Intrahost evolution leading to distinct lineages in the upper and lower respiratory tracts during SARS-CoV-2 prolonged infection.

Accumulating evidence points to persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in immunocompromised individuals as a source of novel lineages. While intrahost evolution of the virus in chronically infected patients has previously been reported, existing knowledge is primarily based on samples from the nasopharynx. In this study, we investigate the intrahost evolution and genetic diversity that accumulated during a prolonged SARS-CoV-2 infection with the Omicron BF.7 sublineage, which is estimated to have persisted for >1 year in an immunosuppressed patient. Based on the sequencing of eight samples collected at six time points, we identified 87 intrahost single-nucleotide variants, 2 indels, and a 362-bp deletion. Our analysis revealed distinct viral genotypes in the nasopharyngeal (NP), endotracheal aspirate, and bronchoalveolar lavage samples. This suggests that NP samples may not offer a comprehensive representation of the overall intrahost viral diversity. Our findings not only demonstrate that the Omicron BF.7 sublineage can further diverge from its already exceptionally mutated state but also highlight that patients chronically infected with SARS-CoV-2 can develop genetically specific viral populations across distinct anatomic compartments. This provides novel insights into the intricate nature of viral diversity and evolution dynamics in persistent infections.

Mycobacterium heraklionense: An emerging cause of hand tenosynovitis.

Misdiagnosis of Mycobacterium heraklionense tenosynovitis is common due to the challenging identification and perceived rarity of the disease. This can result in delayed therapy initiation and potentially irreversible consequences. In this report, we present an additional case of hand tenosynovitis, which highlights the diagnostic and management challenges of Mycobacterium heraklionense tenosynovitis and provides further evidence of its emergence as a cause of tenosynovitis. Additionally, we provide a comprehensive summary of published case reports that describe Mycobacterium heraklionense tenosynovitis.

Diversity, geographical distribution and predictive factors of Hepatitis C virus genotypes and subtypes in Rwanda.

BACKGROUND: Existing data on the prevalence of hepatitis C virus (HCV) genotypes and subtypes in Rwanda need to be strengthened. The aim of this study was to identify HCV genotypes and subtypes among HCV-infected patients, as well as their geographical distribution in Rwanda, and to identify the social and economic factors that could influence HCV epidemiology which would make it possible to target national preventive and management actions for infected patients. METHODS: This study included 560 patients with confirmed chronic HCV infection. Patients were recruited from various health facilities in the four provinces of Rwanda as well as in the City of Kigali and had never received treatment with direct-acting antiviral (DAAs). HCV viral loads were measured using Cobas® AmpliPrep/Cobas® TaqMan® HCV Quantitative Test, version 2.0. HCV genotyping was performed using an in-house sequencing protocol targeting the NS5B central region. Genotypic HCV prevalence was correlated with patient geographic location, sociodemographic, behavioral, lifestyle, and clinical factors. RESULTS: HCV genotype 4 was detected in 99.3% of the patients, while genotype 3 was identified in 0.7%. A total of eight (8) HCV subtypes were detected, with 4k being the predominant subtype nationwide (49.5%), followed by subtypes 4r (21.2%), 4q (16.2%), 4v (7.9%), 4b (2.0%), 4l (1.8%), 4c and 3h represent 0.7% each. Our findings reveal subtype distribution variations among provinces. Subtype 4k was prevalent across regions, particularly in Kigali (64.0%) and the Eastern Province (61.6%). Subtype 4q was more common in the northern province (40.7%), 4r in the southern (43.9%) and western provinces (37.1%), and 4v in the eastern province (17.8%). Farmers exhibit a distinct infection profile compared to other occupations, showing a lower prevalence of subtype 4k but a higher prevalence of subtype 4r. CONCLUSIONS: Our study revealed that HCV infection is unevenly distributed in Rwanda, dominated by HCV genotype 4, with considerable heterogeneity in the repartition of the different subtypes. We found potential associations between rural/urban lifestyles and HCV subtype profiles. Determined HCV distribution and diversity can serve as basis not only for HCV infection awareness and prevention campaigns, but also success and guidance for personalized treatment.

New Diagnostic Strategy for Onychomycosis: First-Line Utilization of DermaGenius® PCR and Calcofluor Microscopy Combined with Selective Culturing.

Onychomycosis (OM) is a widespread infection requiring prolonged treatment with potential side effects. Diagnostic certainty is therefore essential before initiating antifungal therapy. Molecular biology has already shown benefits in reducing the time to diagnosis, providing technical ease, and increasing sensitivity for the respective species that molecular tests can detect. Nevertheless, causative agents are numerous, and culture remains essential, particularly for detecting non-dermatophytes mold infections. This study compared the performance of three different diagnostic strategies: conventional culture technique, the multiplex DermaGenius® 2.0 PCR (DG), and a mixed PCR/culture algorithm guided by the result of direct examination with calcofluor (DEC). The mixed algorithm (MA) prioritizes DG PCR and DEC as the primary diagnostic tools, supplemented by selective sample inoculation when mycelial elements are visualized in DEC and when DG PCR fails to detect any fungus or identifies a fungus with morphology differing from that observed in DEC (filamentous fungi versus yeasts). With only 13% of samples requiring inoculation, MA emerged as the most effective strategy, demonstrating significantly higher sensitivity (98.18%; p < 0.001) compared to single-method approaches (78.18% for DG PCR alone and 74.55% for culture alone) while maintaining a specificity comparable to DG PCR (100%). This new approach saves time in result delivery, requires fewer human resources, and increases diagnostic accuracy to better meet the needs of clinicians.

Saccharomyces cerevisiae fungemias: how heterogenous is their management?

Saccharomyces cerevisiae is a yeast used mainly as a probiotic for prevention or treatment of diarrhoea. However, the prevalence of S. cerevisiae fungemia has risen over the past years, notably among patients with predisposing factors. This retrospective study presents 21 cases of S. cerevisiae fungemia at the University Hospital of Liege from 2000 to 2022, their clinical relevance and therapeutic management. Each patient presented one or several risk factors prior to fungemia. The isolated strains presented high minimal inhibitory concentration for fluconazole, while MICs for amphotericin B, voriconazole and echinocandins were low. Some patients received antifungal therapy, while for others only central and peripheral lines were removed and probiotics discontinued. The MICs obtained for voriconazole and echinocandins makes them an alternative treatment to fluconazole and amphotericin B as reported in other studies. Since a S. cerevisiae fungemia can induce the same complications as candidemia, follow-up blood cultures should be collected and metastatic foci should be looked for. This study showed an important discrepancy in the clinical management of infections due to S. cerevisiae and highlights the need for guidelines.

Dengue and chikungunya: future threats for Northern Europe?

Arthropod-borne viral diseases are likely to be affected by the consequences of climate change with an increase in their distribution and intensity. Among these infectious diseases, chikungunya and dengue viruses are two (re)emergent arboviruses transmitted by Aedes species mosquitoes and which have recently demonstrated their capacity for rapid expansion. They most often cause mild diseases, but they can both be associated with complications and severe forms. In Europe, following the establishment of invasive Aedes spp, the first outbreaks of autochtonous dengue and chikungunya have already occurred. Northern Europe is currently relatively spared, but climatic projections show that the conditions are permissive for the establishment of Aedes albopictus (also known as the tiger mosquito) in the coming decades. It is therefore essential to question and improve the means of surveillance in northern Europe, at the dawn of inevitable future epidemics.

First comprehensive untargeted metabolomics study of suramin-treated Trypanosoma brucei: an integrated data analysis workflow from multifactor data modelling to functional analysis.

INTRODUCTION: Human African trypanosomiasis, commonly known as sleeping sickness, is a vector-borne parasitic disease prevalent in sub-Saharan Africa and transmitted by the tsetse fly. Suramin, a medication with a long history of clinical use, has demonstrated varied modes of action against Trypanosoma brucei. This study employs a comprehensive workflow to investigate the metabolic effects of suramin on T. brucei, utilizing a multimodal metabolomics approach. OBJECTIVES: The primary aim of this study is to comprehensively analyze the metabolic impact of suramin on T. brucei using a combined liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) approach. Statistical analyses, encompassing multivariate analysis and pathway enrichment analysis, are applied to elucidate significant variations and metabolic changes resulting from suramin treatment. METHODS: A detailed methodology involving the integration of high-resolution data from LC-MS and NMR techniques is presented. The study conducts a thorough analysis of metabolite profiles in both suramin-treated and control T. brucei brucei samples. Statistical techniques, including ANOVA-simultaneous component analysis (ASCA), principal component analysis (PCA), ANOVA 2 analysis, and bootstrap tests, are employed to discern the effects of suramin treatment on the metabolomics outcomes. RESULTS: Our investigation reveals substantial differences in metabolic profiles between the control and suramin-treated groups. ASCA and PCA analysis confirm distinct separation between these groups in both MS-negative and NMR analyses. Furthermore, ANOVA 2 analysis and bootstrap tests confirmed the significance of treatment, time, and interaction effects on the metabolomics outcomes. Functional analysis of the data from LC-MS highlighted the impact of treatment on amino-acid, and amino-sugar and nucleotide-sugar metabolism, while time effects were observed on carbon intermediary metabolism (notably glycolysis and di- and tricarboxylic acids of the succinate production pathway and tricarboxylic acid (TCA) cycle). CONCLUSION: Through the integration of LC-MS and NMR techniques coupled with advanced statistical analyses, this study identifies distinctive metabolic signatures and pathways associated with suramin treatment in T. brucei. These findings contribute to a deeper understanding of the pharmacological impact of suramin and have the potential to inform the development of more efficacious therapeutic strategies against African trypanosomiasis.

Effect of screening for Neisseria gonorrhoeae and Chlamydia trachomatis on incidence of these infections in men who have sex with men and transgender women taking HIV pre-exposure prophylaxis (the Gonoscreen study): results from a randomised, multicentre, controlled trial.

BACKGROUND: Guidelines recommend screening for Neisseria gonorrhoeae and Chlamydia trachomatis at three anatomical sites (urethra, anus, and pharynx) every 3 months (3 × 3) in men who have sex with men (MSM) and transgender women taking HIV pre-exposure prophylaxis (PrEP). We present the first randomised controlled trial to compare the effect of screening versus non-screening for N gonorrhoeae and C trachomatis on the incidence of these infections in MSM and transgender women taking PrEP. METHODS: A multicentre, randomised, controlled trial of 3 × 3 screening for N gonorrhoeae and C trachomatis versus non-screening was done among MSM and transgender women taking PrEP in five HIV reference centers in Belgium. Participants attended the PrEP clinics quarterly for 12 months. N gonorrhoeae and C trachomatis was tested at each visit in both arms, but results were not provided to the non-screening arm, if asymptomatic. The primary outcome was incidence rate of N gonorrhoeae and C trachomatis infections in each arm, assessed in the per-protocol population. Non-inferiority of the non-screening arm was proven if the upper limit of the 95% CI of the incidence rate ratio (IRR) was lower than 1·25. This trial is registered with ClinicalTrials.gov, NCT04269434, and is completed. FINDINGS: Between Sept 21, 2020, and June 4, 2021, 506 participants were randomly assigned to the 3 × 3 screening arm and 508 to the non-screening arm. The overall incidence rate of N gonorrhoeae and C trachomatis was 0·155 cases per 100 person-days (95% CI 0·128-0·186) in the 3 × 3 screening arm and 0·205 (95% CI 0·171-0·246) in the non-screening arm. The incidence rate was significantly higher in the non-screening arm (IRR 1·318, 95% CI 1·068-1·627). Participants in the non-screening arm had a higher incidence of C trachomatis infections and symptomatic C trachomatis infections. There were no significant differences in N gonorrhoeae infections. Participants in the non-screening arm consumed significantly fewer antimicrobial drugs. No serious adverse events were reported. INTERPRETATION: We failed to show that non-screening for N gonorrhoeae and C trachomatis is non-inferior to 3 × 3 screening in MSM and transgender women taking PrEP in Belgium. However, screening was associated with higher antibiotic consumption and had no effect on the incidence of N gonorrhoeae. Further research is needed to assess the benefits and harms of N gonorrhoeae and C trachomatis screening in this population. FUNDING: Belgian Health Care Knowledge Centre.

Oral minocycline as systemic therapy for uncomplicated venous access device-related bloodstream infection with coagulase-negative staphylococci after allogeneic hematopoietic cell transplantation.

BACKGROUND: Venous access device-related bloodstream infection (VAD-BSI) with coagulase-negative staphylococci (CoNS) is a common complication after allogeneic hematopoietic cell transplantation (alloHCT). Standard systemic antimicrobial therapy for uncomplicated VAD-BSI with methicillin-resistant CoNS consists of intravenous (IV) vancomycin (vanco). This requires hospitalization, needs new competent venous access, exposes patients to potential toxicity (mainly renal) and increases the risk of commensal flora dysbiosis with selection of vanco-resistant enterococci. Combined with VAD management (removal or antibiotic locks), oral minocycline (mino) has been evaluated as an alternative systemic therapy for the treatment of uncomplicated VAD-BSIs with CoNS at our center, primarily when the reference treatment with IV vanco was not possible (renal failure or allergy) or when hospitalization was refused by patients. Here, we retrospectively report our single center experience with this mino-based approach. PATIENTS AND METHODS: From January 2012 to December 2020, 24 uncomplicated VAD-BSIs with CoNS in 23 alloHCT patients were treated with oral mino as systemic antibiotic therapy in combination with VAD management. VAD were implantable ports (n = 17), tunneled catheter (n = 1) or PIC-lines (n = 6). Staphylococci were S. epidermidis (n = 21) or S. haemolyticus (n = 3). Mino was administered with a loading dose of 200 mg followed by 100 mg BID for 7-14 days. For 8 VAD-BSIs, patients were initially treated with IV vanco for the first 1-3 days followed by oral mino, while 16 VAD-BSIs were treated with oral mino as the sole antimicrobial agent for systemic therapy. VAD management consisted of catheter removal (for tunneled catheters and PIC-lines, n = 7) or antibiotic locks with vanco (n = 15) or gentamicin (n = 2) administered at least 3 times a week for 14 days (for ports). RESULTS: Overall, clearance of bacteremia (as assessed by negativity for the same CoNS of surveillance peripheral blood cultures drawn between day+ 3 and +30 after initiation of systemic therapy) was achieved in all but 1 patient (with port) who had persistent bacteremia at day +9. No complication such as suppurative thrombophlebitis, endocarditis, distant foci of infection or BSI-related death was observed in any patient during the 3-month period after initiation of treatment. Regarding the 17 port-BSI cases for which VAD conservative strategy was attempted, failure of 3-month VAD preservation was documented in 7/17 cases and 3-month recurrence of VAD-BSI was observed in 3/17 cases (with 1 patient with cellulitis). Treatment with mino was well tolerated except for a mild skin rash in one patient. CONCLUSION: Further prospective studies are needed to evaluate efficacy and safety of this approach.

Development and optimization of a one step process for the production and sterilization of liposomes using supercritical CO2.

Liposomes are very interesting drug delivery systems for pharmaceutical and therapeutic purposes. However, liposome sterilization as well as their industrial manufacturing remain challenging. Supercritical carbon dioxide is an innovative technology that can potentially overcome these limitations. The aim of this study was to optimize a one-step process for producing and sterilizing liposomes using supercritical CO2. For this purpose, a design of experiment was conducted. The analysis of the experimental design showed that the temperature is the most influential parameter to achieve the sterility assurance level (SAL) required for liposomes (≤10-6). Optimal conditions (80 °C, 240 bar, 30 min) were identified to obtain the fixed critical quality attributes of liposomes. The conditions for preparing and sterilizing empty liposomes of various compositions, as well as liposomes containing the poorly water-soluble drug budesonide, were validated. The results indicate that the liposomes have appropriate physicochemical characteristics for drug delivery, with a size of 200 nm or less and a PdI of 0.35 or less. Additionally, all liposome formulations demonstrated the required SAL and sterility at concentrations of 5 and 45 mM, with high encapsulation efficiency.

Genetic diversity of Echinococcus multilocularis specimens isolated from Belgian patients with alveolar echinococcosis using EmsB microsatellites analysis.

The genetic diversity of Echinococcus multilocularis (E. multilocularis) specimens isolated from patients with alveolar echinococcosis (AE), is a major field of investigation to correlate with sources of infection, clinical manifestations and prognosis of the disease. Molecular markers able to distinguish samples are commonly used worldwide, including the EmsB microsatellite. Here, we report the use of the EmsB microsatellite polymorphism data mining for the retrospective typing of Belgian specimens of E. multilocularis infecting humans. A total of 18 samples from 16 AE patients treated between 2006 and 2021 were analyzed through the EmsB polymorphism. Classification of specimens was performed through a dendrogram construction in order to compare the similarity among Belgian samples, some human referenced specimens on the EWET database (EmsB Website for the Echinococcus Typing) and previously published EmsB profiles from red foxes circulating in/near Belgium. According to a comparison with human European specimens previously genotyped in profiles, the 18 Belgian ones were classified into three EmsB profiles. Four specimens could not be assigned to an already known profile but some are near to EWET referenced samples. This study also highlights that some specimens share the same EmsB profile with profiles characterized in red foxes from north Belgium, the Netherlands, Luxembourg and French department near to the Belgian border. Furthermore, Belgian specimens present a genetic diversity and include one profile that don't share similarities with the ones referenced in the EWET database. However, at this geographical scale, there is no clear correlation between EmsB profiles and geographical location. Further studies including additional clinical samples and isolates from foxes and rodents of south Belgium are necessary to better understand the spatial and temporal circumstances of human infections but also a potential correlation between EmsB profiles and parasite virulence.

The landscape of drug resistance in Plasmodium falciparum malaria in the Democratic Republic of Congo: a mapping systematic review.

CONTEXT: The Democratic Republic of Congo (DRC), one of the most malaria-affected countries worldwide, is a potential hub for global drug-resistant malaria. This study aimed at summarizing and mapping surveys of malaria parasites carrying molecular markers of drug-resistance across the country. METHODS: A systematic mapping review was carried out before July 2023 by searching for relevant articles through seven databases (PubMed, Embase, Scopus, African Journal Online, African Index Medicus, Bioline and Web of Science). RESULTS: We identified 1541 primary studies of which 29 fulfilled inclusion criteria and provided information related to 6385 Plasmodium falciparum clinical isolates (collected from 2000 to 2020). We noted the PfCRT K76T mutation encoding for chloroquine-resistance in median 32.1% [interquartile interval, IQR: 45.2] of analyzed malaria parasites. The proportion of parasites carrying this mutation decreased overtime, but wide geographic variations persisted. A single isolate had encoded the PfK13 R561H substitution that is invoked in artemisinin-resistance emergence in the Great Lakes region of Africa. Parasites carrying various mutations linked to resistance to the sulfadoxine-pyrimethamine combination were widespread and reflected a moderate resistance profile (PfDHPS A437G: 99.5% [IQR: 3.9]; PfDHPS K540E: 38.9% [IQR: 47.7]) with median 13.1% [IQR: 10.3] of them being quintuple IRN-GE mutants (i.e., parasites carrying the PfDHFR N51I-C59R-S108N and PfDHPS A437G-K540E mutations). These quintuple mutants tended to prevail in eastern regions of the country. Among circulating parasites, we did not record any parasites harboring mutations related to mefloquine-resistance, but we could suspect those with decreased susceptibility to quinine, amodiaquine, and lumefantrine based on corresponding molecular surrogates. CONCLUSIONS: Drug resistance poses a serious threat to existing malaria therapies and chemoprevention options in the DRC. This review provides a baseline for monitoring public health efforts as well as evidence for decision-making in support of national malaria policies and for implementing regionally tailored control measures across the country.

Occurrence of Vibrio spp. in Selected Recreational Water Bodies in Belgium during 2021 Bathing Season.

In recent years, a global increase in the number of reports of human vibriosis involving V. cholerae non-O1/O139 (NOVC) and other Vibrio spp. has been observed. In this context, the Belgian National Reference Center for Vibrio conducted an assessment of the presence of Vibrio spp. in recreational waters. Water sampling was performed monthly in different lakes in Wallonia and Flanders, including the North Sea. The collected water was then filtrated and cultured, and Vibrio spp. was quantified according to the Most Probable Number (MPN). Presumptive colonies were confirmed via MALDI-TOF, and PCR for virulence genes was applied if justified. No Vibrio spp. was found in the analyzed water bodies in Wallonia. However, NOVC was isolated from three different lakes in Flanders and from coastal water. In addition, V. alginolyticus and V. parahaemolyticus were also detected in coastal water. No clear impact of the pH and temperature was observed on Vibrio spp. occurrence. Our study demonstrates the presence of Vibrio spp. in different bathing water bodies, mostly in the north of Belgium, and supports the recommendation to include Vibrio spp. as a water quality indicator for bathing water quality assessment to ensure the safety of water recreational users in Belgium.

Gut Microbiota Associated with Clostridioides difficile Carriage in Three Clinical Groups (Inflammatory Bowel Disease, C. difficile Infection and Healthcare Workers) in Hospital Field.

Clostridioides difficile is an anaerobic spore-forming Gram-positive bacterium. C. difficile carriage and 16S rDNA profiling were studied in three clinical groups at three different sampling times: inflammatory bowel disease (IBD) patients, C. difficile infection (CDI) patients and healthcare workers (HCWs). Diversity analysis was realized in the three clinical groups, the positive and negative C. difficile carriage groups and the three analysis periods. Concerning the three clinical groups, ß-diversity tests showed significant differences between them, especially between the HCW group and IBD group and between IBD patients and CDI patients. The Simpson index (evenness) showed a significant difference between two clinical groups (HCWs and IBD). Several genera were significantly different in the IBD patient group (Sutterella, Agathobacter) and in the CDI patient group (Enterococcus, Clostridioides). Concerning the positive and negative C. difficile carriage groups, ß-diversity tests showed significant differences. Shannon, Simpson and InvSimpson indexes showed significant differences between the two groups. Several genera had significantly different relative prevalences in the negative group (Agathobacter, Sutterella, Anaerostipes, Oscillospira) and the positive group (Enterococcus, Enterobacteriaceae_ge and Enterobacterales_ge). A microbiota footprint was detected in C. difficile-positive carriers. More experiments are needed to test this microbiota footprint to see its impact on C. difficile infection.

Correlation of antifungal susceptibility and sequence types within Cryptococcus neoformans VNI from HIV patients, and ERG11 gene polymorphism.

INTRODUCTION: Here we tested the correlation between minimum inhibitory concentrations (MICs) of major antifungal agents and sequence types (STs) within Cryptococcus neoformans VNI isolates, and explored the ERG11 gene of included strains. MATERIALS AND METHODS: We analysed 23 C. neoformans strains categorised into two groups according to the distribution of the ST profile in Kinshasa clinics (Democratic Republic of Congo): major ST [ST93 (n = 15)], and less common STs [ST659 (n = 2), ST5 (n = 2), ST4 (n = 1), ST 53 (n = 1), ST31 (n = 1), and ST69 (n = 1)]. The MICs of the major antifungal agents [amphotericin B (AMB), 5-fluorocytosine (5FC) and fluconazole (FCZ)] were determined following EUCAST guidelines. ERG11 gene sequences were extracted from whole genome sequence of the isolates and compared with the wild-type gene sequence of the C. neoformans VNI. RESULTS: Although major ST isolates appeared to have lower median MICs for AMB and 5FU than less common ST isolates (0.50 vs. 0.75 mg/L for AMB, 2 vs. 4 mg/L for 5FU, respectively), FCZ susceptibility was similar in both groups (4 mg/L) (p-value >0.05). The susceptibility profile of C. neoformans strains separately considered did not significantly affect the patients' clinical outcomes (p-value >0.05). Furthermore, two structural modalities of the ERG11 gene were observed: (1) that of the reference gene, and (2) that containing two exonic silent point substitutions, and one intronic point substitution located in a sequence potentially involved in pre-mRNA splicing (c.337-22C > T); with no association with the MICs of the isolates (p-value >0.05). CONCLUSIONS: The lack of association/correlation found in this study calls for further investigations to better understand the mechanisms of C. neoformans resistance to antifungal agents.

Cluster Analysis Identifies Distinct Patterns of T-Cell and Humoral Immune Responses Evolution Following a Third Dose of SARS-CoV-2 Vaccine in People Living with HIV.

(1) Background: Many vaccines require higher, additional doses or adjuvants to provide adequate protection for people living with HIV (PLWH). Despite their potential risk of severe coronavirus disease 2019, immunological data remain sparse, and a clear consensus for the best booster strategy is lacking. (2) Methods: Using the data obtained from our previous study assessing prospective T-cell and humoral immune responses before and after administration of a third dose of SARS-CoV-2 vaccine, we assessed the correlations between immune parameters reflecting humoral and cellular immune responses. We further aimed at identifying distinct clusters of patients with similar patterns of immune response evolution to determine how these relate to demographic and clinical factors. (3) Results: Among 80 PLWH and 51 healthcare workers (HCWs) enrolled in the study, cluster analysis identified four distinct patterns of evolution characterised by specific immune patterns and clinical factors. We observed that immune responses appeared to be less robust in cluster A, whose individuals were mostly PLWH who had never been infected with SARS-CoV-2. Cluster C, whose individuals showed a particularly drastic increase in markers of humoral immune response following the third dose of vaccine, was mainly composed of female participants who experienced SARS-CoV-2. Regarding the correlation study, although we observed a strong positive correlation between markers mirroring humoral immune response, markers of T-cell response following vaccination correlated only in a lesser extent with markers of humoral immunity. This suggests that neutralising antibody titers alone are not always a reliable reflection of the magnitude of the whole immune response. (4) Conclusions: Our findings show heterogeneity in immune responses among SARS-CoV-2 vaccinated PLWH. Specific subgroups could therefore benefit from distinct immunization strategies. Prior or breakthrough natural infection enhances the activity of vaccines and must be taken into account for informing global vaccine strategies among PLWH, even those with a viro-immunologically controlled infection.

Actinomyces israelii and Fusobacterium nucleatum brain abscess in an immunocompetent patient: case report.

Introduction: Brain abscess is the most common focal infectious neurological injury. Until the nineteenth century this condition was fatal, however the development of neuroimaging for early diagnosis, neurosurgery and antibiotic therapy in the twentieth century has led to new therapeutic strategies decreasing mortality from 50 % in the 1970s to less than 10 % nowadays. In this context we report a case of brain abscess with a dental origin. Case report: A immunocompetent man without any addiction presented to the emergency department with dysarthria and frontal headache at home. The clinical examination was normal. Further investigations revealed a polymicrobial brain abscess as a consequence of an ear, nose or throat (ENT) infection with locoregional extension with a dental starting point involving Actinomyces israelii and Fusobacterium nucleatum . In spite of a rapid diagnosis and a neurosurgical management associated with an optimal treatment by a dual therapy made of ceftriaxone and metronidazole the patient unfortunately died. Conclusion: This case report shows that despite a low incidence and a good prognosis following the diagnosis, brain abscesses can lead to patient's death. Thereby, when the patient's condition and urgency allow, a thorough dental examination of patients with neurological signs following the recommendations would improve the diagnosis made by the clinician. The use of microbiological documentation, the respect of pre-analytical conditions, the interaction between the laboratory and the clinicians are indispensable for an optimal management of these pathologies.

Human adaptation and diversification in the Microsporum canis complex.

The Microsporum canis complex consists of one zoophilic species, M. canis, and two anthropophilic species, M. audouinii and M. ferrugineum. These species are the most widespread zoonotic pathogens causing dermatophytosis in cats and humans worldwide. To clarify the evolutionary relationship between the three species and explore the potential host shift process, this study used phylogenetic analysis, population structure analysis, multispecies coalescent analyses, determination of MAT idiomorph distribution, sexual crosses, and macromorphology and physicochemical features to address the above questions. The complex of Microsporum canis, M. audouinii and M. ferrugineum comprises 12 genotypes. MAT1-1 was present only in M. canis, while the anthropophilic entities contained MAT1-2. The pseudocleistothecia were yielded by the mating behaviour of M. canis and M. audouinii. Growth rates and lipase, keratinolysis and urea hydrolytic capacities of zoophilic M. canis isolates were all higher than those of anthropophilic strains; DNase activity of M. ferrugineum exceeded that of M. canis. The optimum growth temperature was 28 °C, but 22 °C favoured the development of macroconidia. Molecular data, physicochemical properties and phenotypes suggest the adaptation of zoophilic M. canis to anthropophilic M. ferrugineum, with M. audouinii in an intermediate position.

Reconstruction of SARS-CoV-2 outbreaks in a primary school using epidemiological and genomic data.

Mathematical modelling studies have shown that repetitive screening can be used to mitigate SARS-CoV-2 transmission in primary schools while keeping schools open. However, not much is known about how transmission progresses within schools and whether there is a risk of importation to households. During the academic year 2020-2021, a prospective surveillance study using repetitive screening was conducted in a primary school and associated households in Liège (Belgium). SARS-CoV-2 screening was performed via throat washing either once or twice a week. We used genomic and epidemiological data to reconstruct the observed school outbreaks using two different models. The outbreaker2 model combines information on the generation time and contact patterns with a model of sequence evolution. For comparison we also used SCOTTI, a phylogenetic model based on the structured coalescent. In addition, we performed a simulation study to investigate how the accuracy of estimated positivity rates in a school depends on the proportion of a school that is sampled in a repetitive screening strategy. We found no difference in SARS-CoV-2 positivity between children and adults and children were not more often asymptomatic compared to adults. Both models for outbreak reconstruction revealed that transmission occurred mainly within the school environment. Uncertainty in outbreak reconstruction was lowest when including genomic as well as epidemiological data. We found that observed weekly positivity rates are a good approximation to the true weekly positivity rate, especially in children, even when only 25% of the school population is sampled. These results indicate that, in addition to reducing infections as shown in modelling studies, repetitive screening in school settings can lead to a better understanding of the extent of transmission in schools during a pandemic and importation risk at the community level.

[Evaluation of the knowledge on alveolar echinococcosis among general practitioners in the province of Liege : impact of a formative intervention]. / Évaluation des connaissances de l'échinococcose alvéolaire réalisée auprès des médecins généralistes de la Province de Liège : impact d'une intervention formative.

Alveolar echinococcosis is an indigenouszoonosis caused by the growth of the larval stage of a small tapeworm, Echinococcus multilocularis. Despite a low incidence in Belgium, with about 10 cases on average recorded per year, this parasitosis poses a real public health problem because it often remains difficult to diagnose and is potentially fatal in the absence of treatment. General practitioners are on the frontline, but they do not always know enough about the disease, which causes a delay in the diagnosis and impacts the prognosis. The present study aims to assess the level of knowledge of alveolar echinococcosis among general practitioners in the province of Liège via a questionnaire, on the one hand, and to increase their level of knowledge via a formative intervention using a video capsule, on the other hand. We have performed a randomized controlled experimental study, which showed that general practitioners in the province of Liège have limited knowledge on alveolar echinococcosis. This mainly concerns symptomatology, diagnostic tools and treatment. The formative intervention carried out allowed increasing their level of knowledge about this disease.

L'échinococcose alvéolaire est une zoonose autochtone provoquée par le développement tissulaire de la larve d'un petit ténia, Echinoccocus multilocularis. Malgré une faible incidence en Belgique, avec une moyenne de 10 cas recensés par an, cette parasitose pose un réel problème de santé publique car elle reste souvent difficile à diagnostiquer et potentiellement mortelle en l'absence de traitement. Les médecins généralistes sont en première ligne, mais ils ne connaissent pas toujours suffisamment la maladie, ce qui retarde le diagnostic et compromet le pronostic. La présente étude visait à évaluer les connaissances à propos de l'échinococcose alvéolaire des médecins généralistes de la province de Liège via un questionnaire approprié et à accroître leur niveau de connaissance via une intervention formative sous forme de capsule vidéo. Nous avons réalisé une étude à visée expérimentale randomisée contrôlée qui a montré que les médecins généralistes de la province de Liège ont des connaissances partielles sur la symptomatologie, les outils de diagnostic et le traitement. L'intervention formative réalisée a permis d'augmenter leur niveau de connaissances à propos de cette maladie.