Temporal Dynamics of Interferon Gamma Responses in Children Evaluated for Tuberculosis

BACKGROUND: Development of T-cells based-Interferon gamma (IFNgamma) assays has offered new possibilities for the diagnosis of latent tuberculosis infection (LTBI) and active disease in adults. Few studies have been performed in children, none in France. With reference to the published data on childhood TB epidemiology in the Paris and Ile de France Region, we considered it important to evaluate the performance of IGRA (QuantiFERON TB Gold In Tube(R), QF-TB-IT) in the diagnosis and the follow-up through treatment of LTBI and active TB in a cohort of French children. METHODOLOGY/PRINCIPAL FINDINGS: 131 children were recruited during a prospective and multicentre study (October 2005 and May 2007; Ethical Committee St Louis Hospital, Paris, study number 2005/32). Children were sampled at day 0, 10, 30, 60 (except Healthy Contacts, HC) and 90 for LTBI and HC, and a further day 120, and day 180 for active TB children. Median age was 7.4 years, with 91% of the children BCG vaccinated. LTBI and active TB children undergoing therapy produced significant higher IFNgamma values after 10 days of treatment (p = 0.035). In addition, IFNgamma values were significantly lower at the end of treatment compared to IFNgamma values at day 0, although the number of positive patients was not significantly different between day 0 and end of treatment. CONCLUSIONS/ SIGNIFICANCE: By following quantitative IFNgamma values in each enrolled child with LTBI or active TB and receiving treatment, we were able to detect an increase in the IFNgamma response at day 10 of treatment which might allow the confirmation of a diagnosis. In addition, a decline in IFNgamma values during treatment makes it possible for clinicians to monitor the effect of preventive or curative therapy

Bacille CDC GROUP IVc-2 : caractérisation, phylogénie, épidémiologie, sensibilité aux antibiotiques

CDC Group IVc-2 est un bacille à Gram négatif, aérobie strict, mobile grâce à une ciliature péritriche, oxydase et catalase positives et non fermentant. Connu depuis les années 80, il a d'abord été rapproché de Bordetella bronchiseptica puis parfaitement différencié biochimiquement de cette espèce en 1986 par Pickett (87). Sa position taxonomique longtemps indéterminée a été précisée en 1999 (74, 83, 116) et nous y avons contribué (74). Bactérie de l'environnement hydrique (7, 63, 82)...PARIS5-BU-Necker : Fermée (751152101) / SudocSudocFranceF

Estimation of two wear factors for total hip arthroplasty : A simulation study based on musculoskeletal modelling

Background: Primary causes of surgical revision after total hip arthroplasty are polyethylene wear and implant loosening. These factors are particularly related to joint friction and thus patients' physical activity. Assessing implant wear over time according to patients' morphology and physical activity level is key to improve follow-up and patients' quality of life. Methods: An approach initially proposed for tibiofemoral prosthetic wear estimation was adapted to compute two wear factors (force-velocity, directional wear intensity) using a musculoskeletal model. It was applied on 17 participants with total hip arthroplasty to compute joint angular velocity, contact force, sliding velocity, and wear factors during common daily living activities. Findings: Differences were observed between gait, sitting down, and standing up tasks. An incremental increase of both global wear factors (time-integral) was observed during gait from slow to fast speeds (p ≤ 0.01). Interestingly, these two wear factors did not result in same trend for sitting down and standing up tasks. Compared to gait, one cycle of sitting down or standing up tends to induce higher friction-related wear but lower cross-shear-related wear. Depending on the wear factor, significant differences can be found between sitting down and gait at slow speed (p ≤ 0.05), and between sitting down (p ≤ 0.05) or standing up (p ≤ 0.05) and gait at fast speed. Furthermore, depending on the activity, wear can be fostered by joint contact force and/or sliding velocity. Interpretation: This study demonstrated the potential of wear estimation to highlight activities inducing a higher risk of implant wear after total hip arthroplasty from motion capture data.</p

Longitudinal survey of <it>Staphylococcus aureus </it>in cystic fibrosis patients using a multiple-locus variable-number of tandem-repeats analysis method

<p>Abstract</p> <p>Background</p> <p><it>Staphylococcus aureus </it>infection in patients with cystic fibrosis (CF) is frequent and may be due to colonization by a few pathogenic lineages. Systematic genotyping of all isolates, methicillin-susceptible <it>S. aureus </it>(MSSA) as well as methicillin-resistant <it>S. aureus </it>(MRSA) is necessary to identify such lineages and follow their evolution in patients. Multiple-locus variable-number tandem repeat analysis (MLVA/VNTR) was used to survey <it>S. aureus </it>clinical isolates in a French paediatric CF centre.</p> <p>Results</p> <p>During a 30 months period, 108 patients, aged 2 to 21 years, regularly followed up at the centre, provided sputum for culture. From 79 patients, a total of 278 isolates were genotyped by MLVA, resolving into 110 genotypes and 19 clonal complexes (CC) composed of similar or closely related isolates. 71% of the strains were distributed into four main CCs, in term of number of isolates and number of genotypes. <it>Spa </it>(<it>Staphylococcus </it>protein A) typing was performed on representative samples, showing an excellent concordance with MLVA. In 17 patients, strains from two to four different CCs were recovered over time. On six occasions, <it>S. aureus </it>isolates with the same genotype were shared by 2 different patients and they belonged to one of the four main clusters. Methicillin-resistance was observed in 60% of the isolates, 90% of which belonged to the main clonal complexes CC8, CC45 and CC5. In 5 patients, methicillin-resistance of <it>S. aureus </it>isolates was not associated with the <it>mecA </it>gene: for four patients, it was due to overproduction of β-lactamase, leading to BOR-SA (borderline <it>S. aureus</it>) isolates, while a strain showing probably a new modified penicillin-binding capacity (MOD-SA) was observed from one patient.</p> <p>Conclusion</p> <p>Systematic genotyping of <it>S. aureus </it>isolates recovered from sputum of CF children allows a thorough analysis of the strains responsible for sporadic as well as chronic colonization and the follow up of their evolution over time. We show here that more than 70% of these strains belong to 4 major CCs. MSSA as well as MRSA, BOR-SA and MOD-SA isolates can persist over several years, despite antibiotic treatments.</p

Detection of β-D-glucan for the diagnosis of invasive fungal infection in children with hematological malignancy

International audienceObjectives: The ß-D-glucan assay (BDG) has been added to the EORTC/MSG criteria for the diagnosis of invasive fungal infections (IFI), but data from pediatric populations is scarce. The aim of this study was to evaluate performance of BDG in a cohort of hemato-oncological children with hematological malignancy at risk for IFI.Methods: 113 patients were included through an 18-month period. In addition to routine IFI screening, BDG was assayed once a week. IFIs were classified using EORTC/MSG criteria without including the BDG results. Performances were assessed after a ROC analysis for optimization and multivariate analysis to detect the causes of false positivity.Results: 8 proven and 4 probable IFIs, and 7 possible IFIs were diagnosed in 9 and 7 patients, respectively. Sensitivity and specificity increased from 75% and 56% to 100% and 91.1%, respectively when considering the whole population and patients not having received any antifungals prior to the test. Multivariate analysis revealed that being younger than 7, severe colitis/mucositis, recent administration of polyvalent immunoglobulins and digestive colonization with Enterococcus sp were independent risk factors for false positivity.Conclusions: BDG is a valuable test to detect IFI in pediatric patients not previously treated with antifungals and to detect the occurrence of chronic infection