Jenny Dahl Knudsen

Copenhagen University Hospital Hvidovre, Hvidovre, Capital Region, Denmark

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Publications (61)186.14 Total impact

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    ABSTRACT: The aim of the study was to investigate the molecular epidemiology of 87 third-generation cephalosporin-resistant Escherichia coli (3GC-R Ec) from bloodstream infections in Denmark from 2009. Sixty-eight of the 87 isolates were extended-spectrum beta-lactamase (ESBL) producers, whereas 17 isolates featured AmpC mutations only (without a coexpressed ESBL enzyme) and 2 isolates were producing CMY-22. The majority (82%) of the ESBL-producing isolates in our study were CTX-M-15 producers and primarily belonged to phylogroup B2 (54.4%) or D (23.5%). Further, one of the two CMY-22-producing isolates belonged to B2, whereas only few of the other AmpCs isolates belonged to B2 and D. Pulsed-field gel electrophoresis revealed that both clonal and nonclonal spread of 3GC-R Ec occurred. ST131 was detected in 50% of ESBL-producing isolates. The remaining ESBL-producing isolates belonged to 17 other sequence types (STs), including several other internationally spreading STs (e.g., ST10, ST69, and ST405). The majority (93%) of the ESBL-producing isolates and one of the CMY-22-producing isolates were multiresistant. In conclusion, 3GC-R in bacteriaemic E. coli in Denmark was mostly due to ESBL production, overexpression of AmpC, and to a lesser extent to plasmid-mediated AmpC. The worldwide disseminated CTX-M-15-ST131 was strongly represented in this collection of Danish, bacteriaemic E. coli isolates.
    Microbial drug resistance (Larchmont, N.Y.) 02/2014; · 1.99 Impact Factor
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    ABSTRACT: Enterococci currently account for approximately 10% of all bacteraemias, reflecting remarkable changes in their epidemiology. However, population-based data of enterococcal bacteraemia are scarce. A population-based cohort study comprised all patients with a first episode of Enterococcus faecalis or Enterococcus faecium bacteraemia in two Danish regions during 2006–2009. We used data collected prospectively during clinical microbiological counselling and hospital registry data. We determined the incidence of mono- and polymicrobial bacteraemia and assessed clinical and microbiological characteristics as predictors of 30-day mortality in monomicrobial bacteraemia by logistic regression analysis. We identified 1145 bacteraemic patients, 700 (61%) of whom had monomicrobial bacteraemia. The incidence was 19.6/100 000 person-years (13.0/100 000 person-years for E. faecalis and 6.6/100 000 person-years for E. faecium). The majority of bacteraemias were hospital-acquired (E. faecalis, 45.7%; E. faecium, 85.2%). Urinary tract and intra-abdominal infections were the predominant foci for the two species, respectively. Infective endocarditis (IE) accounted for 25% of patients with community-acquired E. faecalis bacteraemia. Thirty-day mortality was 21.4% in patients with E. faecalis and 34.6% in patients with E. faecium. Predictors of 30-day mortality included age, co-morbidity and hospital-acquired bacteraemia. In addition, intra-abdominal infection, unknown focus and high-level gentamicin resistance were predictors of mortality in E. faecalis patients. E. faecium was associated with increased risk of mortality compared with E. faecalis. The study emphasizes the importance of enterococci both in terms of incidence and prognosis. The frequency of IE in patients with E. faecalis bacteraemia emphasizes the importance of echocardiography, especially in community-acquired cases.
    Clinical Microbiology and Infection 02/2014; 20(2). · 4.58 Impact Factor
  • Jenny Dahl Knudsen, Stig Ejdrup Andersen
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    ABSTRACT: In response to a considerable increase in the infections caused by ESBL/AmpC-producing Klebsiella pneumonia in 2008, a multidisciplinary intervention, with a main focus on antimicrobial stewardship, was carried out at one university hospital. Four other hospitals were used as controls. Stringent guidelines for antimicrobial treatment and prophylaxis were disseminated throughout the intervention hospital; cephalosporins were restricted for prophylaxis use only, fluoroquinolones for empiric use in septic shock only, and carbapenems were selected for penicillin-allergic patients, infections due to ESBL/AmpC-producing and other resistant bacteria, in addition to their use in severe sepsis/septic shock. Piperacillin-tazobactam ± gentamicin was recommended for empiric treatments of most febrile conditions. The intervention also included education and guidance on infection control, as well as various other surveillances. Two year follow-up data on the incidence rates of patients with selected bacterial infections, outcomes, and antibiotic consumption were assessed, employing before-and-after analysis and segmented regression analysis of interrupted time series, using the other hospitals as controls. The intervention led to a sustained change in antimicrobial consumption, and the incidence of patients infected with ESBL-producing K. pneumoniae decreased significantly (p<0.001). The incidences of other hospital-associated infections also declined (p's<0.02), but piperacillin-tazobactam-resistant Pseudomonas aeruginosa and Enterococcus faecium infections increased (p's<0.033). In wards with high antimicrobial consumption, the patient gut carrier rate of ESBL-producing bacteria significantly decreased (p = 0.023). The unadjusted, all-cause 30-day mortality rates of K. pneumoniae and E. coli were unchanged over the four-year period, with similar results in all five hospitals. Although not statistically significant, the 30-day mortality rate of patients with ESBL-producing K. pneumoniae decreased, from 35% in 2008-2009, to 17% in 2010-2011. The two-year follow-up data indicated that this multidisciplinary intervention led to a statistically significant decrease in the incidence of ESBL/AmpC-resistant K. pneumoniae infections, as well as in the incidences of other typical hospital-associated bacterial infections.
    PLoS ONE 01/2014; 9(1):e86457. · 3.53 Impact Factor
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    ABSTRACT: Lethal outcomes can be expressed as a case fatality ratio (CFR) or as a mortality rate per 100,000 population per year (MR). Population surveillance for community-onset methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus bacteraemia was conducted in Canada, Australia, Sweden and Denmark to evaluate 30-day CFR and MR trends between 2000-2008. The CFR was 20.3% (MSSA 20.2%, MRSA 22.3%) and MR was 3.4 (MSSA 3.1, MRSA 0.3) per 100,000 per year. Although MSSA CFR case was stable the MSSA MR increased; MRSA CFR decreased while its MR remained low during the study. Community-onset S. aureus bacteraemia, particularly MSSA, is associated with major disease burden. This study highlights complementary information provided by evaluating both CFR and MR. This article is protected by copyright. All rights reserved.
    Clinical Microbiology and Infection 01/2014; · 4.58 Impact Factor
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    ABSTRACT: The Danish Collaborative Bacteraemia Network (DACOBAN) research database includes microbiological data obtained from positive blood cultures from a geographically and demographically well-defined population serviced by three clinical microbiology departments (1.7 million residents, 32% of the Danish population). The database also includes data on comorbidity from the Danish National Patient Registry, vital status from the Danish Civil Registration System, and clinical data on 31% of nonselected records in the database. Use of the unique civil registration number given to all Danish residents enables linkage to additional registries for specific research projects. The DACOBAN database is continuously updated, and it currently comprises 39,292 patients with 49,951 bacteremic episodes from 2000 through 2011. The database is part of an international network of population-based bacteremia registries from five developed countries on three continents. The main purpose of the DACOBAN database is to study surveillance, risk, and prognosis. Sex- and age-specific data on background populations enables the computation of incidence rates. In addition, the high number of patients facilitates studies of rare microorganisms. Thus far, studies on Staphylococcus aureus, enterococci, computer algorithms for the classification of bacteremic episodes, and prognosis and risk in relation to socioeconomic factors have been published.
    Clinical epidemiology. 01/2014; 6:301-8.
  • Jenny Dahl Knudsen, Niels Frimodt-Møller
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    ABSTRACT: Antibiotic treatment of elderly patients implies special problems because of higher probability of reduced renal or other organ function, and interactions with other medications. Elderly patients are more often previously hospitalised and treated with antibiotics or live in health-care institutions, and may be colonised with resistant microorganisms. It is crucial to sample for microbiological diagnostics before therapy. Adverse effects of antibiotics are seen more frequently with increasing age. Otherwise, the effect of antibiotics and durations of therapy is independent of patient age.
    Ugeskrift for laeger 11/2013; 175(47):2854-2857.
  • R R Laub, J D Knudsen
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    ABSTRACT: To optimize patient treatment and rational use of antimicrobials, it is important to provide fast information on findings in blood-cultures (BCs). The purpose of this study was to evaluate the impact of using peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) on positive BCs containing Gram-positive cocci in clusters to differentiate between Staphylococcus aureus (SA) and coagulase negative staphylococci (CoNS) on the prescribed antimicrobial therapy and on the number of contacts between microbiologist and clinician. All cases of positive BCs in our laboratory with SA or CoNS in the year 2011 were identified and the charts were reviewed retrospectively. The group of patients with BCs tested with PNA-FISH was compared to the group of patients with untested BCs. A total of 200 patients with SA and 725 patients with CoNS were included. The mean number of contacts was 0.82 when PNA-FISH showed CoNS and 1.39 when PNA-FISH was not done (p < 0.0001). More patients were recommended appropriate antimicrobial therapy for SA bacteraemia in the PNA-FISH group (98.0 %) than in the non-PNA-FISH group (89.4 %) (p = 0.025). The percentage treated with dicloxacillin was 29.6 in the PNA-FISH group, and 8.2 in the non-PNA-FISH group (p = 0.0003). The use of PNA-FISH on BCs in this study was associated with more appropriate and narrow spectrum antimicrobial therapy for patients with SA in an area with low prevalence of methicillin-resistant SA, and a lower number of contacts between clinical microbiologist and clinician about BCs with CoNS as contaminants.
    European Journal of Clinical Microbiology 10/2013; · 3.02 Impact Factor
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    ABSTRACT: The prevalence of urinary tract infections (UTIs) caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is increasing and the therapeutic options are limited, especially in primary care. Recent indications have suggested pivmecillinam to be a suitable option. Here, we evaluated the clinical and bacteriological effects of pivmecillinam in UTIs caused by ESBL-producing Enterobacteriaceae. We carried out a prospective follow-up of 39 patients diagnosed with UTI caused by ESBL-producing Enterobacteriaceae, initiated on pivmecillinam. The patients were from general practice (n = 29) or admitted to hospitals (n = 10) in the Copenhagen area, Denmark (n = 30) or Halland, Sweden (n = 9). Both patients and physicians were asked to complete a questionnaire on the pretreatment signs and symptoms. Patients were asked to send in two more urine samples for culture examination, together with questionnaires for clinical effect, 2-6 and 10-20 days, respectively, after end of treatment. Of the 39 patients included, 30 received a treatment regimen of 400 mg of pivmecillinam three times a day and 9 received 200 mg three times a day. All isolates were susceptible to mecillinam. The bacteriological cure rate was 79% (31/39); 80% (24/30) and 78% (7/9) for 400 and 200 mg three times a day, respectively. Relapse, i.e. ESBL-producing bacteria in the second control urine after previous bacteriological cure, was seen in five patients. Clinical cure was evaluable in 19 patients; 16 had a clinical effect (84%). Pivmecillinam was proven bacteriologically and clinically effective for treatment of lower UTIs caused by ESBL-producing Enterobacteriaceae.
    Journal of Antimicrobial Chemotherapy 10/2013; · 5.34 Impact Factor
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    ABSTRACT: The objective of the present study was to compare the efficacy of cefuroxime with that of dicloxacillin as definitive antimicrobial therapy in methicillin-susceptible Staphylococcus aureus bacteraemia (MS-SAB) using a Danish bacteraemia database, information on the indication for antimicrobial therapy, multivariate adjustment and propensity score (PS) matching. This was a retrospective cohort study. MS-SAB cases from 1 January 2006 to 31 December 2008 were included from a total of seven hospitals in the greater Copenhagen area and seven hospitals in the North Denmark Region. Information including demographics, antimicrobial therapy and clinical condition was obtained. The physician's note detailing the indication for starting empirical antimicrobial therapy was given special attention. Hazard ratios (HRs) and 95% CIs for 30 day and 90 day mortality were calculated using PS-adjusted Cox proportional hazards regression analyses. In addition, PS matching was performed. A total of 691 patients with MS-SAB received either dicloxacillin (n = 368) or cefuroxime (n = 323) as definitive antimicrobial therapy. Twenty-eight different indications for empirical antimicrobial therapy were identified and grouped into eight categories. There was no statistically significant difference in 30 day mortality between the two groups (HR 1.02, 95% CI 0.68-1.52). Definitive antimicrobial therapy with cefuroxime was associated with increased 90 day mortality in a PS-adjusted multivariate analysis (HR 1.43, 95% CI 1.03-1.98) and in the PS matching (OR 1.65, 95% CI 1.06-2.56). Antimicrobial therapy for an indication of 'severe infection' was independently associated with 90 day mortality (HR 1.97, 95% CI 1.19-3.28). Definitive antimicrobial therapy with cefuroxime was associated with significantly higher 90 day mortality than was dicloxacillin therapy in patients with MS-SAB.
    Journal of Antimicrobial Chemotherapy 09/2013; · 5.34 Impact Factor
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    ABSTRACT: In developed countries, invasive disease caused by non typhoidal Salmonella spp. is rare. Here we present a Danish case of Salmonella enterica serovar Enteritidis (S. Enteritidis) meningitis in an infant who had no underlying diseases. The child had had no known expositions, and the source of the infection was never identified. The chance of finding uncommon microorganisms as cause of invasive infections such as meningitis and the choice of initial empiric antimicrobial treatments is discussed.
    Ugeskrift for laeger 08/2013; 175(33):1872-1873.
  • International journal of antimicrobial agents 06/2013; · 3.03 Impact Factor
  • Stig Ejdrup Andersen, Jenny Dahl Knudsen
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    ABSTRACT: BACKGROUND: Bacteria-producing extended spectrum β-lactamase (ESBL) enzymes are resistant to commonly used antimicrobials. In 2008, routine monitoring revealed a clonal hospital outbreak of ESBL-producing Klebsiella pneumoniae (ESBL-KP). METHODS: At a 510-bed Danish university hospital, a multidisciplinary change project inspired by Kotter's Eight Steps of Change was designed. In addition to revision of antimicrobial guidelines and restriction of selected antimicrobials, the complex, managed, multi-faceted intervention comprised training and education, enhanced isolation precautions, and a series of actions to improve the infection control measures and standardise procedures across the hospital. A prospective interrupted time series design was used to analyse data collected at hospital level from January 2008 through December 2011. RESULTS: Though overall antimicrobial consumption remained unaffected, the intervention led to intended, immediate and sustained reduction in the use of cefuroxime, and an increase in the use of ertapenem, piperacillin/tazobactam and β-lactamase sensitive penicillin. Moreover, a postintervention reduction in the rate of ESBL-KP in diagnostic samples and in the incidence of ESBL-KP infections was observed. The intervention may also have reduced the need for isolation precautions and may have shortened each isolation period. CONCLUSIONS: The results indicate that an immediate and sustained change in the antimicrobial consumption and a decreasing rate of ESBL-KP are achievable through the application of a managed, multi-faceted intervention that does not require ongoing antibiotic stewardship.
    BMJ quality & safety 05/2013; · 2.39 Impact Factor
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    ABSTRACT: BACKGROUND: Little is known about the clinical presentation and outcome of pneumococcal lower respiratory tract infection (LRTI) without positive chest X-ray findings and blood cultures. We investigated the prognostic impact of a pulmonary infiltrate and bacteraemia on the clinical course of hospitalized patients with confirmed pneumococcal LRTI. METHODS: We studied a population-based multi-centre cohort of 705 adults hospitalized with LRTI and Streptococcus pneumoniae in LRT specimens or blood: 193 without pulmonary infiltrate or bacteraemia, 250 with X-ray confirmed pneumonia, and 262 with bacteraemia. We compared adverse outcomes in the three groups and used multiple regression analyses to adjust for differences in age, sex, comorbidity, and lifestyle factors. RESULTS: Patients with no infiltrate and no bacteraemia were of similar age but had more comorbidity than the other groups (Charlson index score >=1: no infiltrate and no bacteraemia 81% vs. infiltrate without bacteraemia 72% vs. bacteraemia 61%), smoked more tobacco, and had more respiratory symptoms. In contrast, patients with a pulmonary infiltrate or bacteraemia had more inflammation (median C-reactive protein: no infiltrate and no bacteraemia 82 mg/L vs. infiltrate without bacteraemia 163 mg/L vs. bacteraemia 316 mg/L) and higher acute disease severity scores. All adverse outcomes increased from patients with no infiltrate and no bacteraemia to those with an infiltrate and to those with bacteraemia: Length of hospital stay (5 vs. 6 vs. 8 days); intensive care admission (7% vs. 20% vs. 23%); pulmonary complications (1% vs. 5% vs. 14%); and 30-day mortality (5% vs. 11% vs. 21%). Compared with patients with no infiltrate and no bacteraemia, the adjusted 30-day mortality rate ratio was 1.9 (95% confidence interval (CI) 0.9-4.1) in patients with an infiltrate without bacteraemia and 4.1 (95% CI 2.0-8.5) in bacteraemia patients. Adjustment for acute disease severity and inflammatory markers weakened these associations. CONCLUSIONS: Hospitalization with confirmed pneumococcal LRTI is associated with substantial morbidity and mortality even without positive chest X-ray findings and blood cultures. Still, there is a clinically important outcome gradient from LRTI patients with pneumococcal isolation only to those with detected pulmonary infiltrate or bacteraemia which is partly mediated by higher acute disease severity and inflammation.
    BMC Infectious Diseases 05/2013; 13(1):197. · 3.03 Impact Factor
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    ABSTRACT: Significant changes in the management of fungaemia have occurred over the last decade with increased use of fluconazole prophylaxis, of empirical treatment and of echinocandins as first-line agents for documented disease. These changes may impact the epidemiology of fungaemia. We present nationwide data for Denmark from 2010 to 2011. A total of 1081 isolates from 1047 episodes were recorded in 995 patients. The numbers of patients, episodes and recovered isolates increased by 13.1%, 14.5% and 14.1%, respectively, from 2010 to 2011. The incidence rate was significantly higher in 2011 (10.05/100 000) than in 2010 (8.82/100 000), but remained constant in the age groups 0-79 years. The incidence rate was highest at the extremes of age and in males. Candida albicans accounted for 52.1% but declined during 2004-11 (p 0.0155). Candida glabrata accounted for 28% and increased during 2004-2011 (p <0.0001). Candida krusei, Candida tropicalis and Candida parapsilosis remained rare (3.3-4.2%). The species distribution changed with increasing age (fewer C. parapsilosis and more C. glabrata) and by study centre. Overall, the susceptibility rates were: amphotericin B 97.3%, anidulafungin 93.8%, fluconazole 66.7%, itraconazole 69.6%, posaconazole 64.2% and voriconazole 85.0%. Acquired echinocandin resistance was molecularly confirmed in three isolates. The use of systemic antifungals doubled over the last decade (2002-2011) (from 717 000 to 1 450 000 defined daily doses/year) of which the vast majority (96.9%) were azoles. The incidence of fungaemia continues to increase in Denmark and is associated with a decreasing proportion being susceptible to fluconazole. Changes in demography, higher incidence in the elderly and higher antifungal consumption can at least in part explain the changes.
    Clinical Microbiology and Infection 04/2013; · 4.58 Impact Factor
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    ABSTRACT: OBJECTIVES: Penicillin-susceptible Staphylococcus aureus isolates account for a fifth of cases of S. aureus bacteraemia (SAB) in Denmark, but little is known about treatment outcomes with penicillins or other antimicrobials. Here we compare penicillin, dicloxacillin and cefuroxime as definitive treatments in relation to 30 day mortality. METHODS: A retrospective chart review of 588 penicillin-susceptible S. aureus cases at five centres from January 1995 to December 2010. Data on demographics, antimicrobial treatment, clinical signs and symptoms, and mortality at day 30 were collected. Hazard ratios (HRs) with 95% CIs associated with mortality were modelled using propensity-score-adjusted Cox proportional hazards regression analysis. Propensity-score-matched case-control studies were carried out. RESULTS: Definitive therapy with cefuroxime was associated with an increased risk of 30 day mortality compared with penicillin (adjusted HR 2.54, 95% CI 1.49-4.32). Other variables that were statistically significantly associated with 30 day mortality included increasing age, disease severity and a primary respiratory focus. Osteomyelitis/arthritis was associated with a lower risk of death than were other secondary manifestations. Propensity-score-matched case-control studies confirmed an increased risk of 30 day mortality: cefuroxime treatment (39%) versus penicillin treatment (20%), P = 0.037; and cefuroxime treatment (38%) versus dicloxacillin treatment (10%), P = 0.004. CONCLUSIONS: Definitive therapy for penicillin-susceptible SAB with cefuroxime was associated with a significantly higher mortality than was seen with therapy with penicillin or dicloxacillin.
    Journal of Antimicrobial Chemotherapy 04/2013; · 5.34 Impact Factor
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    ABSTRACT: There is limited knowledge of serotypes that cause non-bacteremic pneumococcal pneumonia (NBP). Here we report serotypes, their associated disease potential and coverage of pneumococcal conjugate vaccines (PCV) in adults with NBP and compare these to bacteremic pneumonia (BP). Adults with pneumonia and Streptococcus pneumoniae isolated from the lower respiratory tract or blood were included 1 year in a population-based design in Denmark. Pneumonia was defined as a new infiltrate on chest radiograph in combination with clinical symptoms or elevated white blood count or plasma C-reactive protein. All isolates were serotyped using type-specific pneumococcal rabbit antisera. All values are medians with interquartile ranges. There were 272 cases of NBP and 192 cases of BP. Ninety-nine percent were hospitalized. NBP and BP cases were of comparable age and sex but NBP cases had more respiratory symptoms and less severe disease compared to BP cases. In total, 46 different serotypes were identified. Among NBP cases, 5 serotypes accounted for nearly a third of isolates. PCV10 and -13 types covered 17% (95% confidence interval (CI): 11-23%) and 34% (95% CI: 25-43%) of NBP isolates, respectively. In contrast, the five most frequent serotypes accounted for two-thirds of BP isolates. PCV10 and -13 types covered 39% (95% CI: 30-48%) and 64% (95% CI: 48-79) of BP isolates, respectively. More severe NBP disease was associated with infection with invasive serotypes while there was an inverse relationship for BP. Only a third of cases of adult non-bacteremic pneumococcal pneumonia would potentially be preventable with the use of PCV13 and just one sixth of cases with the use of PCV10 indicating that PCVs with increased valency are needed to increase vaccine coverage for NBP in adults. PCV13 could potentially prevent two-thirds of adult bacteremic pneumococcal pneumonia.
    PLoS ONE 01/2013; 8(8):e72743. · 3.53 Impact Factor
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    ABSTRACT: Background: Data are sparse on the clinical presentation and outcome for hospitalized patients with lower respiratory tract (LRT) infection and with pneumococci isolated from the LRT without pulmonary infiltrate or bacteremia. Methods: We conducted a population-based cohort study including all adults hospitalized during 1 Jan. – 31 Dec. 2011 at any hospital in the North Denmark Region with LRT infection symptoms and a pneumococcal isolate from the LRT (N=169) or the bloodstream (N=79). We compared clinical symptoms, laboratory measurements, and outcomes among 83 patients without pulmonary infiltrate (nP), 86 with an infiltrate (confirmed pneumonia) (P), and 79 with pneumococcal bacteremia (B) (of which 18 also had LRT isolates). Results: A number of risk factors were similarly prevalent in all groups, including age (medians nP 65 vs P 69 vs B 64 years), smoking (nP 55% vs P 50% vs B 44%) and alcohol overuse (nP 13% vs P 10% vs B 16%), whereas the fraction living in nursing homes or other institutions differed slightly (nP 2,5% vs P 4,5% vs B 7,5%). nP patients had a similar or higher number of clinical LRT infection symptoms, and more had fever = >38.5oC (72% in nP vs 50% in P vs 37% in B), whereas median C-reactive protein values were clearly lower (nP 71 vs P 183 vs B 297 mg/L). There was a clinical outcome gradient from patients with pneumococcal isolation only, over patients with X-ray confirmed pneumococcal pneumonia, to patients with pneumococcal bacteremia. Thus, length of hospital stay increased successively from median 5 days in nP patients to 8.5 days (P) and 11 days (B). Risk of intensive care admission was 16%, 28%, and 27%, respectively. In-hospital mortality increased from 6% in nP patients to 9% in P patients and 22% in B patients. After confounder adjustment by Cox regression, the RR of death was 1.34 (95% CI 0.43-4.21) in P vs nP patients and 3.83 (95% CI 1.39-10.59) in B vs nP patients. Conclusion: Even though the risk of adverse outcomes was higher in pneumococcal LRT infection with X-ray confirmed pneumonia or bacteremia, isolation of pneumococci from the LRT in hospitalized patients in Denmark was a marker of substantial clinical symptoms and in-hospital mortality.
    IDWeek 2012 Meeting of the Infectious Diseases Society of America; 10/2012
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    ABSTRACT: BACKGROUND: Information from blood cultures is utilized for infection control, public health surveillance, and clinical outcome research. This information can be enriched by physicians assessments of positive blood cultures, which are, however, often available from selected patient groups or pathogens only. The aim of this work was to determine whether patients with positive blood cultures can be classified effectively for outcome research in epidemiological studies by the use of administrative data and computer algorithms, taking physicians assessments as reference. METHODS: Physicians assessments of positive blood cultures were routinely recorded at two Danish hospitals from 2006 through 2008. The physicians assessments classified positive blood cultures as: a) contamination or bloodstream infection; b) bloodstream infection as mono- or polymicrobial; c) bloodstream infection as community- or hospital-onset; d) communityonset bloodstream infection as healthcare-associated or not. We applied the computer algorithms to data from laboratory databases and the Danish National Patient Registry to classify the same groups and compared these with the physicians assessments as reference episodes. For each classification, we tabulated episodes derived by the physicians assessment and the computer algorithm and compared 30-day mortality between concordant and discrepant groups with adjustment for age, gender, and comorbidity. RESULTS: Physicians derived 9,482 reference episodes from 21,705 positive blood cultures. The agreement between computer algorithms and physicians assessments was high for contamination vs. bloodstream infection (8,966/9,482 reference episodes [96.6%], Kappa = 0.83) and mono- vs. polymicrobial bloodstream infection (6,932/7,288 reference episodes [95.2%], Kappa = 0.76), but lower for community- vs. hospital-onset bloodstream infection (6,056/7,288 reference episodes [83.1%], Kappa = 0.57) and healthcare-association (3,032/4,740 reference episodes [64.0%], Kappa = 0.15). The 30-day mortality in the discrepant groups differed from the concordant groups as regards community- vs. hospitalonset, whereas there were no material differences within the other comparison groups. CONCLUSIONS: Using data from health administrative registries, we found high agreement between the computer algorithms and the physicians assessments as regards contamination vs. bloodstream infection and monomicrobial vs. polymicrobial bloodstream infection, whereas there was only moderate agreement between the computer algorithms and the physicians assessments concerning the place of onset. These results provide new information on the utility of computer algorithms derived from health administrative registries.
    BMC Medical Research Methodology 09/2012; 12(1):139. · 2.21 Impact Factor
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    ABSTRACT: Clin Microbiol Infect ABSTRACT: Although the epidemiology of Staphylococcus aureus bloodstream infection (BSI) has been changing, international comparisons are lacking. We sought to determine the incidence of S. aureus BSI and assess trends over time and by region. Population-based surveillance was conducted nationally in Finland and regionally in Canberra, Australia, western Sweden, and three areas in each of Canada and Denmark during 2000-2008. Incidence rates were age-standardized and gender-standardized to the EU 27-country 2007 population. During 83 million person-years of surveillance, 18 430 episodes of S. aureus BSI were identified. The overall annual incidence rate for S. aureus BSI was 26.1 per 100 000 population, and those for methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) were 24.2 and 1.9 per 100 000, respectively. Although the overall incidence of community-onset MSSA BSI (15.0 per 100 000) was relatively similar across regions, the incidence rates of hospital-onset MSSA (9.2 per 100 000), community-onset MRSA (1.0 per 100 000) and hospital-onset MRSA (0.8 per 100 000) BSI varied substantially. Whereas the overall incidence of S. aureus BSI did not increase over the study period, there was an increase in the incidence of MRSA BSI. Major changes in the occurrence of community-onset and hospital-onset MSSA and MRSA BSI occurred, but these varied significantly among regions, even within the same country. Although major changes in the epidemiology of community-onset and hospital-onset MSSA and MRSA BSIs are occurring, this multinational population-based study did not find that the overall incidence of S. aureus BSI is increasing.
    Clinical Microbiology and Infection 04/2012; · 4.58 Impact Factor
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    ABSTRACT: Spontaneous bacterial peritonitis is a common infection in cirrhosis, associated with a high mortality. Third-generation cephalosporins are recommended as first-line treatment. The aim was to evaluate the epidemiology of microbiological ascitic fluid findings and antimicrobial resistance in Denmark. All patients with cirrhosis and a positive ascitic fluid culture, at three university hospitals in the Copenhagen area during a 7-year period, were retrospectively evaluated. Patients with apparent secondary peritonitis were excluded from the study. One hundred and forty cases with 187 microbiological isolates were identified. The findings were: Gram-positive cocci, n = 86 (45.9%); Enterobacteriaceae, n = 59 (31.7%), with Escherichia coli identified in 31 cases; anaerobes, n = 14 (7.5%); yeast, n = 12 (6.4%); and cutaneous flora, n = 15 (8.0%). One case of Listeria monocytogenes was identified (0.5%). Overall antibiotic coverage was 57% for cephalosporins, 73% for piperacillin-tazobactam, and 72% for meropenem. Mortality rates in patients with isolates susceptible or resistant to the initial antibiotic treatment at 30 days follow-up were 35% and 55%, respectively (p = 0.017, Log-rank test). Almost half of the isolates were Gram-positive cocci, and as the overall antibiotic coverage with a cephalosporin was only 57%, and survival significantly dependent on whether the microbial etiology was susceptible to initial antibiotic treatment or not, a change of standard empiric antibiotic regime should be considered. Piperacillin-tazobactam could be a favorable choice.
    Scandinavian Journal of Gastroenterology 12/2011; 47(2):212-6. · 2.33 Impact Factor

Publication Stats

848 Citations
186.14 Total Impact Points

Institutions

  • 2006–2014
    • Copenhagen University Hospital Hvidovre
      • • Department of Clinical Microbiology
      • • Department of Infectious Diseases
      Hvidovre, Capital Region, Denmark
  • 2013
    • Odense University Hospital
      • Department of Clinical Microbiology
      Odense, South Denmark, Denmark
    • Bispebjerg Hospital, Copenhagen University
      • Department of Clinical Pharmacology
      København, Capital Region, Denmark
  • 2005–2013
    • Aarhus University Hospital
      • • Department of Clinical Epidemiology
      • • Department of Clinical Microbiology
      Aarhus, Central Jutland, Denmark
  • 2011
    • Roskilde University
      Roskilde, Zealand, Denmark
  • 1996–2010
    • Statens Serum Institut
      • Department of Microbiology and Infection Control
      København, Capital Region, Denmark
  • 2007
    • Næstved Hospital
      Нествед, Zealand, Denmark
  • 2000
    • Providence Portland Medical Center
      Portland, Oregon, United States
  • 1998
    • Erasmus Universiteit Rotterdam
      • Department of Medical Microbiology and Infectious Diseases
      Rotterdam, South Holland, Netherlands