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Dive into the research topics where Guillaume Gras is active.

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Featured researches published by Guillaume Gras.


PLOS ONE | 2011

High Burden of Non-Influenza Viruses in Influenza-Like Illness in the Early Weeks of H1N1v Epidemic in France

Nathalie Schnepf; Matthieu Resche-Rigon; Antoine Chaillon; Anne Scemla; Guillaume Gras; Oren Semoun; Pierre Taboulet; Jean-Michel Molina; François Simon; Alain Goudeau; Jérôme LeGoff

Background Influenza-like illness (ILI) may be caused by a variety of pathogens. Clinical observations are of little help to recognise myxovirus infection and implement appropriate prevention measures. The limited use of molecular tools underestimates the role of other common pathogens. Objectives During the early weeks of the 2009–2010 flu pandemic, a clinical and virological survey was conducted in adult and paediatric patients with ILI referred to two French University hospitals in Paris and Tours. Aims were to investigate the different pathogens involved in ILI and describe the associated symptoms. Methods H1N1v pandemic influenza diagnosis was performed with real time RT-PCR assay. Other viral aetiologies were investigated by the molecular multiplex assay RespiFinder19®. Clinical data were collected prospectively by physicians using a standard questionnaire. Results From week 35 to 44, endonasal swabs were collected in 413 patients. Overall, 68 samples (16.5%) were positive for H1N1v. In 13 of them, other respiratory pathogens were also detected. Among H1N1v negative samples, 213 (61.9%) were positive for various respiratory agents, 190 in single infections and 23 in mixed infections. The most prevalent viruses in H1N1v negative single infections were rhinovirus (62.6%), followed by parainfluenza viruses (24.2%) and adenovirus (5.3%). 70.6% of H1N1v cases were identified in patients under 40 years and none after 65 years. There was no difference between clinical symptoms observed in patients infected with H1N1v or with other pathogens. Conclusion Our results highlight the high frequency of non-influenza viruses involved in ILI during the pre-epidemic period of a flu alert and the lack of specific clinical signs associated with influenza infections. Rapid diagnostic screening of a large panel of respiratory pathogens may be critical to define and survey the epidemic situation and to provide critical information for patient management.


Scandinavian Journal of Infectious Diseases | 2011

Efficacy of a combined oral clindamycin?rifampicin regimen for therapy of staphylococcal osteoarticular infections.

Jaroslaw Czekaj; Aurélien Dinh; Andréea Anamaria Moldovan; Pierre Vaudaux; Guillaume Gras; Pierre Hoffmeyer; Daniel Pablo Lew; Louis Bernard; Ilker Uckay

Abstract A majority of osteoarticular and implant-related infections are due to staphylococci and biofilm formation. Combined therapy including rifampicin is frequently recommended. Indeed, rifampicin penetrates biofilms and kills adherent staphylococci, but cannot be administered as monotherapy because of the rapid emergence of resistant mutants. While several antibiotic combinations including rifampicin have been implemented, evaluation of the clindamycin–rifampicin combination has been neglected, presumably because of the emergence of alternative combinations, such as quinolone–rifampicin, and the fear of potential antagonistic interactions. We report a limited series of 20 patients (3 immune-suppressed) with 6 arthroplasty infections, 4 other implant infections, 7 native arthritis, and 3 osteomyelitis, who were all successfully treated with this oral combination for >75% of the antibiotic course (median duration 45 days). The excellent outcomes obtained with this antimicrobial combination after a mean follow-up of 2.6 y (range 1.0–6.1 y) warrant further clinical and microbiological studies for implementing this regimen in routine practice.


Journal of Acquired Immune Deficiency Syndromes | 2012

Patterns of adherence to raltegravir-based regimens and the risk of virological failure among HIV-infected patients: the RALTECAPS cohort study.

Guillaume Gras; Marie-Paule Schneider; Matthias Cavassini; Frédéric Lucht; Magalie Loilier; Renaud Verdon; Louis Bernard; Jean-Jacques Parienti

Abstract:Adherence patterns and their influence on virologic outcome are well characterized for protease inhibitor (PI)- and non-nucleoside reverse transcriptase inhibitor (NNRTI)–based regimens. We aimed to determine how patterns of adherence to raltegravir influence the risk of virological failure. We conducted a prospective multicenter cohort following 81 HIV-infected antiretroviral-naive or experienced subjects receiving or starting twice-a-day raltegravir-based antiretroviral therapy. Their adherence patterns were monitored using the Medication Events Monitoring System. During follow-up (188 days, ±77), 12 (15%) of 81 subjects experienced virological failure. Longer treatment interruption [adjusted odds ratio per 24-hour increase: 2.4; 95% confidence interval: 1.2 to 6.9; P < 0.02] and average adherence (odds ratio per 5% increase: 0.68; 95% confidence interval: 0.46 to 1.00, P < 0.05) were both independently associated with virological failure controlling for prior duration of viral suppression. Timely interdose intervals and high levels of adherence to raltegravir are both necessary to control HIV replication.


Clinical and Vaccine Immunology | 2012

Decreased Specificity of an Assay for Recent Infection in HIV-1-Infected Patients on Highly Active Antiretroviral Treatment: Implications for Incidence Estimates

Antoine Chaillon; Stéphane Le Vu; Sylvie Brunet; Guillaume Gras; Frédéric Bastides; Louis Bernard; Laurence Meyer; Francis Barin

ABSTRACT The aim of this study was to estimate the rate of misclassification in treated HIV patients who initiated treatment at the chronic stage of HIV infection using an enzyme immunoassay (EIA) that discriminates between recent infection (RI; within 6 months) and established infection. The performance of EIA-RI was evaluated in 96 HIV-1 chronically infected patients on highly active antiretroviral therapy (HAART) with an undetectable viral load (VL) for at least 3 years. Demographic data, HIV-1 viral load, CD4+ T-cell count, viral subtype, and treatment duration were collected. The subset of misclassified patients was further analyzed using samples collected annually. The impact on incidence estimates was evaluated by simulation. The specificity in treated patients was significantly lower (70.8 to 77.1%) than that observed in untreated patients (93.3 to 99.3%, P < 0.001). Patients falsely classified as recently infected had been treated for a longer period and had longer-term viral suppression than those correctly classified. The loss of specificity of the test due to treatment may have a dramatic impact on the accuracy of the incidence estimates, with a major impact when HIV prevalence is high. The cross-sectional studies intended to derive HIV incidence must collect information on treatment or, alternatively, should include detection of antiretroviral drugs in blood specimens to rule out treated patients from the calculations.


Clinical Infectious Diseases | 2011

Chronic Q Fever: Relevance of Serology

Simon Sunder; Guillaume Gras; Frédéric Bastides; Claire De Gialluly; Patrick Choutet; Louis Bernard

To the Editor—We read with interest the recent paper on Q fever by Healy et al [1], which describes the results of initial and follow-up serologic analysis after an outbreak of Q fever, and the discrepancy in test results obtained from different reference laboratories. This article raises the problem of management of asymptomatic patients with a chronic serological profile (phase 1 serum level of immunoglobulin G [IgG],


Medicine | 2016

18F-FDG PET/CT as a central tool in the shift from chronic Q fever to Coxiella burnetii persistent focalized infection: A consecutive case series.

Carole Eldin; Cléa Melenotte; Matthieu Million; Serge Cammilleri; Albert Sotto; Antoine Elsendoorn; Franck Thuny; Hubert Lepidi; Thierry Weitten; Souad Assaad; Anissa Bouaziz; Claire Chapuzet; Guillaume Gras; Anne-Sophie Labussiere; Cécile Landais; Pascale Longuet; Agathe Masseau; Olivier Mundler; Didier Raoult

800 mg/dL). We conducted a retrospective analysis of 35 patients with chronic Q fever whose conditions were followed in our institution between 1996 and 2009, who had an initial (n 5 26) or secondary (postacute phase) (n 5 9) serological diagnosis of chronic Q fever. Of the 35 patients, 23 were asymptomatic, 9 had definite endocarditis (Duke criteria), 2 had hepatitis, and 1 had optical neuritis. The asymptomatic patients included 7 with possible cases of endocarditis, according to the Duke criteria (phase 1 IgG level,


Medicine | 2015

Nocardia Arthritis: 3 Cases and Literature Review.

Hélène Chaussade; David Lebeaux; Guillaume Gras; Emilie Catherinot; Blandine Rammaert; S. Poirée; Hervé Lécuyer; Valérie Zeller; Louis Bernard; Olivier Lortholary

800 mg/dL and valvular disease). Of the 16 (n 5 23 minus 7) asymptomatic patients with a chronic serological profile, 9 received no treatment; all 9 were healthy. Clinical and serological controls were conducted in 2010 for 7 of these patients: 5 had a healing serological profile and 2 had serological controls (follow-up ,1 year) that showed a regression of the phase 1 IgG or IgA titers.


International Journal of Infectious Diseases | 2017

Antibiotic therapy duration for prosthetic joint infections treated by Debridement and Implant Retention (DAIR): Similar long-term remission for 6 weeks as compared to 12 weeks

Hélène Chaussade; Ilker Uckay; Albert Vuagnat; J. Druon; Guillaume Gras; Philippe Rosset; Benjamin A. Lipsky; Louis Bernard

AbstractBecause Q fever is mostly diagnosed serologically, localizing a persistent focus of Coxiella burnetii infection can be challenging. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) could be an interesting tool in this context.We performed a retrospective study on patients diagnosed with C burnetii infection, who had undergone 18F-FDG PET/CT between 2009 and 2015. When positive 18F-FDG PET/CT results were obtained, we tried to determine if it changed the previous diagnosis by discovering or confirming a suspected focus of C burnetii infection.One hundred sixty-seven patients benefited from 18F-FDG PET/CT. The most frequent clinical subgroup before 18F-FDG PET/CT was patients with no identified focus of infection, despite high IgG1 serological titers (34%). For 59% (n = 99) of patients, a hypermetabolic focus was identified. For 62 patients (62.6%), the positive 18F-FDG PET/CT allowed the diagnosis to be changed. For 24 of them, (38.7%), a previously unsuspected focus of infection was discovered. Forty-two (42%) positive patients had more than 1 hypermetabolic focus. We observed 21 valvular foci, 34 vascular foci, and a high proportion of osteoarticular localizations (n = 21). We also observed lymphadenitis (n = 27), bone marrow hypermetabolism (n = 11), and 9 pulmonary localizations.We confirmed that18F-FDG PET/CT is a central tool in the diagnosis of C burnetii focalized persistent infection. We proposed new diagnostic scores for 2 main clinical entities identified using 18F-FDG PET/CT: osteoarticular persistent infections and lymphadenitis.


PLOS ONE | 2017

Pyogenic vertebral osteomyelitis of the elderly: Characteristics and outcomes

Johan Courjon; Adrien Lemaignen; Idir Ghout; Audrey Therby; Nadia Belmatoug; Aurélien Dinh; Guillaume Gras; Louis Bernard

Abstract Nocardia are Gram-positive filamentous bacteria responsible for infections ranging from opportunistic life-threatening disseminated diseases to chronic skin and soft-tissue infections. Even if virtually all organs can be infected, articular involvement is rare. Therefore, we report 3 recent cases and performed a literature review of cases of Nocardia arthritis in order to describe clinical features, therapeutic challenges, and outcome of these patients. Among 34 patients (31 in the literature plus our 3 cases), 21 (62%) were due to hematogenous dissemination, 9 (26%) were due to direct bacterial inoculation through the skin, and in 4 cases, the mechanism of infection was unknown. Four out of these 34 cases occurred on prosthetic joints. Whereas hematogenous infections mostly occurred in immunocompromised hosts (17 of 21, 81%), direct inoculation was mostly seen in immunocompetent patients. Eighty-two percent of patients (28 out of 34) received trimethoprim-sulfamethoxazole-containing regimens and median antibiotic treatment duration was 24 weeks (range, 12–120) for hematogenous infections and 12 weeks (range, 6–24) for direct inoculations. Outcome was favorable in 27 cases despite unsystematic surgical management (17 cases) without sequelae in 70% of the cases. Nocardia arthritis is rare but its management is complex and should rely on a combined approach with rheumatologist, infectious diseases expert, and surgeon.


AIDS | 2009

Late diagnosis and subsequent survival among HIV-infected truck drivers in the northwest of France: a retrospective study.

Guillaume Gras; L. Geffray; Jean-Jacques Parienti; Yazdan Yazdanpanah; Manuel Etienne; Jean-Luc Schmit; Renaud Verdon

BACKGROUND The required duration of antibiotic treatment for prosthetic joint infections (PJI) with debridement and retention of the implant (DAIR procedure) is unknown. METHODS Multicenter retrospective study emphasizing the duration of antibiotic therapy in patients treated with by DAIR. RESULTS We included 87 hip or knee PJI episodes in 87 patients from three university hospitals in France and Switzerland. All debridements were performed within 3 weeks of symptom onset. After a mean follow-up of 52.1 months, 60 patients with PJI (69%) remained in remission, with no significant difference between hip and knee cases (73.3% vs. 59.3%, 95% confidence interval (CI), 0.20-1.38), or between patients receiving 6 compared with 12 weeks of antibiotic treatment (70.5% vs.67.4%, 95%CI 0.27-2.10, p=0.60). Methicillin-resistant Staphylococcus aureus was isolated from 13.8% of infections and this was the only variable associated with a poorer outcome (remission in 41.7% vs. 73.3% for those with other pathogens, 95%CI 0.05-0.77, p=0.02). CONCLUSIONS In patients undergoing DAIR for hip or knee PJI, the likelihood of long-term remission was not significantly different for those receiving 6 versus 12 weeks of antibiotic therapy. Prospective randomized trials are required to confirm this observation.

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Louis Bernard

François Rabelais University

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Francis Barin

François Rabelais University

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Philippe Rosset

François Rabelais University

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E. Laurent

François Rabelais University

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Antoine Chaillon

François Rabelais University

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C. Hassen-Khodja

François Rabelais University

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Clotilde Allavena

François Rabelais University

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Emmanuel Rusch

François Rabelais University

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