Analytical Performances of Human Immunodeficiency Virus Type 1 RNA-Based Amplix® Real-Time PCR Platform for HIV-1 RNA Quantification

Objectives. We evaluated the performances of Amplix real-time PCR platform developed by Biosynex (Strasbourg, France), combining automated station extraction (Amplix station 16 Dx) and real-time PCR (Amplix NG), for quantifying plasma HIV-1 RNA by lyophilized HIV-1 RNA-based Amplix reagents targeting gag and LTR, using samples from HIV-1-infected adults from Central African Republic. Results. Amplix real-time PCR assay showed low limit of detection (28 copies/mL), across wide dynamic range (1.4–10 log copies/mL), 100% sensitivity and 99% specificity, high reproducibility, and accuracy with mean bias < 5%. The assay showed excellent correlations and concordance of 95.3% with the reference HIV-1 RNA load assay (Roche), with mean absolute bias of +0.097 log copies/mL by Bland-Altman analysis. The assay was able to detect and quantify the most prevalent HIV-1 subtype strains and the majority of non-B subtypes, CRFs of HIV-1 group M, and HIV-1 groups N and O circulating in Central Africa. The Amplix assay showed 100% sensitivity and 99.6% specificity to diagnose virological failure in clinical samples from antiretroviral drug-experienced patients. Conclusions. The HIV-1 RNA-based Amplix real-time PCR platform constitutes sensitive and reliable system for clinical monitoring of HIV-1 RNA load in HIV-1-infected children and adults, particularly adapted to intermediate laboratory facilities in sub-Saharan Africa

Antimicrobial Resistance of Enteric Salmonella in Bangui, Central African Republic

Introduction. The number of Salmonella isolated from clinical samples that are resistant to multiple antibiotics has increased worldwide. The aim of this study was to determine the prevalence of resistant Salmonella enterica isolated in Bangui. Methods. All enteric Salmonella strains isolated from patients in 2008 were identified and serotyped, and the phenotypes of resistance were determined by using the disk diffusion method. Nine resistance-associated genes, blaTEM, blaOXA, blaSHV, tetA, aadA1, catA1, dhfrA1, sul I, and sul II, were sought by genic amplification in seven S.e. Typhimurium strains. Results. The 94 strains isolated consisted of 47 S.e. Typhimurium (50%), 21 S.e. Stanleyville (22%), 18 S.e. Enteritidis (19%), 4 S.e. Dublin (4%), 4 S.e. Hadar (4%), and 1 S.e. Papuana (1%). Twenty-five (28%) were multiresistant, including 20 of the Typhimurium serovar (80%). Two main phenotypes of resistance were found: four antibiotics (56%) and to five antibiotics (40%). One S.e. Typhimurium isolate produced an extended-spectrum β-lactamase (ESBL). Only seven strains of S.e. Typhimurium could be amplified genically. Only phenotypic resistance to tetracycline and aminosides was found. Conclusion. S. Typhimurium is the predominant serovar of enteric S. enterica and is the most widely resistant. The search for resistance genes showed heterogeneity of the circulating strains

Infrequent detection of human papillomavirus infection in head and neck cancers in the Central African Republic: a retrospective study

Abstract We carried out a retrospective study on the prevalence of HPV and genotype distribution by nested PCR and nucleotide sequencing analysis, in formalin-fixed, paraffin-embedded biopsies of 135 head and neck cancers (HNC) and 29 cervical cancers received between 2009 and 2017 for diagnosis at the Laboratoire National de Biologie Clinique et de Santé Publique of Bangui, the capital city of the Central African Republic. One oropharyngeal squamous cell carcinoma sample was positive for HPV type 16. The overall HPV prevalence in HNC biopsies was 0.74% (95% CI: 0.0–2.2). Among the 29 cervical cancer samples, 19 (65.5%; 95% CI: 48.2–82.8) were positive for HPV. These results indicate that HNC are infrequently associated with HPV infection in the Central African Republic

Incidence et risque résiduel de transmission du VIH par transfusion sanguine chez les donneurs réguliers de sang de Bangui et Bimbo en République Centrafricaine en 2019

Contexte et objectif: Dans les pays où hémovigilance n’est pas garantie, les transfusés sont très exposés au risque d’infection par le VIH. L’objectif&nbsp; de cette étude était de déterminer l’incidence et le risque résiduel du VIH chez les donneurs bénévoles de sang (DBS) réguliers. Méthodes: Cette étude a été réalisée au Centre National de Transfusion Sanguine de Bangui. La population d’étude était constituée de DBS&nbsp; réguliers (deux dons et plus) habitant la ville de Bangui, capitale de la République Centrafricaine et Bimbo, entre janvier et décembre 2019. Les tests&nbsp; statistiques ont permis de mettre en évidence les associations. Résultats: Les données de 4030 patients âgés de 18 à 59 ans ont été analysées. L’âge&nbsp; médian était de 25 ans. Le sexe masculin était prépondérant (95 %). Le bon nombre de don varie de 2 à 103. Parmi ces patients suivis 207 ont&nbsp; contracté le VIH, soit une incidence de 0,052 DBS-année. Le taux d’incidence était de 5,20 %. L’incidence du VIH était plus élevée chez les DBS de 50 à&nbsp; 59 ans (0,184 DBS-année ; soit 18,4 %), chez les hommes (0,160 DBS-année ; soit 16 %), les DBS ayant fait 60 à 70 dons (0,25 DBS-année ; soit 25 %)&nbsp; et chez les DBS qui habitent le 6e arrondissement (0,182 ; soit 18,2%). Le risque résiduel de transmission virale par transfusion sanguine était de&nbsp; 30 pour 100 dons. Conclusion: L’incidence du VIH est élevée chez les DBS réguliers âgés (50 à 59 ans), le sexe masculin, les DBS ayant fait plus de&nbsp; dons et ceux qui habitent le 6e arrondissement. Cette étude a montré l’existence d’un risque résiduel de transmission du VIH par transfusion&nbsp; sanguine.&nbsp; &nbsp; English title: Incidence and residual risk of HIV transmission through blood transfusion among regular blood donors in Bangui and Bimbo in the&nbsp; Central African Republic in 2019 Context and objective: Lack of hemovigilance is a great risk factor of HIV transmission in many poor-ressourced countries. The study aimed to&nbsp; determine the incidence and residual risk of HIV in regular voluntary blood donors (VBD). Methods. Data collected in VBD in Bangui, from January to&nbsp; December 2019 where then analyzed using Epi info 7. Statistical tests to highlight the associations. Results. Data from 4030 patients aged 18 to&nbsp; 59 years were analyzed. The median age was 25 years. Males accounted for 95 % of VBD (n = 3830). The donation number varies from 2 to 103. Of&nbsp; the followed patients, 207 contracted HIV, an incidence of 0.052 VBD-year. The incidence rate was 5.20 %. HIV incidence was higher among VBD&nbsp; aged 50 to 59 (0.184 VBD-year; or 18.4 %), among men (0.160 VBSyear; or 16 %), VBD with 60 to 70 donations (0.25 VBD-year; or 25 %) and among&nbsp; VBD living in the 6th arrondissement (0.182; or 18.2 %). The residual risk of viral transmission through blood transfusion was 30 per 100 donations.&nbsp; Conclusion. HIV incidence is high among regular VBD aged 50 to 59 years, male donors, VBD who have made more donations and those who live in&nbsp; the 6th arrondissement. This study showed the existence of a residual risk of HIV transmission through blood transfusion

Performance evaluation of the touchscreen-based Muse™ Auto CD4/CD4% single-platform system for CD4 T cell numeration in absolute number and in percentage using blood samples from children and adult patients living in the Central African Republic

Abstract Background The new microcapillary and fluorescence-based EC IVD-qualified Muse™ Auto CD4/CD4% single-platform assay (EMD Millipore Corporation, Merck Life Sciences, KGaA, Darmstadt, Germany) for CD4 T cell numeration in absolute number and in percentage was evaluated using Central African patients’ samples compared against the reference EC IVD-qualified BD FACSCount (Becton–Dickinson, USA) flow cytometer. Methods EDTA-blood samples from 124 adults, 10 adolescents, 13 children and 3 infants were tested in parallel at 2 reference laboratories in Bangui. Results The Muse™ technique was highly reproducible, with low intra- and inter-run variabilities less than 15%. CD4 T cell counts of Muse™ and BD FACSCount in absolute number and percentage were highly correlated (r2 = 0.99 and 0.98, respectively). The mean absolute bias between Muse™ and BD FACSCount cells in absolute number and percentage were −5.91 cells/µl (95% CI −20.90 to 9.08) with limits of agreement from −77.50 to 202.40 cells/µl, and +1.69 %CD4 (95% CI ±1.29 to +2.09), respectively. The percentages of outliers outside the limits of agreement were nearly similar in absolute number (8%) and percentage (10%). CD4 T cell counting by Muse™ allowed identifying the majority of individuals with CD4 T cell <200, <350 or <750 cells/µl corresponding to the relevant thresholds of therapeutic care, with sensitivities of 95.5–100% and specificities of 83.9–100%. Conclusions The Muse™ Auto CD4/CD4% Assay analyzer is a reliable alternative flow cytometer for CD4 T lymphocyte enumeration to be used in routine immunological monitoring according to World Health Organization recommendations in HIV-infected adults as well as children living in resource-constrained settings

Effectiveness of Xpert MTB/RIF and the Line Probe Assay tests for the rapid detection of drug-resistant tuberculosis in the Central African Republic.

The Xpert MTB/RIF and Line Probe Assay (LPA) tests are more and more frequently used in mycobacteria testing laboratories for the rapid diagnosis of multi-drug resistance (MDR-TB). In this study, we demonstrate the effectiveness of these tests in the Central African Republic. Rifampicin resistance cases detected by the Xpert MTB/RIF during the year 2020 are also underwent first- and second-line LPA, and a first-line of drug susceptibility testing (DST) on solid medium and we compared these results. 101 rifampicin resistance cases based on the Xpert MTB/RIF were detected. Mean age was 34 years [16-81]. The 20-40 years age group represented 73.2% and the male-to-female sex ratio was 1.9:1. Patient profiles were dominated by treatment failure cases (40.6%) followed by relapsed cases (30.7%) and new cases (18.8%). These 101 rifampicin resistance were also detected with the first-line LPA and were confirmed by the DST. Similarly, the isoniazid results obtained with the first-line LPA, were confirmed by the DST, giving a concordance of 100% for these antibiotics. Rifampicin resistance were for the most part due to the absence of the WT8 sequence (56%) and the presence of the Mut3 mutation (53.4%). The majority of the isoniazid resistance (94.2%) were due to the Mut1 mutation in the katG gene and 4.2% of the cases involved both the katG gene and the inhA gene promoter with the Mut1 mutation. The second-line LPA test no resistance to second-line antibiotics. This study demonstrated the effectiveness of the Xpert MTB/RIF and the LPA tests for the rapid diagnosis of MDR-TB in the Central African Republic. However, due to their high cost, these tests have not been extensively deployed in the country. Public authorities and their TB-partners can help make these molecular tests more accessible to fight MDR-TB in the country

Analytical Performances of Human Immunodeficiency Virus Type 1 RNA-Based Amplix® Real-Time PCR Platform for HIV-1 RNA Quantification

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Unusual and unique distribution of anal high-risk human papillomavirus (HR-HPV) among men who have sex with men living in the Central African Republic.

BACKGROUND:High-risk (HR) human papillomavirus (HPV) infection remains a great concern in relation to African men who have sex with men (MSM), especially those infected with HIV. The prevalence of HR-HPV and associated risk factors was estimated in a cross-sectional observational study covering MSM living in Bangui, Central African Republic. METHODS:MSM receiving care at the Centre National de Référence des Infections Sexuellement Transmissibles et de la Thérapie Antirétrovirale, Bangui, were included. HIV serostatus and socio-demographic and behavioral characteristics were collected. HPV DNA was detected and genotyped on anal swabs using Anyplex™ II HPV28 test (Seegene, South Korea), and HSV DNA by in-house real-time PCR. Logistic regression analyses were used to determine risk factors associated with HPV outcomes. RESULTS:42 MSM (mean age, 23.2 years; range, 14-39) including 69.1% HIV-1-positive and 30.9% HIV-negative were prospectively enrolled. The prevalence of anal HPV was 69.1%, including 82.7% of HR-HPV which were multiple in 52.0%. The most prevalent genotypes were HPV-35, HPV-58, HPV-59 and HPV-31. While, HPV-16 and HPV-18 were present in a minority of samples. Multiple HR-HPV infection was more frequent in HIV-positive MSM (41.4%) with 2.7 genotypes per anal samples than in HIV-negative (7.7%) with 1.5 genotypes per anal samples. HPV types included in the prophylactic Gardasil-9® vaccine were detected in 68.9% of specimens and HPV-58 was the most frequently detected. MSM infected by HPV-16 and HPV-18 were all infected by HIV-1. Few anal swabs (11.9%) contained HSV-2 DNA without relationship with HPV detection. Condomless receptive anal intercourse was the main risk factor to being infected with any type of HPV and condomless insertive anal intercourse was significantly less associated with HPV contamination than receptive anal intercourse (Odd ratio = 0.02). CONCLUSION:MSM in Bangui are at-risk of HIV and HR-HPV anal infections. The unusual distribution of HPV-35 as predominant HPV suggests possible geographic specificities in the molecular epidemiology of HR-HPV in sub-Saharan Africa. Scaling up prevention strategies against HPV infection and related cancers adapted for MSM in Africa should be prioritized. Innovative interventions should be conceived for the MSM population living in Bangui