Winfried V. Kern

Prof. Winfried V. Kern

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Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 October 2022 in BMJ
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RPRaphael S Peter
Raphael S Peter
ANAlexandra Nieters
Alexandra Nieters
HKHans-Georg Kräusslich
Hans-Georg Kräusslich
SBStefan O Brockmann
Stefan O Brockmann
SGSiri Göpel
Siri Göpel
WKWinfried V. Kern
Winfried V. Kern
Objectives To describe symptoms and symptom clusters of post-covid syndrome six to 12 months after acute infection, describe risk factors, and examine the association of symptom clusters with general health and working capacity. Design Population based, cross sectional study Setting Adults aged 18-65 years with confirmed SARS-CoV-2 infection between October 2020 and March 2021 notified to health authorities in four geographically defined regions in southern Germany. Participants 50 457 patients were invited to participate in the study, of whom 12 053 (24%) responded and 11 710 (58.8% (n=6881) female; mean age 44.1 years; 3.6% (412/11 602) previously admitted with covid-19; mean follow-up time 8.5 months) could be included in the analyses. Main outcome measures Symptom frequencies (six to 12 months after versus before acute infection), symptom severity and clustering, risk factors, and associations with general health recovery and working capacity. Results The symptom clusters fatigue (37.2% (4213/11 312), 95% confidence interval 36.4% to 38.1%) and neurocognitive impairment (31.3% (3561/11 361), 30.5% to 32.2%) contributed most to reduced health recovery and working capacity, but chest symptoms, anxiety/depression, headache/dizziness, and pain syndromes were also prevalent and relevant for working capacity, with some differences according to sex and age. Considering new symptoms with at least moderate impairment of daily life and ≤80% recovered general health or working capacity, the overall estimate for post-covid syndrome was 28.5% (3289/11 536, 27.7% to 29.3%) among participants or at least 6.5% (3289/50 457) in the infected adult population (assuming that all non-responders had completely recovered). The true value is likely to be between these estimates. Conclusions Despite the limitation of a low response rate and possible selection and recall biases, this study suggests a considerable burden of self-reported post-acute symptom clusters and possible sequelae, notably fatigue and neurocognitive impairment, six to 12 months after acute SARS-CoV-2 infection, even among young and middle aged adults after mild infection, with a substantial impact on general health and working capacity. Trial registration German registry of clinical studies DRKS 00027012.

23 January 2025 in PLOS Medicine
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RPRaphael S. Peter
Raphael S. Peter
ANAlexandra Nieters
Alexandra Nieters
SGSiri Göpel
Siri Göpel
UMUta Merle
Uta Merle
Jürgen Michael SteinackerJürgen Michael Steinacker
Jürgen Michael Steinacker
OGon behalf of the EPILOC Phase 2 Study Group
on behalf of the EPILOC Phase 2 Study Group
Background: Self-reported health problems following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are common and often include relatively non-specific complaints such as fatigue, exertional dyspnoea, concentration or memory disturbance and sleep problems. The long-term prognosis of such post-acute sequelae of COVID-19/post-COVID-19 syndrome (PCS) is unknown, and data finding and correlating organ dysfunction and pathology with self-reported symptoms in patients with non-recovery from PCS is scarce. We wanted to describe clinical characteristics and diagnostic findings among patients with PCS persisting for >1 year and assessed risk factors for PCS persistence versus improvement. Methods and findings: This nested population-based case-control study included subjects with PCS aged 18–65 years with (n = 982) and age- and sex-matched control subjects without PCS (n = 576) according to an earlier population-based questionnaire study (6–12 months after acute infection, phase 1) consenting to provide follow-up information and to undergo comprehensive outpatient assessment, including neurocognitive, cardiopulmonary exercise, and laboratory testing in four university health centres in southwestern Germany (phase 2, another 8.5 months [median, range 3–14 months] after phase 1). The mean age of the participants was 48 years, and 65% were female. At phase 2, 67.6% of the patients with PCS at phase 1 developed persistent PCS, whereas 78.5% of the recovered participants remained free of health problems related to PCS. Improvement among patients with earlier PCS was associated with mild acute index infection, previous full-time employment, educational status, and no specialist consultation and not attending a rehabilitation programme. The development of new symptoms related to PCS among participants initially recovered was associated with an intercurrent secondary SARS-CoV-2 infection and educational status. Patients with persistent PCS were less frequently never smokers (61.2% versus 75.7%), more often obese (30.2% versus 12.4%) with higher mean values for body mass index (BMI) and body fat, and had lower educational status (university entrance qualification 38.7% versus 61.5%) than participants with continued recovery. Fatigue/exhaustion, neurocognitive disturbance, chest symptoms/breathlessness and anxiety/depression/sleep problems remained the predominant symptom clusters. Exercise intolerance with post-exertional malaise (PEM) for >14 h and symptoms compatible with myalgic encephalomyelitis/chronic fatigue syndrome were reported by 35.6% and 11.6% of participants with persistent PCS patients, respectively. In analyses adjusted for sex-age class combinations, study centre and university entrance qualification, significant differences between participants with persistent PCS versus those with continued recovery were observed for performance in three different neurocognitive tests, scores for perceived stress, subjective cognitive disturbances, dysautonomia, depression and anxiety, sleep quality, fatigue and quality of life. In persistent PCS, handgrip strength (40.2 [95% confidence interval (CI) [39.4, 41.1]] versus 42.5 [95% CI [41.5, 43.6]] kg), maximal oxygen consumption (27.9 [95% CI [27.3, 28.4]] versus 31.0 [95% CI [30.3, 31.6]] ml/min/kg body weight) and ventilatory efficiency (minute ventilation/carbon dioxide production slope, 28.8 [95% CI [28.3, 29.2]] versus 27.1 [95% CI [26.6, 27.7]]) were significantly reduced relative to the control group of participants with continued recovery after adjustment for sex-age class combinations, study centre, education, BMI, smoking status and use of beta blocking agents. There were no differences in measures of systolic and diastolic cardiac function at rest, in the level of N-terminal brain natriuretic peptide blood levels or other laboratory measurements (including complement activity, markers of Epstein–Barr virus [EBV] reactivation, inflammatory and coagulation markers, serum levels of cortisol, adrenocorticotropic hormone and dehydroepiandrosterone sulfate). Screening for viral persistence (PCR in stool samples and SARS-CoV-2 spike antigen levels in plasma) in a subgroup of the patients with persistent PCS was negative. Sensitivity analyses (pre-existing illness/comorbidity, obesity, medical care of the index acute infection) revealed similar findings. Patients with persistent PCS and PEM reported more pain symptoms and had worse results in almost all tests. A limitation was that we had no objective information on exercise capacity and cognition before acute infection. In addition, we did not include patients unable to attend the outpatient clinic for whatever reason including severe illness, immobility or social deprivation or exclusion. Conclusions: In this study, we observed that the majority of working age patients with PCS did not recover in the second year of their illness. Patterns of reported symptoms remained essentially similar, non-specific and dominated by fatigue, exercise intolerance and cognitive complaints. Despite objective signs of cognitive deficits and reduced exercise capacity, there was no major pathology in laboratory investigations, and our findings do not support viral persistence, EBV reactivation, adrenal insufficiency or increased complement turnover as pathophysiologically relevant for persistent PCS. A history of PEM was associated with more severe symptoms and more objective signs of disease and might help stratify cases for disease severity.

10 January 2023 in Nature Communications
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SDSwapnil Prakash Doijad
Swapnil Prakash Doijad
NGNicolas Gisch
Nicolas Gisch
RFRenate Frantz
Renate Frantz
Bajarang Vasant KumbharBajarang Vasant Kumbhar
Bajarang Vasant Kumbhar
JFJane Falgenhauer
Jane Falgenhauer
TCTrinad Chakraborty
Trinad Chakraborty
Species within the Enterobacter cloacae complex (ECC) include globally important nosocomial pathogens. A three-year study of ECC in Germany identified Enterobacter xiangfangensis as the most common species (65.5%) detected, a result replicated by examining a global pool of 3246 isolates. Antibiotic resistance profiling revealed widespread resistance and heteroresistance to the antibiotic colistin and detected the mobile colistin resistance (mcr)−9 gene in 19.2% of all isolates. We show that resistance and heteroresistance properties depend on the chromosomal arnBCADTEF gene cassette whose products catalyze transfer of L-Ara4N to lipid A. Using comparative genomics, mutational analysis, and quantitative lipid A profiling we demonstrate that intrinsic lipid A modification levels are genospecies-dependent and governed by allelic variations in phoPQ and mgrB, that encode a two-component sensor-activator system and specific inhibitor peptide. By generating phoPQ chimeras and combining them with mgrB alleles, we show that interactions at the pH-sensing interface of the sensory histidine kinase phoQ dictate arnBCADTEF expression levels. To minimize therapeutic failures, we developed an assay that accurately detects colistin resistance levels for any ECC isolate.

8 August 2013 in BMC Infectious Diseases
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CTChristian Theilacker
Christian Theilacker
JHJürgen Held
Jürgen Held
LALudger Allering
Ludger Allering
PEPetra Emmerich
Petra Emmerich
Jonas Schmidt-ChanasitJonas Schmidt-Chanasit
Jonas Schmidt-Chanasit
MPMarcus Panning
Marcus Panning
Mayaro virus is endemic in South America and sporadic outbreaks have been described. It causes a dengue-like febrile illness accompanied by severe and long-lasting polyarthralgias. Outside endemic regions, however, the disease is not well known and can be misdiagnosed as dengue. International travellers are at risk to acquire Mayaro virus and due to increased worldwide travel infectious disease specialists need to be aware of such rare clinical entities.

21 December 2012 in Parasites & Vectors
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KSKatarina Stete
Katarina Stete
SKStefanie J. Krauth
Stefanie J. Krauth
JCJean T. Coulibaly
Jean T. Coulibaly
SKStefanie Knopp
Stefanie Knopp
JHJan Hattendorf
Jan Hattendorf
JUJürg Utzinger
Jürg Utzinger
Background: Praziquantel is the drug of choice in preventive chemotherapy targeting schistosomiasis. Increasing large-scale administration of praziquantel requires monitoring of drug efficacy to detect early signs of development of resistance. Standard protocols for drug efficacy monitoring are necessary. Here, we determined the optimal time point for praziquantel efficacy assessment against Schistosoma haematobium and studied the dynamics of infection parameters following treatment. Methods: Ninety school-aged children from south Côte d’Ivoire with a parasitologically confirmed S. haematobium infection were treated with a single oral dose of praziquantel (40 mg/kg) and followed up for 62 days post-treatment. Urine samples were collected on 23 schooldays during this period and were subjected to visual examination (macrohaematuria), urine filtration and microscopy (S. haematobium eggs) and reagent strip testing (microhaematuria, proteinuria and leukocyturia). Results: Observed cure and egg reduction rates were highly dependent on the time point post-treatment. Egg reduction rates were high (>97%) in weeks 3–9 post-treatment. Cure rates were highest in weeks 6 (92.9%) and 9 (95.0%) post-treatment. The prevalence of infection-associated parameters decreased after treatment, reaching a minimum of 2.4% in weeks 5 (proteinuria) and 7 (leukocyturia) post-treatment, and 16.3% at the end of week 8 (microhaematuria). Macrohaematuria disappeared between weeks 3 and 6 post-treatment. Conclusions: For monitoring praziquantel efficacy against S. haematobium, we recommend that the cure rate is assessed at week 6 post-treatment. The egg reduction rate can be evaluated earlier, from day 14 post-treatment onwards. Reagent strips are a useful additional tool for evaluating treatment outcomes in areas with high endemicity, preferably at weeks 5 and 6 post-treatment. The delayed decrease of microhaematuria confirms that lesions in the urinary tract persist longer than egg excretion post-treatment.

5 February 2013 in BMC Infectious Diseases
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MLMark van der Linden
Mark van der Linden
RRRalf René Reinert
Ralf René Reinert
WKWinfried V. Kern
Winfried V. Kern
MIMatthias Imöhl
Matthias Imöhl
This study presents an analysis of 159 serotype 19A isolates from IPD in children before and after the general recommendation for childhood pneumococcal conjugate vaccination in Germany in July 2006. Vaccination formulations used were PCV7, PCV10 (from April 2009) and PCV13 (from Dec. 2009, replacing PCV7).