Risk factors for community-onset bloodstream infection with extended-spectrum ß-lactamase-producing Enterobacteriaceae: national population-based case-control study.

OBJECTIVES: The aim was to investigate risk factors for community-onset bloodstream infections with extended-spectrum ß-lactamase-producing Enterobacteriaceae (EPE BSI). METHODS: It is mandatory to report EPE BSI to a national register at the Public Health Agency of Sweden. Using this register, we performed a population-based case-control study from 2007 to 2012 of 945 cases and 9390 controls. Exposure data on comorbidity, hospitalization, in- and outpatient antibiotic consumption and socio-economic status were collected from hospital and health registers. RESULTS: The overall incidence of EPE BSI was 1.7 per 100 000 person-years. The 30-day mortality was 11.3%. Urological disorders inferred the highest EPE BSI risk, adjusted odds ratio (aOR) 4.32 (95% Confidence Interval (CI) 3.41-5.47), followed by immunological disorders, aOR 3.54 (CI 2.01-6.23), haematological malignancy, aOR 2.77 (CI 1.57-4.87), solid tumours, aOR 2.28 (1.76-2.94) and diabetes, aOR 2.03 (1.58-2.61). Consumption of fluoroquinolones or mostly non-EPE-active antibiotics with selective Gram-negative spectrum of activity within the previous 3 months was associated with EPE BSI, aORs 5.52 (CI 2.8-11.0) and 3.8, CI 1.9-7.7) respectively. There was a dose-response relationship in EPE BSI risk with increasing number of consecutive regimens. Antibiotic consumption >3 months before EPE BSI was not associated with increased risk. Higher age, malignancies and education ≤12 years (aORs >2) were associated with increased 30-day mortality. CONCLUSIONS: Targeted interventions should be directed towards improving care for patients with immunosuppression, urological disorders and subjects with lower socio-economic status. Antibiotic stewardship should focus on reduction of fluoroquinolones.

Increased incidence of invasive group A streptococcal infections in Sweden, January 2012-February 2013.

The incidence of invasive group A streptococcal infections in Sweden was 6.1 per 100,000 population in 2012, the highest since the disease became notifiable in 2004. Furthermore, January and February 2013 marked a dramatic increase of cases notified, partly explainable by an increase of emm1/T1 isolates, a type previously shown to cause severe invasive disease more often than other types. Healthcare providers in Sweden and health authorities in neighbouring countries have been informed about this increase.

Characterization of plasmid-mediated AmpC-producing E. coli from Swedish broilers and association with human clinical isolates.

A selection of plasmid-mediated AmpC-producing Escherichia coli isolates carrying blaCMY-2 from Swedish broilers were characterized to establish their relatedness to and a possible overlap with human clinical E. coli isolates. The results showed diversity among the E. coli isolated from broilers, indicating that the spread in the population was not due to one strain. However, only one type of plasmid belonging to replicon type incK was identified. Furthermore, there were no indications of spread of blaCMY-2 E. coli isolates from broilers to human clinical settings, although Swedish broilers may be a source of blaCMY-2 and/or the plasmid carrying blaCMY-2 .

Geographical clustering of cases of infection with moxifloxacin-resistant Clostridium difficile PCR-ribotypes 012, 017 and 046 in Sweden, 2008 and 2009.

We report the results of two nationwide surveillance studies of Clostridium difficile infection conducted during 2008 and 2009 in Sweden. The first study aimed to identify and quantify the proportion of C. difficile isolates with decreased susceptibility to moxifloxacin, particularly those of PCR-ribotype 027. From December 2007 to September 2008, 20 of 28 regional laboratories sent 585 isolates to the Swedish Institute for Infectious Disease Control for typing. A majority of the isolates (454 of 585; 78%) belonged to four PCR ribotypes (012, SE37, 017 and 046), all clustered in geographical regions. Only two type 027 isolates were found, both from the same patient. In the second study, involving all 28 regional laboratories, all consecutive C. difficile isolates collected during two time periods in 2009 (n=364) were typed and tested for susceptibility to clindamycin, erythromycin, moxifloxacin, metronidazole and vancomycin. The three most common PCR ribotypes were SE21, 001 and 020 (22% of all isolates). Types 012, 017, and 046 were geographically clustered and associated with decreased susceptibility to moxifloxacin, clindamycin and erythromcin. The extent of moxifloxacin prescription was highly variable among counties, indicating a need for careful monitoring of prescription rates to follow its role in C. difficile epidemiology.

Alarming spread of vancomycin resistant enterococci in Sweden since 2007.

The total number of persons infected or colonised with vancomycin-resistant enterococci mandatorily reported to the Swedish Institute for Infectious Disease Control increased dramatically during 2007 and 2008. During a period of twenty months from 1 July 2007 to 28 February 2009, a total of 760 cases were reported compared with 194 cases reported during the entire period from 2000 to 2006. This rise was mainly attributed to a wide dissemination of vancomycin resistant enterococci which started in a number of hospitals in Stockholm in the autumn of 2007 and was followed by dissemination in various healthcare facilities (hospitals and homes for the elderly) in a further two Swedish counties in 2008. The majority of the cases (97%) were acquired in Sweden and among these, healthcare-acquired E. faecium vanB dominated (n=634). The majority of these isolates had identical or closely related pulsed-field gel electrophoresis patterns indicating clonal dissemination in the affected counties. The median minimum inhibitory concentration of vancomycin was 32 mg/L (ranging from 4 to >128 mg/L) and of teichoplanin 0.12 mg/L (ranging from 0.06 to 0.25 mg/L). Particular emphasis was placed on countermeasures such as screening, contact tracing, cleaning procedures, education in accurate use of infection control practices as well as increasing awareness of hygiene among patients and visitors. With these measures the dissemination rate decreased substantially, but new infections with the E. faecium vanB strain were still detected.

Rapid culture and identification: a practical method for early preliminary laboratory diagnosis of sepsis.

This study describes the development of a method for rapid preliminary species identification of bacteria from positive blood culture vials. The method yielded preliminary identification results for 496 (92%) of 541 positive blood cultures within 5 h. The method was capable of identifying the most frequently isolated bacteria (i.e., Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, Streptococcus pneumoniae and Enterococcus spp.) to the species level. The method can be established easily, with a materials cost of 2-5 Euros per sample.