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- 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. |
- 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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| 4. |
- 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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