Archive for March 18, 2009

Staphylococcus aureus Bloodstream Infections: Risk Factors, Outcomes, and the Influence of Methicillin Resistance in Calgary, Canada, 2000–2006

Journal of Infectious Diseases 1 August 2008 V.198 N.3 p.336–343

Kevin B. Laupland,1,2,3,4 Terry Ross,3,4 and Daniel B. Gregson1,2,4

Departments of 1Medicine and 2Pathology and Laboratory Medicine, and 3Centre for Anti-microbial Resistance, University of Calgary and Calgary Health Region, and 4Calgary Laboratory Services, Calgary, Alberta, Canada

Background.Reports have suggested that the epidemiological profile of invasive Staphylococcus aureus infections is changing. We sought to describe the epidemiological profile of S. aureus bacteremia and to assess whether the incidence and severity of and the antimicrobial resistance rates associated with this bacteremia are increasing.

Methods.Population-based surveillance for S. aureus bacteremias was conducted in the Calgary Health Region (population, 1.2 million) during 2000–2006.

Results.The annual incidence of S. aureus bacteremia was 19.7 cases/100,000 population. Although rates of health care–associated and nosocomial methicillin-susceptible S. aureus (MSSA) bacteremia were similar throughout the study, rates of community-acquired MSSA bacteremia gradually decreased, and rates of methicillin-resistant S. aureus (MRSA) bacteremia dramatically increased. The clonal type predominantly isolated was CMRSA-2 (i.e., Canadian [C] MRSA-2), but CMRSA-10 (USA300) strains have been increasingly isolated, especially from community-onset infections, since 2004. Dialysis dependence, organ transplantation, HIV infection, cancer, and diabetes were the most important risk factors and were comparable for MSSA and MRSA bacteremias. The overall case-fatality rate was higher among individuals with MRSA (39%) than among those with MSSA (24%; ). The annual overall population mortality rate associated with S. aureus bacteremia did not significantly change during the study.

Conclusions.Although the overall influence of S. aureus bacteremia has not significantly changed, MRSA has emerged as an important etiology in our region


March 18, 2009 at 5:19 pm Leave a comment

Zoonotic Chlamydophila psittaci infections from a clinical perspective

Clinical Microbiology and Infection January 2009 V.15 N.1 p.11-17


D. S. A. Beeckman and D. C. G. Vanrompay

Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium

Corresponding author and reprints requests: D. S. A. Beeckman, Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium


Human psittacosis is a zoonotic infectious disease which is caused by the obligate intracellular bacterium Chlamydophila psittaci. Transmission of the disease usually originates from close contact with infected birds, most frequently in the context of the poultry industry, and from contact with Psittaciformes (cockatoos, parrots, parakeets and lories). Due to a low awareness of the disease and a variable clinical presentation psittacosis is often not recognised as such by general practitioners. This review therefore gives an overview of the epidemiology, symptoms, diagnosis and possible treatments for psittacosis in humans. The current case definition for epidemiological surveillance, as issued by the CDC, is discussed, as well as the possible emergence of Cp. psittaci antibiotic-resistant strains. There is an urgent need for information and for awareness campaigns directed at professional health care workers and the general public. In addition, a broader use of new diagnostic methods in medical laboratories and the development of prophylactics are called for.


March 18, 2009 at 5:18 pm Leave a comment

Effect of antimicrobial therapy on mortality in 377 episodes of Enterobacter spp. Bacteraemia

Journal of Antimicrobial Chemotherapy August 2008 V.62 N.2 p.397-403

Miguel Marcos1,*, Amaia Iñurrieta1, Alex Soriano1, José A. Martínez1, Manel Almela2, Francesc Marco2 and Josep Mensa1

1 Department of Infectious Diseases, Hospital Clinic of Barcelona, C/ Villarroel 170, Barcelona 08036, Spain 2 Department of Microbiology, Hospital Clinic of Barcelona, C/ Villarroel 170, Barcelona 08036, Spain

Objectives: The impact of appropriate antimicrobial therapy and antimicrobial resistance on the outcome of bacteraemia due to Enterobacter spp. remains unclear. The aim of our study was to evaluate the effect of antimicrobial therapy in 377 consecutive episodes of Enterobacter bacteraemia.

Patients and methods: This includes retrospective analysis of a prospectively collected cohort. Clinical variables recorded were age, underlying diseases, use of corticosteroids, prognosis of underlying disease according to the McCabe and Jackson criteria, source of bacteraemia, need for mechanical ventilation, empirical antibiotic treatment, definitive treatment, antimicrobial susceptibility, presentation with septic shock and 30 day mortality rate. Univariate and multivariable analyses were performed to analyse the influence of antibiotic treatment and cephalosporin resistance on mortality.

Results: Between 1991 and 2006, 377 episodes of bacteraemia due to Enterobacter spp. (2.2%) were recorded. The frequency of Enterobacter bacteraemia significantly increased over these years. The overall mortality rate was 12.5% (47 of 377). Independent factors associated with 30 day mortality in patients with monomicrobial bacteraemia were rapidly fatal prognosis when compared with non-fatal prognosis, presentation with septic shock, patient under mechanical ventilation and unknown source of infection. The only factor independently associated with lower 30 day mortality was the empirical use of piperacillin/tazobactam.

Conclusions: Enterobacter spp. are an increasing cause of bacteraemia. The empirical use of piperacillin/tazobactam was independently associated with a lower 30 day mortality rate.


March 18, 2009 at 5:16 pm Leave a comment

Management of hepatitis B virus

Journal of Antimicrobial Chemotherapy August 2008 V.62 N.2 p.224-228

Leading articles

Nidhi A. Singh and Nancy Reau*

Section of Gastroenterology and Hepatology, University of Chicago, Chicago, IL, USA

Hepatitis B is a common problem worldwide with serious sequelae. Despite the explosion of new agents, management has grown even more complicated. The treatment paradigm is evolving from limited therapy to lifelong viral suppression in several populations. This shift has been a direct result of not only well-tolerated oral medications, but also the increasing recognition that active viral replication leads to untoward events such as cirrhosis, liver failure and hepatocellular carcinoma. However, therapy is not without risk, which includes side effects, cost and drug resistance. Controversy surrounds several clinical questions, including which patients are eligible for therapy, which treatment is optimal and at what point may therapy be discontinued. This commentary will discuss these questions as well as the limitations of the literature used to support our current treatment recommendations.


March 18, 2009 at 5:14 pm Leave a comment


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