Université des Sciences de la Santé

Central nervous system (CNS) infections are an important cause of morbidity and mortality among people living with HIV (PLWHIV), particularly in resource-limited settings. Cryptococcosis, toxoplasmosis and cerebral malaria often present with overlapping neurological symptoms, complicating diagnosis where confirmatory tests are unavailable. This study aimed to determine the prevalence and associated signs and symptoms of parasitic and fungal infections with neurological tropism in PLWHIV hospitalized in Libreville. A retrospective review was conducted at the Infectious Diseases Ward of the Centre Hospitalier Universitaire de Libreville (IDW-CHUL) between April and September 2021. Data were recorded from the medical files of PLWHIV hospitalised for suspected cryptococcal meningoencephalitis presenting with fever and headache alone or associated with other neurological signs. Diagnoses of cryptococcosis, toxoplasmosis, and malaria were based on microscopy, cryptococcal antigen testing, and brain CT scan. Cases of tuberculosis, other bacterial or viral meningitis were not included. Sociodemographic, clinical, and immunological data were analysed, and associations between symptoms and CNS infections were assessed. Among 255 hospitalised PLHIV, most were aged under 55 years (86.3%, n = 220), female (72.5%, n = 185), and severely immunosuppressed (CD4 < 200 cells/mm³, 57.2%, n = 127). Parasitic or fungal infections were identified in 32.9% (n = 84) of cases: cryptococcosis (14.5%), cerebral toxoplasmosis (13.7%), and complicated malaria (9.8%), with 5.1% presenting co-infections. Advanced HIV disease (WHO stage III-IV) was significantly associated with cryptococcosis and toxoplasmosis (p < 0.01). Fever and headache (81.2%, n = 207) were the most common symptoms. According to diagnosis, fever, headache, seizures, and/or focal deficits were more suggestive of toxoplasmosis (cOR 3.5, 95%CI [1.0-12.4], p = 0.05), while prostration was more frequent in malaria (cOR 2.9, 95%CI [0.98-9.0], p = 0.05), and neck stiffness was characteristic of cryptococcosis. Parasitic and fungal CNS infections remain frequent and severe in hospitalised PLWHIV in Libreville, mainly in advanced disease with profound immunosuppression. In the absence of diagnostic tools, recognition of symptom clusters may guide syndromic triage and empirical therapy.

Abstract Background Anaemia affects one-third of women of reproductive age worldwide and is one of the most common complications of pregnancy. The aetiologies are multiple and sometimes intertwined in the same woman. Anaemia is the expression of an iron deficiency in the majority of cases, but there are manyother causes, such as malaria and other parasitic infections, infection with HIV, nutritional deficiencies and haemoglobinopathies. This study aimed to provide knowledge on the prevalence and determinants of anaemia in a population of pregnant women from Lambaréné in Gabon. Methods In a cross-sectional study, pregnant women attending antenatal clinics were invited to participate by providing sociodemographic data as well as blood, urine and stool samples for the diagnosis of anaemia, malaria, schistosomiasis, and soil-transmitted helminths. Data were analysed through univariate and multivariate logistic regression. Results A total of 371 women were enrolled, with a median age of 24 years (min–max: 14–45 years). The prevalence of anaemia was 74.4% (276/371), with higher proportions among adolescent girls (81.3%), those from rural settings(78%), primigravida (80.2%), nulliparous (79%), and HIV-infected (89.7%), and women positive for malaria (93%), schistosomiasis (82.4%), and soil-transmitted helminths (85.7%). Multivariate analysis revealed strong evidence that malaria was associated with anaemia in the study population, with an adjusted odds ratio (aOR) of 7.36 (95% confidence interval: 1.51--35.85), p=0.01, and weak evidence that soil-transmitted helminths could also be associated with anaemia, with an OR of 3.95 (95% CI: 0.95--16.46, p=0.05). Interpretation Anaemia in pregnant women is very common in the study area and is a severe public health problem in this region of Gabon. Malaria and other prevalent infections are important risk factors associated with anaemia in pregnant women. National public health policies should be implemented or strengthened to address the issue of anaemia in pregnant women.

Introductionles troubles du sommeil sont variés et de plus en plus fréquents chez les sujets africains, mais leur réelle prévalence est peu connue sur le continent. L´objectif de cette étude était de déterminer la prévalence des troubles du sommeil et les facteurs associés à la qualité du sommeil en milieu rural à Nikki au Bénin en 2022.Méthodesil s'est agi d'une étude transversale à visée analytique réalisée chez les sujets âgés d'au moins 18 ans dans la commune de Nikki en 2022. La sélection des patients a été effectuée par sondage aléatoire à deux degrés. Les troubles du sommeil ont été diagnostiqués sur la base d'échelles validées telles le Pittsburg Sleep Quality Questionnaire, le Questionnaire de Berlin, le Score d'Epworth, le Restless Legs Syndrome Questionnaire, l'Index de Sévérité de l'Insomnie et le Munich Parasomnia Screening Questionnaire.Résultatsau terme de l'étude, 879 participants ont été inclus. Une prédominance féminine a été observée avec un sex ratio (F/H) de 1,9. La qualité du sommeil était mauvaise chez 52,21%. La prévalence de l'insomnie était de 9,44%, celle du syndrome des jambes sans repos de 21,39% et 21,16% pour la somnolence diurne. Un syndrome d'apnée du sommeil était présent chez 2,50% des participants. Le sexe masculin et le tabagisme actif étaient associés à la mauvaise qualité du sommeil avec respectivement p=0,03 et p=0,021.Conclusionles troubles du sommeil sont fréquents en milieu rural à Nikki, nécessitant des campagnes de dépistage de masse pour en réduire la charge.

The Human T-cell Leukemia Virus Type 1 (HTLV-1) infection is endemic in Gabon, and despite the high prevalence, very few cases of HTLV-1 associated diseases are sporadically described. A cross-sectional study was conducted in the main teaching hospital of Gabon. Using serological and molecular techniques, plasma samples were tested and nucleic materials of all positive samples extracted from the buffy coat, then a polymerase chain reaction (PCR) was performed to detect fragments of 220 and 522-base-pairs of HTLV-1 Tax/Rex and Env genes, respectively. From March to September 2022, a total of 352 participants (51 median age, IQR 36-62) were recruited, consisting of 290 (82.4%) patients and 65 (17.6%) patients' family members. Of them, 36 (10.2%) samples were ELISA seropositive, and according to WB criteria, 22 were HTLV-1 positive (6.3%), 7 indeterminate (2%), 5 seronegative (1.4%) and 2 had HTLV seroreactivity (0.6%). The HTLV-1 infection was confirmed in 26 individuals (22 patients and 4 among their family members) with an overall prevalence estimated at 7.39% (26/352), and 3.7% (10/272) prevalence for diseases associated to HTLV-1, obtained from all clinical diagnoses. The link assessment between HTLV-1 infection and diseases' occurrence revealed 10.5% of cases of Adult T-cell Leukemia/Lymphoma (2/19), 55.6% of tropical spastic paraparesis/HTLV-1-associated myelopathy (5/9) and 60% of inflammatory myopathies (3/5). Most of the detected genotypes of HTLV-1 strains belonged to the central African HTLV-1b, four defined as HTLV-1a including a-Na, a-Wa and a-TC subclades, and one belonging to the HTLV-1d. Then, assessment of HTLV-1 intrafamilial transmission and risk factors reported one case of mother-to-child HTLV-1 transmission, and significant impacts of association between HTLV-1 infection with the gender and birthplaces were observed. Here, we discussed both the prevalence of HTLV-1 infection among patients and diseases previously described as associated to this retrovirus in Gabon. Our findings highlight the necessity to develop strategies to prevent and properly manage this infection.

Quelles politiques pour structurer l’offre de soins palliatifs à domicile au Québec ? Une analyse alimentée de résultats d’une recherche-action participative. Un article de la revue Cahiers francophones de soins palliatifs (Numéro spécial : 25 ans de partage des savoirs) diffusée par la plateforme Érudit.

Context/Purpose: The urban ecosystem of Akanda behind the airport of the capital city of Libreville in Gabon, harbors diverse and dense mosquito larval habitats and hotspots for malaria and arboviruses transmission. To effectively conduct vector control, it is imperative to adopt an integrated approach by adding biolarvicides to the toolbox. The main objective of this study is to evaluate the efficacy of a biolarvicide under laboratory and field conditions. Methods: In Gabon, this current pilot and preliminary study sought to test the efficacy of the biolarvicide VectorBac® Water dispersable Granule (WG) (VBG) during the rainy season period (March to May 2024) under field and laboratory conditions following the 2005 World Health Organisation protocol. Results: For the bioassay of VBG, in the laboratory, the required dose to kill 88% and 100% of the larvae in rearing cups was 0.001 g/mL and 0.01 g/mL respectively. Under field conditions, the percentage larval density reduction irrespective of the microhabitat type ranged from 90 to 100% and the mosquito larval density reduction between test and control groups in the field differed statistically (X2=34; p = 0.026). Conclusion: The larvae from Akanda tested under field and laboratory conditions were very sensitive to the standard dose recommended by the manufacturer after 24 hrs post-treatment with VBG. This pilot study provides baseline information that is required to conduct a longitudinal study to evaluate the residual effect of VBG in different ecological settings in Gabon.

SummaryBackgroundThe population structure of the malaria parasite Plasmodium falciparum can reveal underlying adaptive evolutionary processes. Selective pressures to maintain complex genetic backgrounds can encourage inbreeding, producing distinct parasite clusters identifiable by population structure analyses.MethodsWe analysed population structure in 3783 P falciparum genomes from 21 countries across Africa, provided by the MalariaGEN Pf7 dataset. We used Principal Coordinate Analysis to cluster parasites, identity by descent (IBD) methods to identify genomic regions shared by cluster members, and linkage analyses to establish their co-inheritance patterns. Structural variants were reconstructed by de novo assembly and verified by long-read sequencing.FindingsWe identified a strongly differentiated cluster of parasites, named AF1, comprising 47 (1·2%) of 3783 samples analysed, distributed over 13 countries across Africa, at locations over 7000 km apart. Members of this cluster share a complex genetic background, consisting of up to 23 loci harbouring many highly differentiated variants, rarely observed outside the cluster. IBD analyses revealed common ancestry at these loci, irrespective of sampling location. Outside the shared loci, however, AF1 members appear to outbreed with sympatric parasites. The AF1 differentiated variants comprise structural variations, including a gene conversion involving the dblmsp and dblmsp2 genes, and numerous single nucleotide polymorphisms. Several of the genes harbouring these mutations are functionally related, often involved in interactions with red blood cells including invasion, egress, and erythrocyte antigen export.InterpretationWe propose that AF1 parasites have adapted to some unidentified evolutionary niche, probably involving interactions with host erythrocytes. This adaptation involves a complex compendium of interacting variants that are rarely observed in Africa, which remains mostly intact despite recombination events. The term cryptotype was used to describe a common background interspersed with genomic regions of local origin.FundingBill & Melinda Gates Foundation.