Search

International audience; Background HIV pre-exposure prophylaxis (PrEP) data in men who have sex with men (MSM) in west Africa are essential to guide its large-scale implementation. We assessed the uptake of event-driven and daily PrEP, HIV incidence, and changes over time in sexual behaviours and prevalence of bacterial sexually transmitted infections (STIs) in MSM in Burkina Faso, Côte d'Ivoire, Mali, and Togo. Methods We did a prospective cohort study from Nov 20, 2017, to April 14, 2020, in four community-based clinics in Abidjan (Côte d'Ivoire), Bamako (Mali), Lomé (Togo), and Ouagadougou (Burkina Faso). Participants were MSM aged 18 years or older at substantial risk of HIV infection. Participants could choose between event-driven (2+1+1 dosing) and daily oral PrEP (tenofovir disoproxil fumarate 300 mg plus emtricitabine 200 mg), switch regimen, and discontinue or restart PrEP. We compared HIV incidence in this study with that of the same cohort before the availability of PrEP (CohMSM). Statistical analysis included the Kaplan-Meier method and mixed-effects regression models. This study is registered with ClinicalTrials.gov, NCT03459157. Findings We followed up 598 participants for a total of 743•6 person-years. At enrolment, 445 (74%) of 598 participants chose event-driven PrEP and 153 (26%) of 598 chose daily PrEP. 60 (13%) of 445 and 65 (42%) of 153 partici pants switched PrEP regimen at least once (p

Many common and rare variants associated with hematologic traits have been discovered through imputation on large-scale reference panels. However, the majority of genome-wide association studies (GWASs) have been conducted in Europeans, and determining causal variants has proved challenging. We performed a GWAS of total leukocyte, neutrophil, lymphocyte, monocyte, eosinophil, and basophil counts generated from 109,563,748 variants in the autosomes and the X chromosome in the Trans-Omics for Precision Medicine (TOPMed) program, which included data from 61,802 individuals of diverse ancestry. We discovered and replicated 7 leukocyte trait associations, including (1) the association between a chromosome X, pseudo-autosomal region (PAR), noncoding variant located between cytokine receptor genes (CSF2RA and CLRF2) and lower eosinophil count; and (2) associations between single variants found predominantly among African Americans at the S1PR3 (9q22.1) and HBB (11p15.4) loci and monocyte and lymphocyte counts, respectively. We further provide evidence indicating that the newly discovered eosinophil-lowering chromosome X PAR variant might be associated with reduced susceptibility to common allergic diseases such as atopic dermatitis and asthma. Additionally, we found a burden of very rare FLT3 (13q12.2) variants associated with monocyte counts. Together, these results emphasize the utility of whole-genome sequencing in diverse samples in identifying associations missed by European-ancestry-driven GWASs.

Resume Introduction Le glaucome est la principale cause de cecite irreversible dans le monde. Le but de notre travail a ete d’evaluer les resultats tonometriques du traitement au laser SLT chez les patients glaucomateux. Materiels et methodes Il s’agit d’une etude prospective des patients glaucomateux ayant consulte du 1er octobre 2017 au 31 juillet 2018. Une trabeculoplastie selective au laser SLT sur 180° du trabeculum inferieur a ete realisee. La pression intraoculaire a ete mesuree avant puis a 1, 15, 30, 60, 90 et 120 jours apres traitement. Resultats Nous avons collige 35 yeux de 31 patients. L’âge moyen etait de 59,3 ans. (ET = 8,4 ans), avec des extremes de 43 et 77 ans. La pression intraoculaire initiale moyenne etait a 20,1 mmHg (ET = 7 mmHg). Un jour apres le laser, cette moyenne etait de 17,6 mmHg (ET = 8,4) soit une baisse de 12,4 %. A 30 jours, elle etait de 15,3 mmHg (ET = 5,4 mmHg) soit une reduction de 23,9 %. Apres 60, et 90, on notait une baisse respective de 13,9 %, et 15,4 %. A j120, 43,3 % des yeux traites avaient une baisse d’au moins 20 %. La complication majeure a ete l’hypertonie oculaire dans 14,2 % des cas. Conclusion La trabeculoplastie selective au laser permet de reduire la pression intraoculaire et le nombre de collyres hypotonisants chez les patients glaucomateux. Elle apparait comme une alternative pertinente dans nos pays. Ces resultats sont a confirmer par une plus grande serie et un suivi plus long.

Background Benin, a country eligible for Gavi support, changed the presentation of the 13-valent pneumococcal vaccine (PCV13) from the single-dose vial (SDV) to the multi-dose vial (MDV). The present work aims to evaluate the process of making this decision as well as programmatic and logistic impacts. Methods WHO protocol for post-introduction evaluation (PIE) was used. Programmatic impact was evaluated by comparing PCV13 coverage and dropout rates with a comparator vaccine administered simultaneously over similar 6-month periods prior to and after the transition. This impact was also appreciated from observation of multi-dose vial management practices during immunization sessions. Logistic impact was measured from the analysis of storage capacities, waste management and vaccine losses. Results Decision to move to PCV13 MDV was taken at EPI level. Activities planned to support this switch were partially implemented. Impact on vaccination coverage and PCV13 dropout rates in relation with the transition to PCV13 MDV was not detected. The study found that 63% of the health staff surveyed knew and applied WHO's multidose vial policy (MDVP). Vaccines opened vials were found in 83% of health facilities visited. PCV13 MDV (37%) was one of the 3 main vaccines found with open vials in health facility refrigerators. Vaccination risky practices were observed during immunization sessions in 83% of health facilities. The main risky practice was the lack of indication of the date and hour of opening vials (56%). There was a reduction of the volume occupied by vaccines at central store by 47%. Net storage volume per fully immunized child (FIC) decreased from 69.5 to 41 m3. PCV13 MDV allows for 40% reduction in the amount of waste produced by vaccination. PCV13 open vial loss rate has increased from 3 to 7%. Conclusion Benin’s experience in transition to an MDV presentation of PCV13 reveals the need for better preparation and planning.

With deep learning applications becoming more practical, practitioners are inevitably faced with datasets corrupted by a variety of noise such as measurement errors, mislabeling and estimated surrogate inputs/outputs, which can have negative impacts on the optimization results. As a safety net, it is natural to improve the robustness to noise of the optimization algorithm which updates the network parameters in the final process of learning. Previous works revealed that the first momentum used in Adam-like stochastic gradient descent optimizers can be modified based on the Student's t-distribution to produce updates robust to noise. In this paper, we propose AdaTerm which derives not only the first momentum but also all of the involved statistics based on the Student's t-distribution, providing for the first time a unified treatment of the optimization process under the t-distribution statistical model. When the computed gradients statistically appear to be aberrant, AdaTerm excludes them from the update and reinforce its robustness for subsequent updates; otherwise, it normally updates the network parameters and relaxes its robustness for the following updates. With this noise-adaptive behavior, AdaTerm's excellent learning performance was confirmed via typical optimization problems with several cases where the noise ratio is different and/or unknown. In addition, we proved a new general trick for deriving a theoretical regret bound without AMSGrad., 27 pages

Aflatoxins are produced by fungi of the genus Aspergillus that colonize many foodstuffs during agricultural production, harvesting, transportation, storage, and food processing. In view of these aflatoxins toxicity to humans, their presence in foods such as cereals and oilseeds constitutes a major challenge for global food security, health and nutrition. This study was therefore initiated to assess the level of aflatoxin contamination of various foodstuffs sold in urban and semi-urban markets in Burkina Faso, and to evaluate the carcinogenic risk which the consuming population is exposed to. Two hundred and twelve foodstuff samples were collected in two large cities (Ouagadougou and Bobo Dioulasso) and three semi urban localities (Cinkansé, Dakola and Niangoloko). Aflatoxins contents in foodstuffs were determined by immunoaffinity chromatography and human health risk assessment was performed by using the Monte Carlo algorithm. The aflatoxins contents determination showed that 41.50% of studied samples were contaminated with concentrations up to 182.28 μg/kg for AFB1 in peanuts. Chronic Daily Intake, calculated based on the consumption patterns assumed in this study, was estimated to be higher in large cities (CDI = 33.68 μg/kg bw in Ouagadougou and 10.18 μg/kg bw in Bobo Dioulasso) than in semi urban localities (CDI = 4.29 μg/kg bw in Cinkansé, CDI = 0.39 μg/kg bw in Dakola and CDI = 0.18 μg/kg bw in Niangoloko). The MOE determination showed that the sorghum meal and whole grain maize consumption was associated to the carcinogenic risk for public health in large cities (the percentile 95 of MOE = 3316 for rice, 4511 for peanuts, 3334 for sorghum meal and 4530 for whole grain maize). In semi urban localities, no carcinogenic risk was observed to public health. These results should inspire the country's sanitary and agricultural authorities to undertake actions to fight against the agricultural food products contamination by aflatoxins in order to safeguard the population's health.

Resume Introduction : Le diabete sucre constitue un veritable probleme de sante publique dans le monde entier et prend de l’ampleur dans les pays en voie de developpement. Objectif : Determiner les sujets a risque de diabete de type 2 (DT2) et facteurs de risque associes en milieu estudiantin. Materiel et Methode : Il s’est agi d’une etude transversale descriptive chez des volontaires etudiants recrutes de facon systematique, le 23 novembre 2013, dans la ville de Ouagadougou (Burkina Faso). Le score finlandais de risque de diabete (Finnish Diabetes Risk Score) a ete utilise. Chaque volontaire a ete interviewe a l’aide d’une fiche individuelle, suivi d’un examen clinique et de la mesure de la glycemie capillaire. Resultats : Au total, 564 volontaires ont ete inclus dans l’etude. L’âge moyen etait de 25,2 ± 3,8 ans, et le sexe-ratio (hommes/femmes) de 3,9. Au niveau de l’heredite, une histoire familiale de diabete et d’hypertension arterielle (HTA) etait notee chez respectivement 2,1 % (n = 12) et 18,3 % (n = 103) des sujets enquetes. Un evenement cardiovasculaire familial a ete note chez 2 % (n = 11) des sujets. Une HTA etait connuechez 2,7 % (n = 15) d’entre eux. L’indice de masse corporelle (IMC) moyen etait de 21,8 ± 2,9 kg/m2. Un surpoids et une obesite androide etaient notes chez 35 et 8 sujets, respectivement. Une obesite abdominale etait notee chez 30 sujets. L’HTA etaitnotee chez 15 sujets. Seuls 17 sujets ont rapporte la pratique d’une activite physique reguliere. La glycemie capillaire moyenne etait de 4,5 mmol/L; 11 sujets avaient une hyperglycemie capillaire. Le risque de survenue de diabete a ete serie en risque faible (533 personnes; 96,70 %), risque legerement eleve (17 personnes; 3,08 %), risque modere et eleve chez une personne chacun (0,18 %). Conclusion : En milieu estudiantin a Ouagadougou, la frequence des sujets ayant unrisque moderement eleve a eleve de developper un DT2 etait faible. La prevention dudiabete et des facteurs de risque associes est la solution idoine afin de lutter contre le DT2. Le score clinique de risque de DT2 (Finnish Diabetes Risk Score) offre unealternative d’evaluation de risque de survenue du DT2 dans une population particuliere, ce qui permettra la mise en oeuvre de moyens de prevention.

Purpose Laryngeal papillomatosis is the most common benign tumor of the larynx of children. It is characterized by the development of exophytic proliferative lesions in the mucosa of the airways. Human papillomavirus (HPV) has been recognized as a causal agent among which HPV types 6 and 11 are the most frequently implicated. This disease affects the vocal cords and other important functions of the child. The difficulty of treatment is related to the high recurrence of papilloma growth after surgical removal. The objective of this study was to describe the implication of HPV6 and HPV11 in cases of laryngeal papillomatosis histologically confirmed in Ouagadougou. Materials and methods This was a descriptive cross-sectional study based on histologically diagnosed archival tissue; obtained in the last ten years (2007 to 2017) in the anatomy and cyto-pathology laboratories in Burkina Faso. These fixed and paraffin-embedded tissues were deparaffinized with xylene before HPV DNA extraction; then HPV6 and HPV 11 were identified by real-time multiplex PCR. Results The prevalence of low-risk HPV infection (HPV-LR) was 54.84% in histologically confirmed laryngeal papillomatosis in Ouagadougou. Among the HPV-LR positive samples, HPV6 and HPV11 genotype prevalence's were respectively 41.17% and 35.3% while the HPV6 / HPV11 co-infection was 23.53%. Conclusions The results show the implication of HPV6 and HPV11 in laryngeal papillomatosis in Burkina Faso with a high prevalence.

After intensive control efforts, human African trypanosomiasis (HAT) was declared eliminated in Côte d'Ivoire as a public health problem in December 2020 and the current objective is to achieve the interruption of the transmission (zero cases). Reaching this objective could be hindered by the existence of an animal reservoir of Trypanosoma (T.) brucei (b.) gambiense. In the framework of a study led in 2013 to assess the role of domestic animals in the epidemiology of HAT in the two last active foci from Côte d'Ivoire (Bonon and Sinfra), plasmas were sampled from four species of domestic animals for parasitological (microscopic examination by the buffy coat technique (BCT)), serological (immune trypanolysis (TL)) and molecular (specific PCR: TBR for T. brucei s.l., TCF for T. congolense forest type, TVW for T. vivax and PCR for T. b. gambiense) testing. In order to improve the understanding of the involvement/role of these animals in the transmission of T. b. gambiense, we have quantified in this study the IgG response to whole saliva extracts of Glossina palpalis gambiensis in order to perform an association analysis between anti-saliva responses and the positivity of diagnostic tests. Cattle and pigs had significantly higher rates of anti-tsetse saliva responses compared to goats and sheep (p 0.01). In addition, the anti-tsetse saliva responses were strongly associated with the parasitology (BCT+), serology (TL+) and PCR (TBR+ and TCF+) results (p 0.001). These associations indicate a high level of contacts between the positive/infected animals and tsetse flies. Our findings suggest that protecting cattle and pigs against tsetse bites could have a significant impact in reducing transmission of both animal and human trypanosome species, and advocates for a "One health" approach to better control African trypanosomosis in Côte d'Ivoire.

The Belahourou granite pluton (BG pluton) is a magmatic body that belongs to the Djibo greenstone belt, north Burkina Faso. Calc-alkaline in composition and 2132 ± 4 Ma in age (U-Pb zircon), this pluton is bordered by the curved Belahourou-Souma (BS) sinistral shear-zone, NNW-trending in the northern half of the pluton and WNW-trending in the southern part. In order to study the emplacement mechanism relationships with the BS shear-zone and the gold-deposits, the pluton and its host-rocks have been subjected to standard and modern mapping techniques (airborne geophysics, satellite imagery, anisotropy of magnetic susceptibility - AMS - and microstructural observations), in addition to field observations. The pluton, 100 km 2 in area, 16 km in length and 7 km in width, is surrounded by metamorphic formations, turbiditic clastic to the west and volcanic material along the southern and eastern sides. To the north the pluton is in contact with granodioritic and gabbroic rocks. Pluton emplacement was likely instigated by opening of a tension gash associated with NW-directed, sinistral shearing along the curved BSS. The overall NW-trending magnetic lineations inside the pluton support this interpretation. The microstructures indicate that shearing continued during pluton cooling, explaining the inside-pluton magmatic to orthogneissic transition, and after cooling, explaining the mylonitic microstructures against the BS shear-zone. A 3D conceptual representation integrates the available data and concludes that the pluton is late-tectonic with respect to the regional D2 deformation event. Once emplaced, the pluton may have provided low pressure zones, at lithological contacts and/or inside brittle fractures in the host formations, concentrating the mineralizing fluids that were pressurized during pluton cooling, and that helped to precipitate the ore.

The Inata cluster of gold deposits is one of ten gold deposits currently in exploitation in Burkina Faso. The aim of this work was to assess the influence and contribution of the magmatic events in the metallogenic system. Our approach is based on detailed field observation and petrography of different lithologies encountered in the main pit (NP). The intrusions were targeted and reasonably, six types were described: (i) gabbro, (ii) porphyrytic diorite, (iii) foliated intrusion, (iv) quartz-feldspar (micro) diorite, (v) dacite, (vi) fine grained diorite. No clear relationship was established between gabbro and the mineralization but quartz ± feldspar dioritic and dacitic compositions may have contributed in fluid remobilizing, some of which developed pressure shadow with optimal energy. Inata has been described as mesothermal gold deposit. The series of intrusions as we have interpreted may help in the understanding of the several episodes of gold mineralization at Inata. In summary, this paper is a contribution that highlights the closeness of the magmatic bodies in relationship with the gold deposit in that part of the Birimian terrane. We think this could help in enhancing interest for some other similar environment in Burkina Faso, particularly when supported with whole rock analysis.

Objectives: In this study, we monitored the seroprevalence of HBV-HDV co-infection in different population groups in the Western part of Burkina Faso, and described the genetic diversity of the detected virus strains. Methods: Between October 2013 and December 2014, venous blood samples were collected from different cohorts (blood donors, pregnant women, outpatients) in the western region of Burkina Faso. Samples were tested for HBsAg and total anti-HDV antibodies. Positive samples were further analysed for HBV-DNA and HDV-RNA. Genotyping of the detected virus strains was done by nucleotide sequencing and phylogenetic analyses. Results: A total of 841 participants were included in this study. The mean age was 27.45 years (range: 7–89 years). HBsAg was found in 117 (13.9%) participants. Of the HBsAg positive samples, 4 (3.4%) were positive for total anti-HDV antibodies and negative for HDV RNA. Phylogenetic analyses based on the HBV complete genome (n = 10) and S fragment sequences (n = 35) showed that all strains belonged to genotype E. Conclusions: Our study showed a high HBsAg prevalence, but a low rate of HDV co-infection in HBsAg carriers from western Burkina Faso. The predominance of HBV genotype E in the country was confirmed. Our findings contribute to a better understanding of the burden of HBV and HDV infection in western Burkina Faso. Keywords: HBV, HDV, Seroprevalence, HBV genotype, Burkina Faso

Resume Introduction Le pot de toilette en plastique peut etre une source d’eczema de contact des fesses. Nous en rapportons une serie de 20 cas colliges a Ouagadougou. Patients et methode Il s’agissait une etude transversale sur une periode de 5 ans au centre Raoul-Follereau et a l’hopital Saint-Camille de Ouagadougou a partir des dossiers de patients. Resultats Nous avons collige 20 cas. L’âge moyen des patients etait de 4 ans. Le debut de la symptomatologie coincidait avec l’introduction du pot de toilette plastique pour l’apprentissage de la proprete. L’examen dermatologique notait des lesions erythemato-squameuses, crouteuses, hyperpigmentees, aux limites irregulieres siegeant sur la moitie externe des fesses, en demi-lune a convexite externe chez 16 patients. Elles etaient exulcerees melliceriques sur toute la surface des fesses chez les 4 autres patients. Le diagnostic d’eczema de contact au plastique du pot de toilette etait retenu : un eczema chronique chez 12 patients, lichenifie chez 4 patients et surinfecte chez 4 autres patients. La prise en charge consistait en l’eviction du pot de toilette, l’application de dermocorticoide, precedee d’une antibiotherapie en cas de surinfection. Une regression complete des lesions etait obtenue en 2 semaines a 2 mois. Conclusion La reproduction de la zone de contact des fesses avec le pot de toilette, par les lesions d’eczema, est un element devant faire evoquer un eczema de contact des fesses chez des enfants qui utilisent un pot de toilette en plastique.

Erythropoiesis is a complex physiological process by which erythroid progenitors proliferate and differentiate into nonnucleated red blood cells. Several methods can be used to monitor in vitro the differentiation of erythroid precursors, and hence the toxic effects of drugs, chemicals, or pollutants. One of the most commonly available assay of erythropoiesis is the microscopic observation of differentiated cells after benzidine staining, which forms a blue complex with hemoglobin. However, this method is laborious and does not provide accurate results since it heavily relies on the reader's interpretation. Moreover, benzidine is a carcinogen and a highly reactive molecule which forces the reader to microscopically count differentiated and non-differentiated cells within a short time frame (5 min). Here we have developed a simple, inexpensive, in-vitro spectrophotometric assay to measure erythroid differentiation using K562 cell line as a model. Materials needed included 96-well round-bottomed microplates and a microplate reader. Remarkably, carcinogenic benzidine was replaced by its isomeric tetramethyl derivative, the 3,3′, 5,5′- tetramethylbenzidine (TMB), which presents several advantages: it is cheap, not mutagenic and a ready-to-use chromogenic substrate. A small volume (50 μl) of TMB added to the samples forms a blue complex in 15 min, and the reaction can be easily stopped and stabilized by the addition of H2SO4. The yellow precipitate is then solubilized, and the absorbance is measured at 450 nm. In addition, the suitability of the assay to determine the effects of compounds on erythroid differentiation was further tested with known inhibitors (artemisinin derivatives) of K562 differentiation. Overall, the reported methodology permits to measure in an accurate and reproducible manner the K562 differentiation and can be used for medium throughput screenings (MTS) of compounds or environmental toxics with potential erythro-toxicity and ability to inhibit erythroid differentiation.