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Dive into the research topics where Jan Fehr is active.

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Featured researches published by Jan Fehr.


The Lancet | 2014

Once-daily dolutegravir versus darunavir plus ritonavir in antiretroviral-naive adults with HIV-1 infection (FLAMINGO): 48 week results from the randomised open-label phase 3b study

Bonaventura Clotet; Judith Feinberg; Jan van Lunzen; Marie-Aude Khuong-Josses; Andrea Antinori; Irina Dumitru; Vadim Pokrovskiy; Jan Fehr; Roberto Ortiz; Michael S. Saag; Julia Harris; Clare Brennan; Tamio Fujiwara; Sherene Min

BACKGROUND Dolutegravir has been shown to be non-inferior to an integrase inhibitor and superior to a non-nucleoside reverse transcriptase inhibitor (NNRTI). In FLAMINGO, we compared dolutegravir with darunavir plus ritonavir in individuals naive for antiretroviral therapy. METHODS In this multicentre, open-label, phase 3b, non-inferiority study, HIV-1-infected antiretroviral therapy-naive adults with HIV-1 RNA concentration of 1000 copies per mL or more and no resistance at screening were randomly assigned (1:1) to receive either dolutegravir 50 mg once daily or darunavir 800 mg plus ritonavir 100 mg once daily, with investigator-selected tenofovir-emtricitabine or abacavir-lamivudine. Randomisation was stratified by screening HIV-1 RNA (≤100,000 or >100,000 copies per mL) and nucleoside reverse transcriptase inhibitor (NRTI) selection. The primary endpoint was the proportion of patients with HIV-1 RNA concentration lower than 50 copies per mL (Food and Drug Administration [FDA] snapshot algorithm) at week 48 with a 12% non-inferiority margin. This trial is registered with ClinicalTrials.gov, NCT01449929. FINDINGS Recruitment began on Oct 31, 2011, and was completed on May 24, 2012, in 64 research centres in nine countries worldwide. Of 595 patients screened, 484 patients were included in the analysis (242 in each group). At week 48, 217 (90%) patients receiving dolutegravir and 200 (83%) patients receiving darunavir plus ritonavir had HIV-1 RNA of less than 50 copies per mL (adjusted difference 7·1%, 95% CI 0·9-13·2), non-inferiority and on pre-specified secondary analysis dolutegravir was superior (p=0·025). Confirmed virological failure occurred in two (<1%) patients in each group; we recorded no treatment-emergent resistance in either group. Discontinuation due to adverse events or stopping criteria was less frequent for dolutegravir (four [2%] patients) than for darunavir plus ritonavir (ten [4%] patients) and contributed to the difference in response rates. The most commonly reported (≥10%) adverse events were diarrhoea (dolutegravir 41 [17%] patients vs darunavir plus ritonavir 70 [29%] patients), nausea (39 [16%] vs 43 [18%]), and headache (37 [15%] vs 24 [10%]). Patients receiving dolutegravir had significantly fewer low-density lipoprotein values of grade 2 or higher (11 [2%] vs 36 [7%]; p=0·0001). INTERPRETATION Once-daily dolutegravir was superior to once-daily darunavir plus ritonavir. Once-daily dolutegravir in combination with fixed-dose NRTIs represents an effective new treatment option for HIV-1-infected, treatment-naive patients. FUNDING ViiV Healthcare and Shionogi & Co.


The Journal of Infectious Diseases | 2013

Cobicistat versus ritonavir as a pharmacoenhancer of atazanavir plus emtricitabine/tenofovir disoproxil fumarate in treatment-naive HIV type 1-infected patients: week 48 results.

Joel E. Gallant; Ellen Koenig; Jaime Andrade-Villanueva; Ploenchan Chetchotisakd; Edwin DeJesus; Francisco Antunes; Keikawus Arastéh; Graeme Moyle; Giuliano Rizzardini; Jan Fehr; Ya-Pei Liu; Lijie Zhong; Christian Callebaut; Javier Szwarcberg; Martin S. Rhee; Andrew K. Cheng

BACKGROUND  Cobicistat (COBI) is a pharmacoenhancer with no antiretroviral activity in vitro. METHODS  An international, randomized, double-blind, double-dummy, active-controlled trial was conducted to evaluate the efficacy and safety of COBI versus ritonavir (RTV) as a pharmacoenhancer of atazanavir (ATV) in combination with emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) in treatment-naive patients. The primary end point was a human immunodeficiency virus type 1 (HIV-1) RNA load of <50 copies/mL at week 48 by the Food and Drug Administration snapshot algorithm; the noninferiority margin was 12%. RESULTS  A total of 692 patients were randomly assigned to a treatment arm and received study drug (344 in the COBI group vs 348 in the RTV group). At week 48, virologic success was achieved in 85% of COBI recipients and 87% of RTV recipients (difference, -2.2% [95% confidence interval, -7.4% to 3.0%]); among patients with a baseline HIV-1 RNA load of >100 000 copies/mL, rates were similar (86% vs 86%). Similar percentages of patients in both groups had serious adverse events (10% of COBI recipients vs 7% of RTV recipients) and adverse events leading to discontinuation of treatment with the study drug (7% vs 7%). Median increases in the serum creatinine level were 0.13 and 0.09 mg/dL, respectively, for COBI and RTV recipients. CONCLUSIONS  COBI was noninferior to RTV in combination with ATV plus FTC/TDF at week 48. Both regimens achieved high rates of virologic success. Safety and tolerability profiles of the 2 regimens were comparable. Once-daily COBI is a safe and effective pharmacoenhancer of the protease inhibitor ATV.


Emerging Infectious Diseases | 2010

Septicemia Caused by Tick-borne Bacterial Pathogen Candidatus Neoehrlichia mikurensis

Jan Fehr; Guido V. Bloemberg; Claudia Ritter; Michael Hombach; Thomas F. Lüscher; Rainer Weber; Peter M. Keller

We have repeatedly detected Candidatus Neoehrlichia mikurensis, a bacterium first described in Rattus norvegicus rats and Ixodes ovatus ticks in Japan in 2004 in the blood of a 61-year-old man with signs of septicemia by 16S rRNA and groEL gene PCR. After 6 weeks of therapy with doxycycline and rifampin, the patient recovered.


Journal of Antimicrobial Chemotherapy | 2008

Antiretroviral therapy of late presenters with advanced HIV disease

Manuel Battegay; Jan Fehr; Ursula Flückiger; Luigia Elzi

Potent antiretroviral therapy (ART) has dramatically improved the prognosis of HIV-1-infected individuals. However, 10% to 30% of patients in Western countries still present late for care, when CD4 T cells are below 200 cells/mm(3) and symptomatic HIV disease has occurred. Clinical considerations for advanced HIV disease are paramount as morbidity and mortality are directly correlated with a low initial CD4 T cell count, which is commonly associated with the simultaneous occurrence of co-morbidities, particularly opportunistic infections. Upon start of ART, the clinical entity of immune reconstitution inflammatory syndrome may occur and, in this context, raise the question of early versus delayed ART in patients treated for opportunistic infections. Recent data clearly indicate that an earlier start of ART is warranted in this latter situation. Guidelines for specific antiretroviral treatment for late-presenting patients are lacking. Knowledge about drug-drug interactions and co-morbidities should guide treatment choices and influence the clinical management and monitoring of drug-related side effects and interactions. Importantly, the outlook of patients who present late is very much dependent upon the initial response to ART. Nevertheless, even if optimal response to treatment has been achieved, long-term prognosis may be impaired in patients who initially presented with advanced HIV disease. We encourage physicians to perform HIV testing more frequently in order to detect HIV-infected individuals in time.


Antimicrobial Agents and Chemotherapy | 2012

Effect of mutation and genetic background on drug resistance in Mycobacterium tuberculosis.

Lukas Fenner; Matthias Egger; Thomas Bodmer; Ekkehardt Altpeter; Marcel Zwahlen; Katia Jaton; Gaby E. Pfyffer; Sonia Borrell; Olivier Dubuis; Thomas Bruderer; Hans H Siegrist; Hansjakob Furrer; Alexandra Calmy; Jan Fehr; Jesica Mazza Stalder; Béatrice Alice Bescher Ninet; Erik C. Böttger; Sebastien Gagneux

ABSTRACT Bacterial factors may contribute to the global emergence and spread of drug-resistant tuberculosis (TB). Only a few studies have reported on the interactions between different bacterial factors. We studied drug-resistant Mycobacterium tuberculosis isolates from a nationwide study conducted from 2000 to 2008 in Switzerland. We determined quantitative drug resistance levels of first-line drugs by using Bactec MGIT-960 and drug resistance genotypes by sequencing the hot-spot regions of the relevant genes. We determined recent transmission by molecular methods and collected clinical data. Overall, we analyzed 158 isolates that were resistant to isoniazid, rifampin, or ethambutol, 48 (30.4%) of which were multidrug resistant. Among 154 isoniazid-resistant strains, katG mutations were associated with high-level and inhA promoter mutations with low-level drug resistance. Only katG(S315T) (65.6% of all isoniazid-resistant strains) and inhA promoter −15C/T (22.7%) were found in molecular clusters. M. tuberculosis lineage 2 (includes Beijing genotype) was associated with any drug resistance (adjusted odds ratio [OR], 3.0; 95% confidence interval [CI], 1.7 to 5.6; P < 0.0001). Lineage 1 was associated with inhA promoter −15C/T mutations (OR, 6.4; 95% CI, 2.0 to 20.7; P = 0.002). We found that the genetic strain background influences the level of isoniazid resistance conveyed by particular mutations (interaction tests of drug resistance mutations across all lineages; P < 0.0001). In conclusion, M. tuberculosis drug resistance mutations were associated with various levels of drug resistance and transmission, and M. tuberculosis lineages were associated with particular drug resistance-conferring mutations and phenotypic drug resistance. Our study also supports a role for epistatic interactions between different drug resistance mutations and strain genetic backgrounds in M. tuberculosis drug resistance.


British Journal of Cancer | 2012

Lung cancer in the Swiss HIV Cohort Study: role of smoking, immunodeficiency and pulmonary infection.

Gary M. Clifford; Mauro Lise; Silvia Franceschi; Matthias Egger; Christine Bouchardy; D Korol; Fabio Levi; Silvia Ess; Gernot Jundt; Gilles Wandeler; Jan Fehr; Patrick Schmid; Manuel Battegay; Enos Bernasconi; Matthias Cavassini; Alexandra Calmy; Olivia Keiser; Franziska Schöni-Affolter

Background:Immunodeficiency and AIDS-related pulmonary infections have been suggested as independent causes of lung cancer among HIV-infected persons, in addition to smoking.Methods:A total of 68 lung cancers were identified in the Swiss HIV Cohort Study (SHCS) or through linkage with Swiss Cancer Registries (1985–2010), and were individually matched to 337 controls by centre, gender, HIV-transmission category, age and calendar period. Odds ratios (ORs) were estimated by conditional logistic regression.Results:Overall, 96.2% of lung cancers and 72.9% of controls were ever smokers, confirming the high prevalence of smoking and its strong association with lung cancer (OR for current vs never=14.4, 95% confidence interval (95% CI): 3.36–62.1). No significant associations were observed between CD4+ cell count and lung cancer, neither when measured within 1 year (OR for <200 vs ⩾500=1.21, 95% CI: 0.49–2.96) nor further back in time, before lung cancer diagnosis. Combined antiretroviral therapy was not significantly associated with lung cancer (OR for ever vs never=0.67, 95% CI: 0.29–1.52), and nor was a history of AIDS with (OR=0.49, 95% CI: 0.19–1.28) or without (OR=0.53, 95% CI: 0.24–1.18) pulmonary involvement.Conclusion:Lung cancer in the SHCS does not seem to be clearly associated with immunodeficiency or AIDS-related pulmonary disease, but seems to be attributable to heavy smoking.


Clinical Microbiology and Infection | 2014

Candida species distribution and antifungal susceptibility testing according to European Committee on Antimicrobial Susceptibility Testing and new vs. old Clinical and Laboratory Standards Institute clinical breakpoints: a 6-year prospective candidaemia survey from the fungal infection network of Switzerland

Christina Orasch; Oscar Marchetti; Jorge Garbino; Jacques Schrenzel; Stefan Zimmerli; Konrad Mühlethaler; G. Pfyffer; Christian Ruef; Jan Fehr; Reinhard Zbinden; Thierry Calandra; Jacques Bille

We analyzed the species distribution of Candida blood isolates (CBIs), prospectively collected between 2004 and 2009 within FUNGINOS, and compared their antifungal susceptibility according to clinical breakpoints defined by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in 2013, and the Clinical and Laboratory Standards Institute (CLSI) in 2008 (old CLSI breakpoints) and 2012 (new CLSI breakpoints). CBIs were tested for susceptiblity to fluconazole, voriconazole and caspofungin by microtitre broth dilution (Sensititre® YeastOne™ test panel). Of 1090 CBIs, 675 (61.9%) were C. albicans, 191 (17.5%) C. glabrata, 64 (5.9%) C. tropicalis, 59 (5.4%) C. parapsilosis, 33 (3%) C. dubliniensis, 22 (2%) C. krusei and 46 (4.2%) rare Candida species. Independently of the breakpoints applied, C. albicans was almost uniformly (>98%) susceptible to all three antifungal agents. In contrast, the proportions of fluconazole- and voriconazole-susceptible C. tropicalis and F-susceptible C. parapsilosis were lower according to EUCAST/new CLSI breakpoints than to the old CLSI breakpoints. For caspofungin, non-susceptibility occurred mainly in C. krusei (63.3%) and C. glabrata (9.4%). Nine isolates (five C. tropicalis, three C. albicans and one C. parapsilosis) were cross-resistant to azoles according to EUCAST breakpoints, compared with three isolates (two C. albicans and one C. tropicalis) according to new and two (2 C. albicans) according to old CLSI breakpoints. Four species (C. albicans, C. glabrata, C. tropicalis and C. parapsilosis) represented >90% of all CBIs. In vitro resistance to fluconazole, voriconazole and caspofungin was rare among C. albicans, but an increase of non-susceptibile isolates was observed among C. tropicalis/C. parapsilosis for the azoles and C. glabrata/C. krusei for caspofungin according to EUCAST and new CLSI breakpoints compared with old CLSI breakpoints.


Clinical Infectious Diseases | 2014

Treatment-Naive Individuals Are the Major Source of Transmitted HIV-1 Drug Resistance in Men Who Have Sex With Men in the Swiss HIV Cohort Study

Sara M. Drescher; Viktor von Wyl; Wan-Lin Yang; Jürg Böni; Sabine Yerly; Cyril Shah; Vincent Aubert; Thomas Klimkait; Patrick Taffé; Hansjakob Furrer; Manuel Battegay; Juan Ambrosioni; Matthias Cavassini; Enos Bernasconi; Pietro Vernazza; Bruno Ledergerber; Huldrych F. Günthard; Roger D. Kouyos; V. Aubert; J. Barth; M. Battegay; E Bernasconi; J Böni; H C Bucher; C. Burton-Jeangros; A Calmy; Matthias Egger; L Elzi; Jan Fehr; Jacques Fellay

BACKGROUND Human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) and thus represents an important public health concern. Typically, sources of TDR remain unknown, but they can be characterized with molecular epidemiologic approaches. We used the highly representative Swiss HIV Cohort Study (SHCS) and linked drug resistance database (SHCS-DRDB) to analyze sources of TDR. METHODS ART-naive men who have sex with men with infection date estimates between 1996 and 2009 were chosen for surveillance of TDR in HIV-1 subtype B (N = 1674), as the SHCS-DRDB contains pre-ART genotypic resistance tests for >69% of this surveillance population. A phylogeny was inferred using pol sequences from surveillance patients and all subtype B sequences from the SHCS-DRDB (6934 additional patients). Potential sources of TDR were identified based on phylogenetic clustering, shared resistance mutations, genetic distance, and estimated infection dates. RESULTS One hundred forty of 1674 (8.4%) surveillance patients carried virus with TDR; 86 of 140 (61.4%) were assigned to clusters. Potential sources of TDR were found for 50 of 86 (58.1%) of these patients. ART-naive patients constitute 56 of 66 (84.8%) potential sources and were significantly overrepresented among sources (odds ratio, 6.43 [95% confidence interval, 3.22-12.82]; P < .001). Particularly large transmission clusters were observed for the L90M mutation, and the spread of L90M continued even after the near cessation of antiretroviral use selecting for that mutation. Three clusters showed evidence of reversion of K103N or T215Y/F. CONCLUSIONS Many individuals harboring viral TDR belonged to transmission clusters with other Swiss patients, indicating substantial domestic transmission of TDR in Switzerland. Most TDR in clusters could be linked to sources, indicating good surveillance of TDR in the SHCS-DRDB. Most TDR sources were ART naive. This, and the presence of long TDR transmission chains, suggests that resistance mutations are frequently transmitted among untreated individuals, highlighting the importance of early diagnosis and treatment.


Infection Control and Hospital Epidemiology | 2006

Risk Factors for Surgical Site Infection in a Tanzanian District Hospital: A Challenge for the Traditional National Nosocomial Infections Surveillance System Index

Jan Fehr; Christoph Hatz; Isaac Soka; Patience Kibatala; Honorathy Urassa; Thomas J. Smith; Hassan Mshinda; Reno Frei; Andreas F. Widmer

The incidence of surgical site infections (SSIs) was 24% in a district hospital in Tanzania. Wound classification was not an independent risk factor for SSI, indicating that risk scores developed in industrialized countries may require adjustments for nonindustrialized countries. The National Nosocomial Infections Surveillance system score required adjustments to reliably predict SSI, probably to account for improper hygiene and the lack of adjustment for the duration of surgery (defined as the 75th percentile of the duration for each type of operative procedure) to reflect local circumstances. Multidrug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus and gram-negative pathogens expressing broad-spectrum beta-lactamases, have already emerged.


Hiv Medicine | 2009

Liver enzyme elevation after lamivudine withdrawal in HIV–hepatitis B virus co‐infected patients: the Swiss HIV Cohort Study

C. Bellini; Olivia Keiser; J-P Chave; J‐M Evison; Jan Fehr; L Kaiser; Rainer Weber; P. Vernazza; Enos Bernasconi; Amalio Telenti; Matthias Cavassini

The principal causes of liver enzyme elevation among HIV–hepatitis B virus (HBV) co‐infected patients are the hepatotoxic effects of antiretroviral therapy (ART), alcohol abuse, ART‐induced immune reconstitution and the exacerbation of chronic HBV infection.

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Patrick Schmid

University of St. Gallen

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