| 1. |
- Bjarnason, A., et al.
(författare)
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Incidence, etiology, and outcomes of community-acquired pneumonia: A population-based study
- 2018
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Ingår i: Open Forum Infectious Diseases. - : Oxford University Press (OUP). - 2328-8957. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Background. The microbial etiology of community-acquired pneumonia (CAP) is often unclear in clinical practice, and previous studies have produced variable results. Population-based studies examining etiology and incidence are lacking. This study examined the incidence and etiology of CAP requiring hospitalization in a population-based cohort as well as risk factors and outcomes for specific etiologies. Methods. Consecutive admissions due to CAP in Reykjavik, Iceland were studied. Etiologic testing was performed with cultures, urine-antigen detection, and polymerase chain reaction analysis of airway samples. Outcomes were length of stay, intensive care unit admission, assisted ventilation, and mortality. Results. The inclusion rate was 95%. The incidence of CAP requiring hospitalization was 20.6 cases per 10 000 adults/year. A potential pathogen was detected in 52% (164 of 310) of admissions and in 74% (43 of 58) with complete sample sets. Streptococcus pneumoniae was the most common pathogen (61 of 310, 20%; incidence: 4.1/10 000). Viruses were identified in 15% (47 of 310; incidence: 3.1/10 000), Mycoplasma pneumoniae were identified in 12% (36 of 310; incidence: 2.4/10 000), and multiple pathogens were identified in 10% (30 of 310; incidence: 2.0/10 000). Recent antimicrobial therapy was associated with increased detection of M pneumoniae (P ≤ .001), whereas a lack of recent antimicrobial therapy was associated with increased detection of S pneumoniae (P = .02). Symptoms and outcomes were similar irrespective of microbial etiology. Conclusions. Pneumococci, M pneumoniae, and viruses are the most common pathogens associated with CAP requiring hospital admission, and they all have a similar incidence that increases with age. Symptoms do not correlate with specific agents, and outcomes are similar irrespective of pathogens identified. © The Author(s) 2018.
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| 2. |
- Bjarnason, A, et al.
(författare)
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Utility of oropharyngeal real-time PCR for S. pneumoniae and H. influenzae for diagnosis of pneumonia in adults.
- 2017
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Ingår i: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. - : Springer Science and Business Media LLC. - 1435-4373. ; 36:3, s. 529-536
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Tidskriftsartikel (refereegranskat)abstract
- A lack of sensitive tests and difficulties obtaining representative samples contribute to the challenge in identifying etiology in pneumonia. Upper respiratory tract swabs can be easily collected and analyzed with real-time PCR (rtPCR). Common pathogens such as S. pneumoniae and H. influenzae can both colonize and infect the respiratory tract, complicating the interpretation of positive results. Oropharyngeal swabs were collected (n = 239) prospectively from adults admitted to hospital with pneumonia. Analysis with rtPCR targeting S. pneumoniae and H. influenzae was performed and results compared with sputum cultures, blood cultures, and urine antigen testing for S. pneumoniae. Different Ct cutoff values were applied to positive tests to discern colonization from infection. Comparing rtPCR with conventional testing for S. pneumoniae in patients with all tests available (n = 57) resulted in: sensitivity 87 %, specificity 79 %, PPV 59 % and NPV 94 %, and for H. influenzae (n = 67): sensitivity 75 %, specificity 80 %, PPV 45 % and NPV 94 %. When patients with prior antimicrobial exposure were excluded sensitivity improved: 92 % for S. pneumoniae and 80 % for H. influenzae. Receiver operating characteristic curve analysis demonstrated for S. pneumoniae: AUC = 0.65 (95 % CI 0.51-0.80) and for H. influenzae: AUC = 0.86 (95 % CI 0.72-1.00). Analysis of oropharyngeal swabs using rtPCR proved both reasonably sensitive and specific for diagnosing pneumonia caused by S. pneumoniae and H. influenzae. This method may be a useful diagnostic adjunct to other methods and of special value in patients unable to provide representative lower airway samples.
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| 3. |
- Bjursten, Henrik, et al.
(författare)
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S100B Profiles and Cognitive Function at High Altitude
- 2010
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Ingår i: High Altitude Medicine & Biology. - : Mary Ann Liebert Inc. - 1527-0297 .- 1557-8682. ; 11:1, s. 31-38
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Tidskriftsartikel (refereegranskat)abstract
- Bjursten, Henrik, Per Ederoth, Engilbert Sigurdsson, Magnus Gottfredsson, Ingvar Syk, Orri Einarsson, and Tomas Gudbjartsson. S100B profiles and cognitive function at high altitude. High Alt. Med. Biol. 11:31-38, 2010.-Exposure to high altitude can lead to acute mountain sickness (AMS) and high altitude cerebral edema (HACE). In this study we investigated the effect of high altitude on neurocognitive function and S100B release. Increased S100B release has been hypothesized to signify a loss of integrity in the blood-brain barrier (BBB). Seven healthy volunteers trekked to Capanna Regina Margherita (4554 m above sea level) in the Monte Rosa massif. During ascent and descent, five test events were undertaken; participants underwent neurocognitive testing, Lake Louise scoring (LLS), and blood sampling to measure levels of S100B. The blood tests revealed that S100B levels increased 42% to 122% from baseline, and mean LLS increased from 0.57 to 2.57. A significant correlation was observed between both S100B levels and LLS and S100B and some neurocognitive scores. The study indicates that S100B can be released by a mild hypoxia during AMS. Moreover, an observed correlation between S100B and a lower score on neurocognitive tests suggests that the pathogenetic mechanisms may be linked. The study indicates that a decline in cognitive function is associated with symptoms of AMS.
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| 4. |
- Knudsen, Jenny Dahl, et al.
(författare)
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Selection of Resistant Streptococcus pneumoniae during Penicillin Treatment In Vitro and in Three Animal Models.
- 2003
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Ingår i: Antimicrobial Agents and Chemotherapy. - 1098-6596. ; 47:8, s. 2499-2506
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Tidskriftsartikel (refereegranskat)abstract
- Pharmacokinetic (PK) and pharmacodynamic (PD) properties for the selection of resistant pneumococci were studied by using three strains of the same serotype (6B) for mixed-culture infection in time-kill experiments in vitro and in three different animal models, the mouse peritonitis, the mouse thigh, and the rabbit tissue cage models. Treatment regimens with penicillin were designed to give a wide range of T>MICs, the amounts of time for which the drug concentrations in serum were above the MIC. The mixed culture of the three pneumococcal strains, 107 CFU of strain A (MIC of penicillin, 0.016 µg/ml; erythromycin resistant)/ml, 106 CFU of strain B (MIC of penicillin, 0.25 µg/ml)/ml, and 105 CFU of strain C (MIC of penicillin, 4 µg/ml)/ml, was used in the two mouse models, and a mixture of 105 CFU of strain A/ml, 104 CFU of strain B/ml, and 103 CFU of strain C/ml was used in the rabbit tissue cage model. During the different treatment regimens, the differences in numbers of CFU between treated and control animals were calculated to measure the efficacies of the regimens. Selective media with erythromycin or different penicillin concentrations were used to quantify the strains separately. The efficacies of penicillin in vitro were similar when individual strains or mixed cultures were studied. The eradication of the bacteria, independent of the susceptibility of the strain or strains or the presence of the strains in a mixture or on their own, followed the well-known PK and PD rules for treatment with ß-lactams: a maximum efficacy was seen when the T>MIC was >40 to 50% of the observation time and the ratio of the maximum concentration of the drug in serum to the MIC was >10. It was possible in all three models to select for the less-susceptible strains by using insufficient treatments. In the rabbit tissue cage model, a regrowth of pneumococci was observed; in the mouse thigh model, the ratio between the different strains changed in favor of the less-susceptible strains; and in the mouse peritonitis model, the susceptible strain disappeared and was overgrown by the less-susceptible strains. These findings with the experimental infection models confirm the importance of eradicating all the bacteria taking part in the infectious process in order to avoid selection of resistant clones.
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| 5. |
- Lybeck, Charlotte, 1979-
(författare)
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Towards the elimination of hepatitis C : identifying the infected population, and remaining hepatitis C related risks after successful treatment
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chronic Hepatitis C virus (HCV) infection can lead to liver fibrosis and cirrhosis with increased risk of hepatocellular carcinoma (HCC) and liver failure. The World Health Organisation (WHO) has set a goal to eliminate viral hepatitis as a global health threat by 2030. To reach this goal for HCV we need to prevent new infections and identify and treat the infected population. Individuals with pre-treatment cirrhosis still have an elevated risk for HCC after HCV cure. This thesis aims to assess the health outcomes after cured HCV infection, study HCV prevalence and find a way to identify undiagnosed infections.In Paper I, 97 patients were followed through clinical visits (n=54) or through national registers (n=43) to study the long-term outcomes after cure from HCV and to assess the presence and impact of occult HCV infection (OCI). Three non-cirrhotic patients were diagnosed with HCC 8-11 years after HCV cure. Two patients had OCI at 8-9 years after cure. They had liver fibrosis stage 2, but no association with HCC. In Paper II, pregnant women (n=4,108) and partners (n=1,027) at antenatal clinics in southern Stockholm and Örebro County were tested for HCV and interviewed about risk factors to assess prevalence and evaluate screening strategies to identify undiagnosed infections. Anti-HCV prevalence was 0.7% and 0.4% were viraemic. The most effective risk factor-based screening was to ask for drug use, country of birth, and having a partner with HCV. Paper III presents a nationwide register study of the risk of extrahepatic cancer (EHC) the first 3 years after HCV treatment with direct acting antiviral (DAAs). We compared 4,013 DAA-treated, with 3,071 interferon-treated and 12,601 untreated patients. No increased risk for EHC was found after adjustments for age and comorbidities. An increased EHC risk in DAA-treated compared with general population was seen. Paper IV presents a register based study of the risk of HCC and association with pre-treatment liver stiffness measurement (LSM) in 7,227 HCV infected patients cured by DAAs. We found that pre-treatment LSM values correlated well with HCC risk. The incidence rate for patients with LSM values ≥12.5 kPa and <12.5 kPa was 1.6 and 0.15/100 person years, respectively.To conclude, cured HCV infection usually leads to regression of fibrosis. The DAAs are safe and highly effective against HCV. However, the HCC risk remains elevated for many years after cure in cirrhotic and sometimes in non-cirrhotic patients. Furthermore, HCV screening of pregnant women and partners is useful to identify patients who would benefit from therapy.
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| 6. |
- Möller, Vidar, et al.
(författare)
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Antibiotic resistance among major pathogens compared to hospital treatment guidelines and antibiotic use in Nordic hospitals 2010-2018
- 2021
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Ingår i: Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 2374-4243. ; 53:8, s. 607-618
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Tidskriftsartikel (refereegranskat)abstract
- Background The Nordic countries have comparable nationwide antibiotic resistance surveillance systems and individual antibiotic stewardship programmes. The aim of this study was to assess antibiotic resistance among major pathogens in relation to practice guidelines for hospital antibiotic treatment and antibiotic use in Nordic countries 2010-2018. Methods Antibiotic resistance among invasive isolates from 2010-2018 and aggregated antibiotic use were obtained from the European Centre for Disease Prevention and Control. Hospital practice guidelines were obtained from national or regional guidelines. Results Antibiotic resistance levels among Escherichia coli and Klebsiella pneumoniae were similar in all Nordic countries in 2018 and low compared to the European mean. Guidelines for acute pyelonephritis varied; 2nd generation cephalosporin (Finland), 3rd generation cephalosporins (Sweden, Norway), ampicillin with an aminoglycoside or aminoglycoside monotherapy (Denmark, Iceland and Norway). Corresponding guidelines for sepsis of unknown origin were 2nd (Finland) or 3rd (Sweden, Norway, Iceland) generation cephalosporins, carbapenems, (Sweden) combinations of penicillin with an aminoglycoside (Norway, Denmark), or piperacillin-tazobactam (all Nordic countries). Methicillin-resistant Staphylococcus aureus rates were 0-2% and empirical treatment with anti-MRSA antibiotics was not recommended in any country. Rates of penicillin non-susceptibility among Streptococcus pneumoniae were low (<10%) except in Finland and Iceland (<15%), but benzylpenicillin was recommended for community-acquired pneumonia in all countries. Conclusion Despite similar resistance rates among Enterobacteriaceae there were differences in practice guidelines for pyelonephritis and sepsis. National surveillance of antibiotic resistance can be used for comparison and optimization of guidelines and stewardship interventions to preserve the low levels of antibiotic resistance in Nordic countries.
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| 7. |
- Rögnvaldsson, Kristjan Godsk, et al.
(författare)
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Obstructive sleep apnea is an independent risk factor for severe COVID-19 : a population-based study
- 2022
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Ingår i: Sleep. - : Oxford University Press (OUP). - 0161-8105 .- 1550-9109. ; 45:3
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Tidskriftsartikel (refereegranskat)abstract
- Study Objectives Obstructive sleep apnea (OSA) has been proposed as a risk factor for severe COVID-19. Confounding is an important consideration as OSA is associated with several known risk factors for severe COVID-19. Our aim was to assess the association of OSA with hospitalization due to COVID-19 using a population-based cohort with detailed information on OSA and comorbidities. Methods Included were all community-dwelling Icelandic citizens 18 years of age and older diagnosed with SARS-CoV-2 infection in 2020. Data on demographics, comorbidities, and outcomes of COVID-19 was obtained from centralized national registries. Diagnosis of OSA was retrieved from the centralized Sleep Department Registry at Landspitali - The National University Hospital. Severe COVID-19 was defined as the composite outcome of hospitalization and death. The associations between OSA and the outcome were expressed as odds ratios (OR) with 95% confidence intervals (95% CI), calculated using logistic regression models and inverse probability weighting. Results A total of 4,756 individuals diagnosed with SARS-CoV-2 infection in Iceland were included in the study (1.3% of the Icelandic population), of whom 185 had a diagnosis of OSA. In total, 238 were hospitalized or died, 38 of whom had OSA. Adjusted for age, sex, and BMI, OSA was associated with poor outcome (OR 2.2, 95% CI 1.4-3.5). This association was slightly attenuated (OR 2.0, 95% CI 2.0, 1.2-3.2) when adjusted for demographic characteristics and various comorbidities. Conclusions OSA was associated with twofold increase in risk of severe COVID-19, and the association was not explained by obesity or other comorbidities.
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| 8. |
- Sallam, Malik, et al.
(författare)
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Decreasing prevalence of transmitted drug resistance among ART-naive HIV-1-infected patients in Iceland, 1996–2012
- 2017
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Ingår i: Infection Ecology and Epidemiology. - : Informa UK Limited. - 2000-8686. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Resistance to antiretroviral drugs can complicate the management of HIV-1 infection and impair control of its spread. The aim of the current study was to investigate the prevalence and transmission of HIV-1 drug resistance among 106 antiretroviral therapy (ART)-naïve patients diagnosed in Iceland (1996–2012).Methods: HIV-1 polymerase sequences were analysed using the Calibrated Population Resistance tool. Domestic spread of transmitted drug resistance (TDR) was investigated through maximum likelihood and Bayesian approaches.Results: Among ART-naïve patients, the prevalence of TDR to any of the following classes (NRTIs, NNRTIs and PIs) was 8.5% (95% CI: 4.5%- 15.4%): 6.6% to NRTIs, 0.9% to NNRTIs, and 1.9% to PIs. The most frequent NRTI mutation detected was T215C/D (n=7, 5.7%). The only NNRTI mutation detected was K103N (n=1, 0.9%). PI mutations detected were M46I (n=1, 0.9%) and L90M (n=1, 0.9%). Six patients harbouring T215C/D, were linked in a supported phylogenetic cluster. No significant association was found between TDR and demographic or risk groups. Trend analysis showed a decrease in the prevalence of TDR (1996–2012, p=0.003).Conclusions: TDR prevalence in Iceland was at a moderate level and decreased during 1996-2012. Screening for TDR is recommended to limit its local spread and to optimize HIV-1 therapy.
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| 9. |
- Sallam, Malik, et al.
(författare)
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Molecular epidemiology of HIV-1 in Iceland : Early introductions, transmission dynamics and recent outbreaks among injection drug users
- 2017
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Ingår i: Infection, Genetics and Evolution. - : Elsevier BV. - 1567-7257 .- 1567-1348. ; 49, s. 157-163
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Tidskriftsartikel (refereegranskat)abstract
- The molecular epidemiology of HIV-1 in Iceland has not been described so far. Detailed analyses of the dynamics of HIV-1 can give insights for prevention of virus spread. The objective of the current study was to characterize the genetic diversity and transmission dynamics of HIV-1 in Iceland. Partial HIV-1 pol (1020bp) sequences were generated from 230 Icelandic samples, representing 77% of all HIV-1 infected individuals reported in the country 1985-2012. Maximum likelihood phylogenies were reconstructed for subtype/CRF assignment and determination of transmission clusters. Timing and demographic growth patterns were determined in BEAST. HIV-1 infection in Iceland was dominated by subtype B (63%, n=145) followed by subtype C (10%, n=23), CRF01_AE (10%, n=22), sub-subtype A1 (7%, n=15) and CRF02_AG (7%, n=15). Trend analysis showed an increase in non-B subtypes/CRFs in Iceland over the study period (p=0.003). The highest proportion of phylogenetic clustering was found among injection drug users (IDUs; 89%), followed by heterosexuals (70%) and men who have sex with men (35%). The time to the most recent common ancestor of the oldest subtype B cluster dated back to 1978 (median estimate, 95% highest posterior density interval: 1974-1981) suggesting an early introduction of HIV-1 into Iceland. A previously reported increase in HIV-1 incidence among IDUs 2009-2011 was revealed to be due to two separate outbreaks. Our study showed that a variety of HIV-1 subtypes and CRFs were prevalent in Iceland between 1985 and 2012, with subtype B being the dominant form both in terms of prevalence and domestic spread. The rapid increase of HIV-1 infections among IDUs following a major economic crisis in Iceland raises questions about casual associations between economic factors, drug use and public health.
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| 10. |
- Sartelli, Massimo, et al.
(författare)
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Ten golden rules for optimal antibiotic use in hospital settings: the WARNING call to action
- 2023
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Ingår i: WORLD JOURNAL OF EMERGENCY SURGERY. - 1749-7922. ; 18:1
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Forskningsöversikt (refereegranskat)abstract
- Antibiotics are recognized widely for their benefits when used appropriately. However, they are often used inappropriately despite the importance of responsible use within good clinical practice. Effective antibiotic treatment is an essential component of universal healthcare, and it is a global responsibility to ensure appropriate use. Currently, pharmaceutical companies have little incentive to develop new antibiotics due to scientific, regulatory, and financial barriers, further emphasizing the importance of appropriate antibiotic use. To address this issue, the Global Alliance for Infections in Surgery established an international multidisciplinary task force of 295 experts from 115 countries with different backgrounds. The task force developed a position statement called WARNING (Worldwide Antimicrobial Resistance National/International Network Group) aimed at raising awareness of antimicrobial resistance and improving antibiotic prescribing practices worldwide. The statement outlined is 10 axioms, or "golden rules," for the appropriate use of antibiotics that all healthcare workers should consistently adhere in clinical practice.
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