MRSA prevalence among healthcare personnel in contact tracings in hospitals. / MRSA-forekomst blant helsepersonell ved smitteoppsporing i sykehus.

BAKGRUNN: I norsk helsevesen gjennomføres omfattende tiltak for å hindre spredning av meticillinresistente Staphylococcus aureus (MRSA). Vi ønsket å undersøke hvor mange smitteoppsporinger som gjøres rundt nyoppdagede MRSA-tilfeller hos pasienter og ansatte i sykehus, og hvor ofte smitteoppsporingene fører til ytterligere funn hos helsepersonell. MATERIALE OG METODE: I denne retrospektive observasjonsstudien bidro smittevernenhetene ved åtte helseforetak i landets fire helseregioner med opplysninger om MRSA-funn hos helsepersonell etter gjennomførte MRSA-smitteoppsporinger. Data ble innhentet fra 14 ulike somatiske sykehus i årene 2012-15. RESULTATER: 10 142 ansatte i helsevesenet ble testet for MRSA, med positivt funn hos 31 ansatte (0,31 %). Hos 19 ansatte (0,19 %) ble det påvist samme MRSA-stamme som hos indekskasus. I kun to av 351 smitteoppsporinger (0,57 %) ble samme MRSA-stamme funnet hos mer enn én ansatt. FORTOLKNING: MRSA-smitteoppsporing i norske sykehus har et betydelig omfang, men det er sjelden det påvises MRSA hos helsepersonell i forbindelse med smitteoppsporing.

A worrying trend in weight-adjusted paediatric antibiotic use in a Norwegian tertiary care hospital.

AIM: The World Health Organization recommends the defined daily dose (DDD) as the standard unit of measurement for antibiotic use, but this is not applicable in children. We aimed to assess paediatric antibiotic use in a Norwegian tertiary care hospital using a novel weight-adjusted method. METHODS: We obtained antibiotic purchase data from the hospital pharmacy and administrative data for all admissions from 2002 to 2009 to the paediatric wards at Oslo University Hospital, Rikshospitalet. Recommended daily doses per 100 kg days (RDDs/kg days) were calculated based on national guidelines for paediatric antibiotic use, length of stay and estimated weight for sex and age using national growth references. RESULTS: Total antibiotic use increased significantly from 51.8 to 65.5 RDDs/100 kg days. We found statistically significant annual increases in the consumption of carbapenems (18.0%), third-generation cephalosporins (6.0%) and imidazole derivatives (6.6%) and a considerable difference between total antibiotic use measured in RDDs/100 kg days and DDDs/100 bed days for neonates. CONCLUSION: Weight-adjusted antibiotic use provided a more meaningful description of the quantities of antibiotics consumed than DDDs/100 bed days, particularly for neonates. Total antibiotic use, use of meropenem, third-generation cephalosporins and imidazole derivatives increased significantly despite low prevalence of antibiotic-resistant pathogens.

Hospital- and patient-related factors associated with differences in hospital antibiotic use: analysis of national surveillance results.

BACKGROUND: Surveillance data of antibiotic use are increasingly being used for benchmarking purposes, but there is a lack of studies dealing with how hospital- and patient-related factors affect antibiotic utilization in hospitals. Our objective was to identify factors that may contribute to differences in antibiotic use. METHODS: Based on pharmacy sales data (2006-2011), use of all antibiotics, all penicillins, and broad-spectrum antibiotics was analysed in 22 Health Enterprises (HEs). Antibiotic utilization was measured in World Health Organisation defined daily doses (DDDs) and hospital-adjusted (ha)DDDs, each related to the number of bed days (BDs) and the number of discharges. For each HE, all clinical specialties were included and the aggregated data at the HE level constituted the basis for the analyses. Fourteen variables potentially associated with the observed antibiotic use - extracted from validated national databases - were examined in 12 multiple linear regression models, with four different measurement units: DDD/100 BDs, DDD/100 discharges, haDDD/100 BDs and haDDD/100 discharges. RESULTS: Six variables were independently associated with antibiotic use, but with a variable pattern depending on the regression model. High levels of nurse staffing, high proportions of short (<2 days) and long (>10 days) hospital stays, infectious diseases being the main ICD-10 diagnostic codes, and surgical diagnosis-related groups were correlated with a high use of all antibiotics. University affiliated HEs had a lower level of antibiotic utilization than other institutions in eight of the 12 models, and carried a high explanatory strength. The use of broad-spectrum antibiotics correlated strongly with short and long hospital stays. There was a residual variance (30%-50% for all antibiotics; 60%-70% for broad-spectrum antibiotics) that our analysis did not explain. CONCLUSIONS: The factors associated with hospital antibiotic use were mostly non-modifiable. By adjusting for these factors, it will be easier to evaluate and understand observed differences in antibiotic use between hospitals. Consequently, the inter-hospital differences can be more confidently acted upon. The residual variation is presumed to largely reflect prescriber-related factors.

Antibiotic resistance in hospitals: a ward-specific random effect model in a low antibiotic consumption environment.

Association between previous antibiotic use and emergence of antibiotic resistance has been reported for several microorganisms. The relationship has been extensively studied, and although the causes of antibiotic resistance are multi-factorial, clear evidence of antibiotic use as a major risk factor exists. Most studies are carried out in countries with high consumption of antibiotics and corresponding high levels of antibiotic resistance, and currently, little is known whether and at what level the associations are detectable in a low antibiotic consumption environment. We conduct an ecological, retrospective study aimed at determining the impact of antibiotic consumption on antibiotic-resistant Pseudomonas aeruginosa in three hospitals in Norway, a country with low levels of antibiotic use. We construct a sophisticated statistical model to capture such low signals. To reduce noise, we conduct our study at hospital ward level. We propose a random effect Poisson or binomial regression model, with a reparametrisation that allows us to reduce the number of parameters. Inference is likelihood based. Through scenario simulation, we study the potential effects of reduced or increased antibiotic use. Results clearly indicate that the effects of consumption on resistance are present under conditions with relatively low use of antibiotic agents. This strengthens the recommendation on prudent use of antibiotics, even when consumption is relatively low.

Reducing post-caesarean surgical wound infection rate: an improvement project in a Norwegian maternity clinic.

BACKGROUND: During 2006 and 2007 the rate of caesarean section surgical wound infection was 17,4 % in Baerum Hospital. OBJECTIVE: The objective was to reduce the incidence to below the Norwegian national level of 8 %. DESIGN: The intervention (a quality improvement project) was implemented in September 2008. A bundle of measures were introduced. Staff from all aspects of patient flow was recruited. Cochrane literature was used as gold standard. Data registration was based upon CDC criteria. RESULTS: were based on data collected through the Norwegian national surveillance system for infections in health care, NOIS. Study setting This Maternity clinic has about 2500 births annually and a caesarean section rate pushing 15 %. PATIENT GROUP: The study was conducted on caesarean section patients registered in NOIS (2008-2010). From September 2009 data were harvested continuously. ASSESSMENT: Data were monitored as cumulative incidence rate and by statistical process control as g chart (number of surgeries between infections including a delayed moving average). Infection control staff reported results to Head of Maternity Clinic monthly. RESULTS: The overall rate of caesarean section surgical wound infections was significantly reduced to 3,1 % (2008-2010 about 1 % in 2010). This result was demonstrated elegantly as a marked shift in process in g-chart. We found the g-chart was efficient, sensitive and simple to handle.

Increased antibiotic use in Norwegian hospitals despite a low antibiotic resistance rate.

OBJECTIVES: Although antibiotic use and resistance are low in Norway, the situation risks changing for the worse. We investigated trends in antibiotic use and assessed them in relation to antibiotic resistance in Norway. METHODS: We drew on hospital pharmacy sales data to record antibiotic use from 2002 to 2007 in eight hospitals serving 36% of the nation's population. Antibiotic use was measured using different indices with defined daily doses (DDDs) as the numerator (WHO ATC/DDD classification). RESULTS: Total antibiotic use increased from 1.02 to 1.30 DDDs/1000 inhabitants/day (DIDs) and from 61.7 to 72.4 DDDs/100 bed-days (BDs) (17.4%); related to the number of discharges, no significant DDD change was shown. Their use in core units (adult intensive care units, recovery/post-operative wards and departments of internal medicine and surgery with all subspecialties) increased from 64.1 to 80.8 DDDs/100 BDs (26.1%) and by 3.1% related to the number of discharges. The total use of broad-spectrum antibiotics increased by 47.9% when measured as DDDs/100 BDs, and by 19.1% based on the number of discharges; the corresponding figures for core units were 60.5% and 31.2%, respectively. CONCLUSIONS: There was a substantial increase in total antibiotic use, and an even more pronounced increase in the use of broad-spectrum antibiotics, which seems unjustified considering the current low antibiotic resistance in Norway.

Local hospital perspective on a nationwide outbreak of Pseudomonas aeruginosa infection in Norway.

OBJECTIVE: To implement a system for monitoring of rare events based on statistical process control charts. DESIGN: Statistical process control plotting by g chart of clinical microbiology laboratory data. SETTING: Primary and secondary care Norwegian hospital with a 9-bed intensive care unit. RESULTS: During the winter of 2001-2002 in Norway, there was a national monoclonal nosocomial outbreak of Pseudomonas aeruginosa infection mainly affecting patients in intensive care units. In the present work, we demonstrate how the use of SPC at one of the affected hospitals would have detected this outbreak several weeks before the alert from the Norwegian National Public Health Institute (NIPH). By plotting the monthly incidence rate of P. aeruginosa infection (with a c chart), we found that the hospital would have been alerted in February; by plotting the number of days between events (with a g chart), we found that the hospital would have detected a process already out of control in early January 2002. Not until 9 weeks later (ie, mid-March) did the NIPH declare the P. aeruginosa outbreak to be national, and a commercially produced mouth swab contaminated during the manufacturing process was found to be the source. CONCLUSION: The plotting of rare events, such as an outbreak of nosocomial infection, with a g chart may be used for early detection of a process out of control.

[An outbreak of methicillin-resistant Staphylococcus aureus infection in a maternity ward]. / Meticillinresistent Staphylococcus aureus-infeksjon i en barselavdeling.

BACKGROUND: Staphylococcus aureus is a frequent cause of serious infections. Methicillin-resistant S. aureus (MRSA) are resistant to almost all types of beta-lactam antibiotics and therefore represent a substantial medical problem. MATERIAL AND METHOD: In April 2006, the Department of Obstetrics at the Asker and Baerum hospital had an outbreak of MRSA that affected four newborns. The source for the infection was sought among family members, other patients and employees, and eradication was attempted. RESULTS: An employee was identified as the probable infectious source. Subsequent investigation identified 13 individuals infected by the same MRSA clone, which was Panton-Valentine-leukocidin (PVL) positive and therefore clearly a pathogen. 10 of the patients had MRSA disease, with 21 months between the first and the last identified case. For 5 of 13 patients MRSA was still detectable after the first attempt of eradication. For 2 patients, including one of the newborns, eradication has so far been unsuccessful and a third patient has acquired a new abscess after one year. INTERPRETATION: Issues connected to MRSA-screening of close contacts and eradication are resource-demanding and require careful consideration of strategy, especially for small children and families with chronic MRSA carriers. Updated detailed national guidelines for MRSA management are needed.

Post-cesarean surgical site infections according to CDC standards: rates and risk factors. A prospective cohort study.

OBJECTIVES: The aim of this study was to document the true incidence of post-cesarean surgical site infections (SSI), according to the definition of the US Centers for Disease Control and Prevention (CDC), and to identify independent risk factors for infection. DESIGN: Prospective population-based cohort study in Norway. Setting. Sykehuset Asker og Baerum HF, a secondary community hospital, associated with the University of Oslo (UiO), Norway, accounting for 2,000 deliveries per year. Participants. All cesarean deliveries during a 12-month period from September 2003. Main outcome measures. Rate and risk factors for SSI. RESULTS: The total rate of SSI was 8.9%, with an observation period of 30 days post-operatively, compared to 1.8% registered at hospital discharge. The total response rate was 100%. There was no significant difference in SSI rate in elective or emergency cesarean section (CS), respectively. All SSI were superficial. We found 2 significant independent risk factors: operating time > or =38 min and body mass index (BMI) >30. CONCLUSION: The rate of SSI is underestimated if the observation time is limited to the hospital stay. Operating time exceeding 38 min substantially increases the risk of SSI. The finding of no significant difference in SSI rate between elective and emergency CS should lead to a different approach concerning the use of antibiotics: subgroup at risk (operating time > or =38 min and BMI >30) may benefit from antibiotics in relation to the operation, whether the CS is an emergency or elective operation.

In vitro activity of a cytotoxic factor isolated from human leukocytes.

The aim of the present study was to test the in vitro antimicrobial properties of a cytotoxic factor isolated from human leukocytes and for an effect on DNA synthesis. A microdilution broth method was used to determine MIC values for fungi and bacteria. Flow cytometry was used to examine the effect on DNA synthesis. The MIC values for fungi were in the range 1-128 microg CF/mL and concentrations 2-4 times the MIC were fungicidal. CF had no effect on bacteria (MIC and MBC values > 1024 microg CF/mL). Growth experiments performed with increasing concentration of CF showed a dose-dependent effect on growth of the yeasts tested. We confirmed that zinc ions could abrogate the antiproliferative effect of CF. Flow cytometric experiments showed that CF had no effect on the cell cyclus. The present study shows that this endogenous substance isolated from human leukocytes has growth inhibitory properties towards fungi. Because of the origin from human leukocytes, CF may have a role in the non-specific defense against fungal infections. The use of CF may potentially have a role in the treatment of infections caused by fungi. Further investigations to characterize CF chemically and to study the antifungal mechanism are necessary.

18S rDNA polymerase chain reaction and sequencing in onychomycosis diagnostics.

Diagnostic approaches to onychomycosis have traditionally been based on a combination of culture and microscopy. In the present study clinical specimens from 346 patients with suspected onychomycosis were analysed by 18S polymerase chain reaction (detection) followed by sequencing and subsequent database search (identification) in parallel with routine culture on agar (detection and identification). In 49 samples Trichophyton rubrum was identified by culture and sequencing. In 67 additional culture negative samples, a positive dermatophyte sequence was obtained (T. rubrum in 54, T. mentagrophytes in 5, and T. species in 8 samples). Fifteen samples cultured positive while no sequence was obtained. Two hundred and seven samples were negative by culture as well as by sequencing. Nails from 10 healthy controls were negative by culture and sequencing. In conclusion, the number of specimens that were positive by polymerase chain reaction was more than double the number that were positive by culture alone.