Outcomes following the implementation of a quality control campaign to decrease sternal wound infections after coronary artery by-pass grafting.

BACKGROUND: Coronary artery by-pass grafting (CABG) remains the optimal strategy in achieving complete revascularization in patients with complex coronary artery disease. However, sternal wound infections (SWI), especially deep SWI are potentially severe complications to the surgery. At the department of cardiothoracic surgery in Uppsala University Hospital a gradual increase in all types of SWI occurred, which peaked in 2009. This prompted an in-depth revision of the whole surgical process. To monitor the frequency of post-operative infections all patients receive a questionnaire that enquires whether any treatment for wound infection has been carried out. METHODS: All patients operated with isolated CABG between start of 2006 and end of 2012 were included in the study. 1515 of 1642 patients answered and returned the questionnaire (92.3 %). The study period is divided into the time before the intervention program was implemented (2006-early 2010) and the time after the intervention (early 2010- end 2012). To assess whether potential differences in frequency of SWI were a consequence of change in the characteristics of the patient population rather than an effect of the intervention a retrospective assessment of medical records was performed, where multiple of the most known risk factors for developing SWI were studied. RESULTS: We noticed a clear decrease in the frequency of SWI after the intervention. This was not a consequence of a healthier population. CONCLUSIONS: Our results from implementing the intervention program are positive in that they reduce the number of SWI. As several changes in the perioperative care were introduced simultaneously we cannot deduce which is the most effective.

Infection prevention and control interventions in the first outbreak of methicillin-resistant Staphylococcus aureus infections in an equine hospital in Sweden.

BACKGROUND: The first outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection in horses in Sweden occurred in 2008 at the University Animal Hospital and highlighted the need for improved infection prevention and control. The present study describes interventions and infection prevention control in an equine hospital setting July 2008 - April 2010. METHOD: This descriptive study of interventions is based on examination of policy documents, medical records, notes from meetings and cost estimates. MRSA cases were identified through clinical sampling and telephone enquiries about horses post-surgery. Prospective sampling in the hospital environment with culture for MRSA and genotyping of isolates by spa-typing and pulsed-field gel electrophoresis (PFGE) were performed. RESULTS: Interventions focused on interruption of indirect contact spread of MRSA between horses via staff and equipment and included: Temporary suspension of elective surgery; and identification and isolation of MRSA-infected horses; collaboration was initiated between authorities in animal and human public health, human medicine infection control and the veterinary hospital; extensive cleaning and disinfection was performed; basic hygiene and cleaning policies, staff training, equipment modification and interior renovation were implemented over seven months.Ten (11%) of 92 surfaces sampled between July 2008 and April 2010 tested positive for MRSA spa-type 011, seven of which were from the first of nine sampling occasions. PFGE typing showed the isolates to be the outbreak strain (9 of 10) or a closely related strain. Two new cases of MRSA infection occurred 14 and 19 months later, but had no proven connections to the outbreak cases. CONCLUSIONS: Collaboration between relevant authorities and the veterinary hospital and formation of an infection control committee with an executive working group were required to move the intervention process forward. Support from hospital management and the dedication of staff were essential for the development and implementation of new, improved routines. Demonstration of the outbreak strain in the environment was useful for interventions such as improvement of cleaning routines and interior design, and increased compliance with basic hygienic precautions. The interventions led to a reduction in MRSA-positive samples and the outbreak was considered curbed as no new cases occurred for over a year.

Mechanical bowel preparation does not affect the intramucosal bacterial colony count.

PURPOSE: The aim of this study was to determine if mechanical bowel preparation (MBP) influences the intramucosal bacterial colony count in the colon. MATERIALS AND METHODS: Macroscopically normal colon mucosa was collected from 37 patients (20 with and 17 without MBP) who were undergoing elective colorectal surgery at three hospitals. The biopsies were processed and cultured in the same laboratory. Colony counts of the common pathogens Escherichia coli and Bacteroides as well as of total bacteria were conducted. The study groups were comparable with regard to age, gender, antibiotics use, diagnosis and type of resection. RESULTS: MBP did not influence the median colony count of E. coli, Bacteroides or total bacteria in our study. CONCLUSIONS: MBP did not affect the intramucosal bacterial count in this study. Further studies are suggested to confirm these findings.

Tracheostomy inner cannula care: a randomized crossover study of two decontamination procedures.

BACKGROUND: Today several methods for decontaminating inner cannulae exist. These methods are not based on scientific data, but often on local clinical tradition. This study compares two different decontamination methods. The aim was to find a practical and safe decontamination method. It is a randomized, single-blinded, comparative crossover study. METHODS: Fifty outpatients with long-term tracheostomy with an inner cannula were consecutively included and randomly allocated to begin with one of two different treatment sequences: detergent and chlorhexidine-alcohol (A) or detergent (B). Samples for bacterial culture were taken before and after decontamination, and the number of bacteria colonies was counted. RESULTS: Before decontamination, the inner cannulae grew high numbers of bacteria, which were parts of the normal flora of the upper respiratory tract and did not differ significantly between the two sequences (AB; BA). The primary variable was the culture count value after chlorhexidine-alcohol/detergent (A) and detergent (B). The effects of both methods were larger than expected, and the results showed a nearly total elimination of organisms. The equivalence criterion, ratio of mean colony counts (A/B) >0.8, was met at a significance level of P<0.001. CONCLUSIONS: Cleaning the tracheostomy inner cannula with detergent and water is sufficient to achieve decontamination.

Evaluation of molecular typing methods in characterizing a European collection of epidemic methicillin-resistant Staphylococcus aureus strains: the HARMONY collection.

We analyzed a representative sample of methicillin-resistant Staphylococcus aureus (MRSA) from 11 European countries (referred to as the HARMONY collection) using three molecular typing methods used within the HARMONY group to examine their usefulness for large, multicenter MRSA surveillance networks that use these different laboratory methodologies. MRSA isolates were collected based on their prevalence in each center and their genetic diversity, assessed by pulsed-field gel electrophoresis (PFGE). PFGE groupings (< or = 3 bands difference between patterns) were compared to those made by sequencing of the variable repeats in the protein A gene spa and clonal designations based on multilocus sequence typing (MLST), combined with PCR analysis of the staphylococcal chromosome cassette containing the mec genes involved in methicillin resistance (SCCmec). A high level of discrimination was achieved using each of the three methodologies, with discriminatory indices between 89.5% and 91.9% with overlapping 95% confidence intervals. There was also a high level of concordance of groupings made using each method. MLST/SCCmec typing distinguished 10 groups containing at least two isolates, and these correspond to the majority of nosocomial MRSA clones described in the literature. PFGE and spa typing resolved 34 and 31 subtypes, respectively, within these 10 MRSA clones, with each subtype differing only slightly from the most common pattern using each method. The HARMONY group has found that the methods used in this study differ in their availability and affordability to European centers involved in MRSA surveillance. Here, we demonstrate that the integration of such technologies is achievable, although common protocols (such as we have developed for PFGE) may also be important, as is the use of centralized Internet sites to facilitate data analysis. PFGE and spa-typing data from analysis of MRSA isolates from the many centers that have access to the relevant equipment can be compared to reference patterns/sequences, and clonal designations can be made. In the majority of cases, these will correspond to those made by the (more expensive) method of choice-MLST/SCCmec typing-and these alternative methods can therefore be used as frontline typing systems for multicenter surveillance of MRSA.

Inflammatory response in patients with malignant obstructive jaundice.

OBJECTIVE: Surgery in patients with malignant obstructive jaundice is associated with increased risks for postoperative septic complications. The aim of this study was to investigate the inflammatory and the local cellular immune response in patients accepted for surgery because of tumours in the hepatic-pancreatic-biliary (HPB) tract. MATERIAL AND METHODS: Patients with obstructive jaundice (group HPB(+)) were compared with those without (HPB(-)). Patients undergoing surgery for benign abdominal disorders served as controls. Obstructive jaundice was present in 18 out of 33 HPB patients. Preoperatively, blood was analysed for bacteria, endotoxins and cytokines (TNF-alpha, IL-6 and IL-10). At operation, mesenteric lymph nodes (MLNs) were excised for bacterial cultures using standard microbiological techniques, and immunohistochemistry, using antibodies CD4 and CD8 (mainly staining T lymphocytes), CD68 (macrophages), and anti-caspase-3 (to determine the rate of apoptosis). RESULTS: Bacterial translocation was not demonstrated in any of the patients. Increased preoperative concentrations of endotoxins were found in group HPB(+). The number of macrophages and the rate of apoptosis in MLNs were increased in jaundiced patients, while the number of T lymphocytes was decreased. CONCLUSIONS: Malignant obstructive jaundice causes increased blood concentrations of endotoxins and cytokines, an increased number of macrophages in MLNs, a higher rate of apoptosis in MLNs, but a decreased number of T lymphocytes in MLNs. The lymphocyte depletion is probably due to the increased rate of apoptosis, and might reduce the ability of jaundiced patients to eradicate infection.

Nasal and hand carriage of Staphylococcus aureus in staff at a Department for Thoracic and Cardiovascular Surgery: endogenous or exogenous source?

OBJECTIVE: To investigate the rates of Staphylococcus aureus carriage on the hands and in the noses of healthcare workers (HCWs) and the relatedness of S. aureus isolates found in the two sites. DESIGN: Point-prevalence study. SETTING: Department for Thoracic and Cardiovascular Surgery at the University Hospital of Uppsala, Uppsala, Sweden. SUBJECTS AND METHODS: Samples were obtained from 133 individuals, 18 men and 115 women, using imprints of each hand on blood agar and a swab from the nose. S. aureus isolates were identified by standard methods and typed by pulsed-field gel electrophoresis. RESULTS: S. aureus was found on the hands of 16.7% of the men and 9.6% of the women, and in the noses of 33.3% of the men and 17.4% of the women. The risk ratio for S. aureus carriage on the hands with nasal carriage was 7.4 (95% confidence interval, 2.7 to 20.2; P < .001). Among the 14 HCWs carrying S. aureus on their hands, strain likeness to the nasal isolate was documented for 7 (50%). CONCLUSIONS: Half of the HCWs acquired S. aureus on the hands from patients or the environment and half did so by apparent self-inoculation from the nose. Regardless of the source of contamination, good compliance with hand hygiene is needed from all HCWs to protect patients from nosocomial infections. The moderate rate of S. aureus carriage on hands in this setting could be the result of the routine use of alcoholic hand antisepsis.

Harmonization of pulsed-field gel electrophoresis protocols for epidemiological typing of strains of methicillin-resistant Staphylococcus aureus: a single approach developed by consensus in 10 European laboratories and its application for tracing the spread of related strains.

Pulsed-fieldgel electrophoresis (PFGE) is the most common genotypic method used in reference and clinical laboratories for typing methicillin-resistant Staphylococcus aureus (MRSA). Many different protocols have been developed in laboratories that have extensive experience with the technique and have established national databases. However, the comparabilities of the different European PFGE protocols for MRSA and of the various national MRSA clones themselves had not been addressed until now. This multinational European Union (EU) project has established for the first time a European database of representative epidemic MRSA (EMRSA) strains and has compared them by using a new "harmonized" PFGE protocol developed by a consensus approach that has demonstrated sufficient reproducibility to allow the successful comparison of pulsed-field gels between laboratories and the tracking of strains around the EU. In-house protocols from 10 laboratories in eight European countries were compared by each center with a "gold standard" or initial harmonized protocol in which many of the parameters had been standardized. The group found that it was not important to standardize some elements of the protocol, such as the type of agarose, DNA block preparation, and plug digestion. Other elements were shown to be critical, namely, a standard gel volume and concentration of agarose, the DNA concentration in the plug, the ionic strength and volume of running buffer used, the running temperature, the voltage, and the switching times of electrophoresis. A new harmonized protocol was agreed on, further modified in a pilot study in two laboratories, and finally tested by all others. Seven laboratories' gels were found to be of sufficiently good quality to allow comparison of the strains by using a computer software program, while two gels could not be analyzed because of inadequate destaining and DNA overloading. Good-quality gels and inclusion of an internal quality control strain are essential before attempting intercenter PFGE comparisons. A number of clonally related strains have been shown to be present in multiple countries throughout Europe. The well-known Iberian clone has been demonstrated in Belgium, Finland, France, Germany, and Spain (and from the wider HARMONY collection in Portugal, Slovenia, and Sweden). Strains from the United Kingdom (EMRSA-15 and -16) have been identified in several othercountries, and other clonally related strains have also been identified. This highlights the need for closer international collaboration to monitor the spread of current epidemic strains as well as the emergence of new ones.

Long-term antibiotic resistance surveillance of gram-negative pathogens suggests that temporal trends can be used as a resistance warning system.

Antibiotic resistance among Gram-negative bacteria and antibiotic consumption were investigated at the Karolinska Hospital, Stockholm, Sweden over a 12-y period. The investigation showed an increase in ciprofloxacin resistance of Escherichia coli from 0% in 1991 to 7% in 1997 and to 11% in 1999. Resistance among Pseudomonas aeruginosa isolates to ciprofloxacin increased from 2.5% in 1991 to 9.0% in 1997 and to 13% in 1999. Resistance levels for norfloxacin showed the same high statistical significance in terms of the temporal trend. A more detailed analysis showed higher resistance against norfloxacin in specific wards. Relationships between antibiotic use and antibiotic susceptibility showed different patterns. The increased ciprofloxacin resistance of E. coli and P. aeruginosa during the study period was paralleled by an increased consumption of quinolones. During the 12-y study period the total use of cephalosporins increased 2.5-fold, while the levels of E. coli resistance to cefuroxime and cefotaxime remained stable. A third pattern was seen with trimethoprim-sulfamethoxazole, namely increasing resistance of E. coli as the use of trimethoprim-sulfamethoxazole declined. The analysis of resistance levels and antibiotic consumption in the present study suggests different mechanisms for the increased resistance. The significant trend of increased resistance to antibiotics over time constitutes an important warning system.

A prospective study of infections in burn patients.

In a 3-year prospective study, all infections presenting in the burns unit of a university hospital were registered in a specially designed database. Two-hundred and thirty adult patients were included. Eighty-three patients had in all 176 infections, giving an infection rate of 48 per 1000 patient days including both nosocomial and community-acquired infections. Thirty-five blood-stream infections (BSI) occurred in 22 patients; most common micro-organisms were coagulase-negative staphylococci and methicillin-sensitive Staphylococcus aureus. The device-specific BSI rate was 6 per 1000 central venous catheter days, which is low compared to other burn units. The pneumonia rate was 41 per 1000 ventilator days. Seventy-two patients had 107 burn wound infections. Antibiotics were given to only 50% of the burn patients, including 96% of the patients with infection and 26% of those without infection. Most frequently used antimicrobials were cloxacillin, penicillin and gentamicin. The antibiotic resistance rates were low, and multi-resistant bacteria or fungi were rare. The database can be used to evaluate the effects of changes in burn treatment, staffing and design of burn units, and antimicrobial resistance development in relation to antibiotic usage.