, the child's prophylaxis status, and the feeding mode was included. Descriptive statistics were calculated, and bivariate and multivariate logistic regression analyses were performed.

Introduction: Chlamydia trachomatis and Neisseria gonorrhoeae are the most common causes of sexually transmitted disease in Senegal and worldwide. Molecular techniques have become the standard for their detection, and due to the frequency of co-infections, these tests can detect both agents and can be used on urine samples, vaginal swabs, or endocervical samples. In developing countries, the use of these molecular techniques is very limited and there is a need for evaluations of these techniques to be done. Methodology: A total of 181 samples were tested with the Abbott RealTime CT/NG assay and compared with the Roche Cobas Amplicor CT/NG assay. Specimens were collected from the key population of men having sex with men (urine, n = 60), female sex workers (genital swabs, n = 60) and from women visiting the laboratory for a gynecological checkup (urine, n = 60 and endocervical samples, n = 61). Results: The agreement between the two techniques was 98.90% with a Kappa coefficient of 0...

Background: The classification of HIV-1 strains in subtypes and Circulating Recombinant Forms (CRFs) has helped in tracking the course of the HIV pandemic. In Senegal, which is located at the tip of West Africa, CRF02_AG predominates in the general population and Female Sex Workers (FSWs). In contrast, 40 % of Men having Sex with Men (MSM) in Senegal are infected with subtype C. In this study we analyzed the geographical origins and introduction dates of HIV-1 C in Senegal in order to better understand the evolutionary history of this subtype, which predominates today in the MSM population Methodology/Principal Findings: We used a combination of phylogenetic analyses and a Bayesian coalescent-based approach, to study the phylogenetic relationships in pol of 56 subtype C isolates from Senegal with 3,025 subtype C strains that were sampled worldwide. Our analysis shows a significantly well supported cluster which contains all subtype C strains that circulate among MSM in Senegal. The ...

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Background Genome-wide association studies do not always replicate well across populations, limiting the generalizability of polygenic risk scores (PRS). Despite higher incidence and mortality rates of prostate cancer in men of African descent, much of what is known about cancer genetics comes from populations of European descent. To understand how well genetic predictions perform in different populations, we evaluated test characteristics of PRS from three previous studies using data from the UK Biobank and a novel dataset of 1298 prostate cancer cases and 1333 controls from Ghana, Nigeria, Senegal, and South Africa. Results Allele frequency differences cause predicted risks of prostate cancer to vary across populations. However, natural selection is not the primary driver of these differences. Comparing continental datasets, we find that polygenic predictions of case vs. control status are more effective for European individuals (AUC 0.608–0.707, OR 2.37–5.71) than for African ind...

Background:We recently developed a multi-ancestry polygenic risk score (PRS) that effectively stratifies prostate cancer risk across populations. In this study, we validated the performance of the PRS in the multi-ancestry Million Veteran Program and additional independent studies.Methods:Within each ancestry population, the association of PRS with prostate cancer risk was evaluated separately in each case–control study and then combined in a fixed-effects inverse-variance-weighted meta-analysis. We further assessed the effect modification by age and estimated the age-specific absolute risk of prostate cancer for each ancestry population.Results:The PRS was evaluated in 31,925 cases and 490,507 controls, including men from European (22,049 cases, 414,249 controls), African (8794 cases, 55,657 controls), and Hispanic (1082 cases, 20,601 controls) populations. Comparing men in the top decile (90–100% of the PRS) to the average 40–60% PRS category, the prostate cancer odds ratio (OR) w...