Archive for August 29, 2008

Interventions to control MRSA: high time for time-series analysis?

Journal of Antimicrobial Chemotherapy  Sept 2008  V.62  N.3  p.431-433

S. Harbarth1,* and M. H. Samore2,3

1 Infection Control Program, University of Geneva Hospitals and Medical School, CH-1211 Geneva 14, Switzerland 2 VA Salt Lake City Health Care System, Salt Lake City, UT 84148, USA 3 Division of Epidemiology, University of Utah School of Medicine, Salt Lake City, UT 84108, USA

Time-series methods are useful in quasi-experimental study designs in which rates of antibiotic-resistant infections are ascertained before and after an intervention. However, uncertainties remain regarding the use of time-series analysis as an appropriate research methodology for analysing the effect of infection control interventions and antibiotic policies on the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA). In particular, there is still a substantial gap in our understanding of what actually happens to MRSA incidence when a planned intervention is made on use of one or more antibiotic drug classes.

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August 29, 2008 at 10:14 pm Leave a comment

Short- versus long-duration antimicrobial treatment for exacerbations of chronic bronchitis: a meta-analysis

Journal of Antimicrobial Chemotherapy  Sept 2008  V.62  N.3  p.442-450

Systematic review

Matthew E. Falagas1,2,3,*, Sofia G. Avgeri1, Dimitrios K. Matthaiou1, George Dimopoulos1,4 and Ilias I. Siempos1

1 Alfa Institute of Biomedical Sciences (AIBS), Athens, Greece 2 Department of Medicine, Tufts University School of Medicine, Boston, MA, USA 3 Department of Medicine, Henry Dunant Hospital, Athens, Greece 4 Intensive Care Unit, ‘Attikon’ University Hospital, Athens, Greece

Objectives: The aim of this study was to evaluate the comparative effectiveness and safety of short (5 days) and long (7 or 10 days) duration antimicrobial treatment of patients with acute exacerbations of chronic bronchitis (AECB).

Methods: We performed a meta-analysis of randomized controlled trials (RCTs) comparing regimens of the same antibiotic (same dosage and same route of administration) administered for a different time period. We searched PubMed, the Cochrane Central Register of Controlled Trials and reference lists from publications, with no language restrictions.

Results: Of the 1031 reports retrieved initially, seven RCTs, enrolling 3083 patients with AECB, met our inclusion criteria. The antimicrobials studied in these seven RCTs were quinolones, cefixime and clarithromycin. There was no difference between the short- and long-duration therapies with regard to treatment success in intention-to-treat [relative risk (RR) = 0.99, 95% confidence interval (CI) 0.95–1.03], clinically evaluable (RR = 0.99, 95% CI 0.96–1.02) or microbiologically evaluable (RR = 0.98, 95% CI 0.93–1.02) patients. Short-duration treatment, when compared with long, was associated with fewer adverse events (RR = 0.84, 95% CI 0.72–0.97).

Conclusions: Short-duration treatment seems to be as effective as and safer than long-duration antimicrobial treatment of patients with AECB. Additional research is required to clarify the long-term outcomes (namely the exacerbation-free interval after the resolution of an initial episode) of the compared regimens.


August 29, 2008 at 10:11 pm Leave a comment

Emergence and spread of azithromycin-resistant Neisseria gonorrhoeae in Scotland

Journal of Antimicrobial Chemotherapy  Sept 2008  V.62  N.3  p.490-494

Helen M. Palmer1,*, Hugh Young1, Andrew Winter2 and Jayshree Dave1

1 Scottish Bacterial Sexually Transmitted Infections Reference Laboratory (SBSTIRL), Department of Medical Microbiology, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 5SA, UK 2 Sandyford Initiative, 2-6 Sandyford Place, Glasgow G3 7NB, UK

Objectives: The aim of this study was to analyse the trend in azithromycin susceptibility (AzDS) of Neisseria gonorrhoeae in Scotland between April 2004 and December 2007, and to characterize isolates exhibiting decreased AzDS or high-level azithromycin resistance (AzHLR).

Methods: Antibiotic susceptibility testing and N. gonorrhoeae multiantigen sequence typing (NG-MAST) were performed on all gonococcal isolates received by the Scottish Bacterial Sexually Transmitted Infections Reference Laboratory (SBSTIRL) during the study period.

Results: AzHLR isolates were observed for the first time in 2004 and increased from 0.3% to 3.9% in 2007. AzDS declined from 2.1% to 1.3% in the same period. Taken together, AzDS and AzHLR isolates accounted for 5.2% of the gonococcal infections in Scotland in 2007. NG-MAST revealed that only a small number of sequence types (STs) contained AzHLR and AzDS isolates; these STs also included azithromycin-susceptible isolates. Most STs containing AzHLR isolates were genetically related on the basis of their por and tbpB alleles; however, demographic data suggested that they formed discrete sexual networks.

Conclusions: AzHLR strains of N. gonorrhoeae are increasing in Scotland. A 1 g dose of azithromycin should not be considered as an alternative antibiotic therapy for gonococcal infections. The use of azithromycin to treat chlamydia in patients co-infected with N. gonorrhoeae results in a level of azithromycin in vivo that is sublethal for N. gonorrhoeae, which may lead to resistance.


August 29, 2008 at 10:09 pm Leave a comment

Pneumonia in HIV-infected Persons

American Journal of Respiratory and Critical Care Medicine  15 Sept 2008  V.178  N.6  p.630-636

Original Article

Increased Risk with Cigarette Smoking and Treatment Interruption

Fred M. Gordin1, Mollie P. Roediger2, Pierre-Marie Girard3, Jens D. Lundgren4, Jose M. Miro5, Adrian Palfreeman6, Maria C. Rodriguez-Barradas7, Marcelo J. Wolff8, Philippa J. Easterbrook9, Kate Clezy10 and Leonard N. Slater11

1 Veterans Affairs Medical Center and George Washington University, Washington, DC; 2 Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, Minnesota; 3 Service des Maladies Infectieuses et Tropicales–Hôpital Saint-Antoine, Université Pierre et Marie Curie, and Institut Médecine et d’Epidémiologie Appliquée, Paris, France; 4 Copenhagen HIV Programme, University of Copenhagen, Copenhagen, Denmark; 5 Hospital Clinic–Institut d’Investigacions Biomèdiques August Pi-Sunyer, University of Barcelona, Barcelona, Spain; 6 University Hospitals of Leicester, Leicester, and Medical Research Council, London, United Kingdom; 7 Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas; 8 University of Chile School of Medicine and Arriaran Foundation, Santiago, Chile; 9 Department of HIV and Genitourinary Medicine, Kings College, London, United Kingdom; 10 University of New South Wales, Sydney, Australia; 11 University of Oklahoma College of Medicine and Veterans Affairs Medical Center, Oklahoma City, Oklahoma

Rationale: Bacterial pneumonia is a major cause of morbidity for HIV-infected persons and contributes to excess mortality in this population.

Objectives: To evaluate the frequency and risk factors for occurrence of bacterial pneumonia in the present era of potent antiretroviral therapy.

Methods: We evaluated data from a randomized trial of episodic antiretroviral therapy. The study, Strategies for Management of Antiretroviral Therapy, enrolled 5,472 participants at 318 sites in 33 countries. Study patients had more than 350 CD4 cells at baseline. Diagnosis of bacterial pneumonia was confirmed by a blinded clinical-events committee.

Measurements and Main Results: During a mean follow-up of 16 months, 116 participants (2.2%) developed at least one episode of bacterial pneumonia. Patients randomized to receive episodic antiretroviral therapy were significantly more likely to develop pneumonia than patients randomized to receive continuous antiretroviral therapy (hazard ratio, 1.55; 95% confidence interval, 1.07–2.25; P = 0.02). Cigarette smoking was a major risk factor: Current-smokers had more than an 80% higher risk of pneumonia compared with never-smokers (hazard ratio, 1.82; 95% confidence interval, 1.09–3.04; P = 0.02). Participants who were on continuous HIV treatment and were current smokers were three times more likely to develop bacterial pneumonia than nonsmokers. Current smoking status was significant, but a past history of smoking was not.

Conclusions: Bacterial pneumonia is a major source of morbidity, even for persons on potent antiretroviral therapy, including those with high CD4 cells. Efforts to reduce this illness should stress the importance of uninterrupted antiretroviral therapy and attainment and/or maintenance of nonsmoking status.


August 29, 2008 at 6:12 pm Leave a comment


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