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Purpose To describe the occurrence of SARS-CoV-2 infections, deaths and outbreaks among residents in Danish long-term care facilities (LTCFs) from February 2020 to February 2021. Methods Danish COVID-19 national register data from a newly implemented automated surveillance system was used to describe incidence rate and deaths (per 1000 residents’ years), number of tests, SARS-CoV-2 infections and outbreaks among LTCF residents. A case was defined as a LTCF resident with a positive SARS-CoV-2 PCR test. An outbreak was defined as two or more cases in one LTCF within a 14-day period, and considered closed if no new cases had occurred within 28 days. Death was defined as occurring within 30-days of a positive test. Results A total of 55,359 residents living in 948 LTCFs were included. The median age of the residents was 85 years and 63% were female. There was a total of 3712 cases found among residents across 43% of all LTCFs. Nearly all (94%) cases were linked to outbreaks. Higher numbers of cases and outbreaks were seen in Denmark’s Capital Region compared to other regions. Overall, 22 SARS-CoV-2 deaths and 359 deaths (non-SARS-CoV-2) per 1000 resident years were identified in the study period. Conclusion Less than half of LTCFs identified any cases. The majority of cases were linked to outbreaks, emphasizing the importance of preventing introductions of SARS-CoV-2 into the facilities. Furthermore, it highlights the need to invest efforts into infrastructures, routine procedures and monitoring of SARS-CoV-2 in LTCFs to limit the introduction and the spread of SARS-CoV-2.

BACKGROUND: We aimed to test the accuracy of an electronic hand hygiene monitoring system (EHHMS) during daily clinical activities in different wards and with varying health care professions.METHODS: The accuracy of an EHHMS (Sani Nudge) was assessed during real clinical conditions by comparing events registered by two observers in parallel with events registered by the EHHMS. The events were categorized as true-positive, false-positive, and false-negative registrations. Sensitivity and positive predictive value (PPV) were calculated.RESULTS: A total of 103 events performed by 25 health care workers (9 doctors, 11 nurses, and 5 cleaning assistants) were included in the analyses. The EHHMS had a sensitivity of 100% and a PPV of 100% when measuring alcohol-based hand rub. When looking at the hand hygiene opportunities of all health care workers combined taking place in the patient rooms and working rooms, the sensitivity was 75% and the PPV 95%. For doctors' and nurses' taking care of patients in their beds the EHHMS had a sensitivity of 100% and a PPV of 94%.CONCLUSIONS: The objective accuracy measures demonstrate that this EHHMS can capture hand hygiene behavior under clinical conditions in different settings with clinical health care workers but show less accuracy with cleaning assistants.

From October 2022 through January 2023, nine patients with NDM-5/OXA-48-carbapenemase-producing Enterobacter hormaechei ST79 were detected in Denmark and subsequently one patient in Iceland. There were no nosocomial links between patients, but they had all been treated with dicloxacillin capsules. An NDM-5/OXA-48-carbapenemase-producing E. hormaechei ST79, identical to patient isolates, was cultured from the surface of dicloxacillin capsules in Denmark, strongly implicating them as the source of the outbreak. Special attention is required to detect the outbreak strain in the microbiology laboratory. From October 2022 through January 2023, nine patients with NDM-5/OXA-48-carbapenemase-producing Enterobacter hormaechei ST79 were detected in Denmark and subsequently one patient in Iceland. There were no nosocomial links between patients, but they had all been treated with dicloxacillin capsules. An NDM-5/OXA-48-carbapenemase-producing E. hormaechei ST79, identical to patient isolates, was cultured from the surface of dicloxacillin capsules in Denmark, strongly implicating them as the source of the outbreak. Special attention is required to detect the outbreak strain in the microbiology laboratory.

Objectives: Population-based estimates of excess length of stay after hospital-acquired bacteraemia (HAB) are few and prone to time-dependent bias. We investigated the excess length of stay and readmission after HAB. Methods: This population-based cohort study included the North Denmark Region adult population hospitalized for ≥48 hours, from 2006 to 2018. Using a multi-state model with 45 days of follow-up, we estimated adjusted hazard ratios (aHRs) for end of stay and discharge alive. The excess length of stay was defined as the difference in residual length of stay between infected and uninfected patients, estimated using a non-parametric approach with HAB as time-dependent exposure. Confounder effects were estimated using pseudo-value regression. Readmission after HAB was investigated using the Cox regression. Results: We identified 3457 episodes of HAB in 484 291 admissions in 205 962 unique patients. Following HAB, excess length of stay was 6.6 days (95% CI, 6.2–7.1 days) compared with patients at risk. HAB was associated with decreased probability of end of hospital stay (aHR, 0.60; 95% CI, 0.57–0.62) driven by the decreased hazard for discharge alive; the aHRs ranged from 0.30 (95% CI, 0.23–0.40) for bacteraemia stemming from ‘heart and vascular’ source to 0.72 (95% CI, 0.69–0.82) for the ‘urinary tract’. Despite increased post-discharge mortality (aHR, 2.76; 95% CI, 2.38–3.21), HAB was associated with readmission (aHR, 1.42; 95% CI, 1.31–1.53). Conclusion: HAB was associated with considerably excess length of hospital stay compared with hospitalized patients without bacteraemia. Among patients discharged alive, HAB was associated with increased readmission rates.

BACKGROUND: Knowledge on hospital-related interventions as risk factors for hospital-acquired bacteraemia (HAB) is sparse.AIM: We aimed to investigate hospital interventions as risk factors for HAB.METHODS: Prospectively through one year, we identified episodes of HAB in a single tertiary hospital. We used a matched incidence density sampled case-control design. Matching on sex and age group, we sampled controls (1:2) from the adult hospital population with ongoing hospitalization for ≥48 h. Using conditional logistic regression, we estimated odds ratios (OR) with 95% confidence intervals (CI). For adjusted ORs (aOR), adjustments were made for length of hospital stay, type and urgency of admission, and Charlson Comorbidity Index score level.FINDINGS: From 15th October 2019 through 14th October 2020, we identified 115 incident episodes of HAB and matched them with 230 controls. HAB patients were more often admitted as 'medicine or emergency surgery'-patients (94% vs 87%) and had a longer hospital stay before inclusion (median days 20 vs 12). They were more frequently categorized as having a 'low level comorbidity' (58% vs 39%) but had higher prevalence of haematologic (15% vs 6%) or metastatic cancer (13% vs 10%). Our estimates for central venous catheters were aOR of 3.46 (95% CI 1.92-6.23), haemodialysis; aOR 5.05 (95% CI 1.41-18.06), immunosuppressive treatment including chemotherapy; aOR of 1.72 (95% CI 1.00-2.96).CONCLUSION: Central venous catheters and haemodialysis were the most prominent risk factors. Immunosuppressive treatment including therapy may play an important role in the development of HAB.

Denmark hosted four games during the 2020 UEFA European championships (EC2020). After declining positive SARS-CoV-2 test rates in Denmark, a rise occurred during and after the tournament, concomitant with the replacement of the dominant Alpha lineage (B.1.1.7) by the Delta lineage (B.1.617.2), increasing vaccination rates and cessation of several restrictions. A cohort study including 33 227 cases was conducted from 30 May to 25 July 2021, 14 days before and after the EC2020. Included was a nested cohort with event information from big-screen events and matches at the Danish national stadium, Parken (DNSP) in Copenhagen, held from 12 June to 28 June 2021. Information from whole-genome sequencing, contact tracing and Danish registries was collected. Case–case connections were used to establish transmission trees. Cases infected on match days were compared to cases not infected on match days as a reference. The crude incidence rate ratio (IRR) of transmissions was 1.55, corresponding to 584 (1.76%) cases attributable to EC2020 celebrations. The IRR adjusted for covariates was lower (IRR 1.41) but still significant, and also pointed to a reduced number of transmissions from fully vaccinated cases (IRR 0.59). These data support the hypothesis that the EC2020 celebrations contributed to the rise of cases in Denmark in the early summer of 2021.

In June–November 2020, SARS-CoV-2-infected mink were detected in 290 of 1,147 Danish mink farms. In North Denmark Region, 30% (324/1,092) of people found connected to mink farms tested SARS-CoV-2-PCR-positive and approximately 27% (95% confidence interval (CI): 25–30) of SARS-CoV-2-strains from humans in the community were mink-associated. Measures proved insufficient to mitigate spread. On 4 November, the government ordered culling of all Danish mink. Farmed mink constitute a potential virus reservoir challenging pandemic control.

PRAISE network: Maaike S. M. van Mourik, Stephanie M.van Rooden, Mohamed Abbas, Olov Aspevall, Pascal Astagneau, Marc J. M. Bonten, Elena Carrara, Aina Gomila-Grange, Sabine C. de Greeff , Sophie Gubbels, Wendy Harrison, Hilary Humphreys, Anders Johansson, Mayke B. G. Koek, Brian Kristensen, Alain Lepape, Jean-Christophe Lucet, Siddharth Mookerjee, Pontus Naucler, Zaira R. Palacios-Baena, Elisabeth Presterl, Miquel Pujol, Jacqui Reilly, Christopher Roberts, Evelina Tacconelli, Daniel Teixeira, Thomas Tängdén, John Karlsson Valik, Michael Behnke, PetraGastmeier., [Introduction] Healthcare-associated infections (HAI) are a major public health concern. Monitoring of HAI rates, with feedback, is a core component of infection prevention and control programmes. Digitalization of healthcare data has created novel opportunities for automating the HAI surveillance process to varying degrees. However, methods are not standardized and vary widely between different healthcare facilities. Most current automated surveillance (AS) systems have been confined to local settings, and practical guidance on how to implement large-scale AS is needed., [Methods] This document was written by a task force formed in March 2019 within the PRAISE network (Providing a Roadmap for Automated Infection Surveillance in Europe), gathering experts in HAI surveillance from ten European countries., [Results] The document provides an overview of the key e-health aspects of implementing an AS system of HAI in a clinical environment to support both the infection prevention and control team and information technology (IT) departments. The focus is on understanding the basic principles of storage and structure of healthcare data, as well as the general organization of IT infrastructure in surveillance networks and participating healthcare facilities. The fundamentals of data standardization, interoperability and algorithms in relation to HAI surveillance are covered. Finally, technical aspects and practical examples of accessing, storing and sharing healthcare data within a HAI surveillance network, as well as maintenance and quality control of such a system, are discussed., [Conclusions] With the guidance given in this document, along with the PRAISE roadmap and governance documents, readers will find comprehensive support to implement large-scale AS in a surveillance network., This network has been supported under the 7th transnational call within the Joint Programming Initiative on Antimicrobial Resistance (JPIAMR), Network Call on Surveillance (2018) and was thereby funded by ZonMw (grant 549007001). This project also received support from the COMBACTE MAGNET EPI-Net project funded by the Innovative Medicines Initiative Joint Undertaking under grant agreement 115523 | 115620 | 115737 | 777362, resources of which are composed of financial contribution from the European Union Seventh Framework Programme (FP7/2007-2013) and EFPIA companies in kind contribution. J.K.V. was supported by grants from Region Stockholm and Vinnova.

Background Carbapenemase-producing Escherichia coli are increasing worldwide. In recent years, an increase in OXA-244-producing E. coli isolates has been seen in the national surveillance of carbapenemase-producing organisms in Denmark. Aim Molecular characterisation and epidemiological investigation of OXA-244-producing E. coli isolates from January 2016 to August 2019. Methods For the epidemiological investigation, data from the Danish National Patient Registry and the Danish register of civil registration were used together with data from phone interviews with patients. Isolates were characterised by analysing whole genome sequences for resistance genes, MLST and core genome MLST (cgMLST). Results In total, 24 OXA-244-producing E. coli isolates were obtained from 23 patients. Among the 23 patients, 13 reported travelling before detection of the E. coli isolates, with seven having visited countries in Northern Africa. Fifteen isolates also carried an extended-spectrum beta-lactamase gene and one had a plasmid-encoded AmpC gene. The most common detected sequence type (ST) was ST38, followed by ST69, ST167, ST10, ST361 and ST3268. Three clonal clusters were detected by cgMLST, but none of these clusters seemed to reflect nosocomial transmission in Denmark. Conclusion Import of OXA-244 E. coli isolates from travelling abroad seems likely for the majority of cases. Community sources were also possible, as many of the patients had no history of hospitalisation and many of the E. coli isolates belonged to STs that are present in the community. It was not possible to point at a single country or a community source as risk factor for acquiring OXA-244-producing E. coli.

Background Carbapenemase-producing Escherichia coli are increasing worldwide. In recent years, an increase in OXA-244-producing E. coli isolates has been seen in the national surveillance of carbapenemase-producing organisms in Denmark. Aim Molecular characterisation and epidemiological investigation of OXA-244-producing E. coli isolates from January 2016 to August 2019. Methods For the epidemiological investigation, data from the Danish National Patient Registry and the Danish register of civil registration were used together with data from phone interviews with patients. Isolates were characterised by analysing whole genome sequences for resistance genes, MLST and core genome MLST (cgMLST). Results In total, 24 OXA-244-producing E. coli isolates were obtained from 23 patients. Among the 23 patients, 13 reported travelling before detection of the E. coli isolates, with seven having visited countries in Northern Africa. Fifteen isolates also carried an extended-spectrum beta-lactamase gene and one had a plasmid-encoded AmpC gene. The most common detected sequence type (ST) was ST38, followed by ST69, ST167, ST10, ST361 and ST3268. Three clonal clusters were detected by cgMLST, but none of these clusters seemed to reflect nosocomial transmission in Denmark. Conclusion Import of OXA-244 E. coli isolates from travelling abroad seems likely for the majority of cases. Community sources were also possible, as many of the patients had no history of hospitalisation and many of the E. coli isolates belonged to STs that are present in the community. It was not possible to point at a single country or a community source as risk factor for acquiring OXA-244-producing E. coli.

BACKGROUND: Hand hygiene compliance (HHC) among health care workers remains suboptimal, and good monitoring systems are lacking. We aimed to evaluate HHC using an automated monitoring system.METHODS: A prospective, observational study was conducted at 2 Danish university hospitals employing a new monitoring system (Sani nudge). Sensors were located on alcohol-based sanitizers, health care worker name tags, and patient beds measuring hand hygiene opportunities and sanitations.RESULTS: In total, 42 nurses were included with an average HHC of 52% and 36% in hospitals A and B, respectively. HHC was lowest in patient rooms (hospital A: 45%; hospital B: 29%) and highest in staff toilets (hospital A: 72%; hospital B: 91%). Nurses sanitized after patient contact more often than before, and sanitizers located closest to room exits and in hallways were used most frequently. There was no association found between HHC level and the number of beds in patient rooms. The HHC level of each nurse was consistent over time, and showed a positive correlation between the number of sanitations and HHC levels (hospital A: r = 0.69; hospital B: r = 0.58).CONCLUSIONS: The Sani nudge system can be used to monitor HHC at individual and group levels, which increases the understanding of compliance behavior.

SUMMARYThe surveillance of Clostridium difficile (CD) in Denmark consists of laboratory based data from Departments of Clinical Microbiology (DCMs) sent to the National Registry of Enteric Pathogens (NREP). We validated a new surveillance system for CD based on the Danish Microbiology Database (MiBa). MiBa automatically collects microbiological test results from all Danish DCMs. We built an algorithm to identify positive test results for CD recorded in MiBa. A CD case was defined as a person with a positive culture for CD or PCR detection of toxin A and/or B and/or binary toxin. We compared CD cases identified through the MiBa-based surveillance with those reported to NREP and locally in five DCMs representing different Danish regions. During 2010–2014, NREP reported 13 896 CD cases, and the MiBa-based surveillance 21 252 CD cases. There was a 99·9% concordance between the local datasets and the MiBa-based surveillance. Surveillance based on MiBa was superior to the current surveillance system, and the findings show that the number of CD cases in Denmark hitherto has been under-reported. There were only minor differences between local data and the MiBa-based surveillance, showing the completeness and validity of CD data in MiBa. This nationwide electronic system can greatly strengthen surveillance and research in various applications.

BACKGROUNDIn 2015, Denmark launched an automated surveillance system for hospital-acquired infections, the Hospital-Acquired Infections Database (HAIBA).OBJECTIVETo describe the algorithm used in HAIBA, to determine its concordance with point prevalence surveys (PPSs), and to present trends for hospital-acquired bacteremiaSETTINGPrivate and public hospitals in DenmarkMETHODSA hospital-acquired bacteremia case was defined as at least 1 positive blood culture with at least 1 pathogen (bacterium or fungus) taken between 48 hours after admission and 48 hours after discharge, using the Danish Microbiology Database and the Danish National Patient Registry. PPSs performed in 2012 and 2013 were used for comparison.RESULTSNational trends showed an increase in HA bacteremia cases between 2010 and 2014. Incidence was higher for men than women (9.6 vs 5.4 per 10,000 risk days) and was highest for those aged 61–80 years (9.5 per 10,000 risk days). The median daily prevalence was 3.1% (range, 2.1%–4.7%). Regional incidence varied from 6.1 to 8.1 per 10,000 risk days. The microorganisms identified were typical for HA bacteremia. Comparison of HAIBA with PPS showed a sensitivity of 36% and a specificity of 99%. HAIBA was less sensitive for patients in hematology departments and intensive care units. Excluding these departments improved the sensitivity of HAIBA to 44%.CONCLUSIONSAlthough the estimated sensitivity of HAIBA compared with PPS is low, a PPS is not a gold standard. Given the many advantages of automated surveillance, HAIBA allows monitoring of HA bacteremia across the healthcare system, supports prioritizing preventive measures, and holds promise for evaluating interventions.Infect Control Hosp Epidemiol 2017;38:559–566

Summary Background In 2011–12, the European Centre for Disease Prevention and Control (ECDC) held the first Europe-wide point-prevalence survey of health-care-associated infections in acute care hospitals. We analysed paediatric data from this survey, aiming to calculate the prevalence and type of health-care-associated infections in children and adolescents in Europe and to determine risk factors for infection in this population. Methods Point-prevalence surveys took place from May, 2011, to November, 2012, in 1149 hospitals in EU Member States, Iceland, Norway, and Croatia. Patients present on the ward at 0800 h on the day of the survey and who were not discharged at the time of the survey were included. Data were collected by locally trained health-care workers according to patient-based or unit-based protocols. We extracted data from the ECDC database for all paediatric patients (age 0–18 years). We report adjusted prevalence for health-care-associated infections by clustering at the hospital and country level. We also calculated risk factors for development of health-care-associated infections with use of a generalised linear mixed-effects model. Findings We analysed data for 17 273 children and adolescents from 29 countries. 770 health-care-associated infections were reported in 726 children and adolescents, corresponding to a prevalence of 4·2% (95% CI 3·7–4·8). Bloodstream infections were the most common type of infection (343 [45%] infections), followed by lower respiratory tract infections (171 [22%]), gastrointestinal infections (64 [8%]), eye, ear, nose, and throat infections (55 [7%]), urinary tract infections (37 [5%]), and surgical-site infections (34 [4%]). The prevalence of infections was highest in paediatric intensive care units (15·5%, 95% CI 11·6–20·3) and neonatal intensive care units (10·7%, 9·0–12·7). Independent risk factors for infection were age younger than 12 months, fatal disease (via ultimately and rapidly fatal McCabe scores), prolonged length of stay, and the use of invasive medical devices. 392 microorganisms were reported for 342 health-care-associated infections, with Enterobacteriaceae being the most frequently found (113 [15%]). Interpretation Infection prevention and control strategies in children should focus on prevention of bloodstream infections, particularly among neonates and infants. Funding None.

BACKGROUND: The Danish Hospital-Acquired Infections Database (HAIBA) is an automated surveillance system using hospital administrative, microbiological, and antibiotic medication data.AIM: To define and evaluate the case definition for hospital-acquired urinary tract infection (HA-UTI) and to describe surveillance data from 2010 to 2014.METHODS: The HA-UTI algorithm defined a laboratory-diagnosed UTI as a urine culture positive for no more than two micro-organisms with at least one at ≥10(4)cfu/mL, and a probable UTI as a negative urine culture and a relevant diagnosis code or antibiotic treatment. UTI was considered hospital-acquired if a urine sample was collected ≥48h after admission and FINDINGS: HAIBA detected a national incidence rate of 42.2 laboratory-diagnosed HA-UTI per 10,000 risk-days with an increasing trend. Compared to PPS the laboratory-diagnosed HA-UTI algorithm had a sensitivity of 50.0% (26/52) and a specificity of 94.2% (1842/1955). There were several reasons for discrepancies between HAIBA and PPS, including laboratory results being unavailable at the time of the survey, the results considered clinically irrelevant by the surveyor due to an indwelling urinary catheter or lack of clinical signs of infection, and UTIs being considered HA-UTI in PPS even though the first sample was taken within 48h of admission.CONCLUSION: The HAIBA algorithm was found to give valid and valuable information and has, among others, the advantages of covering the whole population and allowing continuous standardized monitoring of HA-UTI.

Clin Microbiol Infect ABSTRACT: With the emergence of reduced susceptibility of Clostridium difficile to metronidazole and vancomycin the value of antimicrobial susceptibility testing has increased. The aim of our study was to evaluate disk diffusion for susceptibility testing of C. difficile by comparing disk diffusion results with MICs from gradient tests and to propose zone diameter breakpoint correlates for the EUCAST epidemiological cut-off values (ECOFFs) recently published. We tested 211 clinical isolates of C. difficile, from patients with diarrhoea hospitalized at Aarhus and Odense University Hospitals, Denmark. Furthermore, ten clinical isolates of C. difficile from the Anaerobe Reference Laboratory, University Hospital of Wales, with known reduced susceptibility to either metronidazole or vancomycin, were included. Isolates were tested with Etest gradient strips and disk diffusion towards metronidazole, vancomycin and moxifloxacin on Brucella Blood Agar supplemented with hemin and vitamin K. We found an excellent agreement between inhibition zone diameter and MICs. For each MIC value, the inhibition zones varied from 0 to 8 mm, with 93% of values within 6 mm for metronidazole, 95% of values within 4 mm for vancomycin, and 98% of values within 4 mm for moxifloxacin. With proposed zone diameter breakpoints for metronidazole, vancomycin and moxifloxacin of WT ≥ 23 mm, WT ≥ 19 and WT ≥ 20 mm, respectively, we found no very major errors and only major errors below 2%. In conclusion, we suggest that disk diffusion is an option for antimicrobial susceptibility testing of C. difficile.

Udgivelsesdato: 2009-Mar Abstract We hypothesized that patients coinfected with zoonotic Salmonella and Campylobacter were frailer than monoinfected Salmonella or Campylobacter patients. The study cohort included all first-time Salmonella/Campylobacter infections in Aarhus and North Jutland counties, Denmark, from 1991 through 2003. Data on comorbidity, hospitalization in relation to the Salmonella/Campylobacter infection, and 1-year mortality were obtained from electronic registries. Among 13,449 individuals, 114 (0.85%) had Salmonella/Campylobacter coinfection, 6567 (48.8%) had Salmonella monoinfection, and 6768 (50.3%) had Campylobacter monoinfection. There were no major differences in age, gender, comorbidity, hospitalization rates, 1-year mortality, or seasonal variation between coinfected patients on the one hand and each of the monoinfected patient groups on the other. The main difference was encountered between the Salmonella serotype distribution as 49.1% of coinfected patients versus 20.3% of monoinfected Salmonella patients had Salmonella serotypes other than Salmonella Enteritidis and Salmonella Typhimurium (odds ratio [95% confidence interval]: 4.07 [2.73-6.06]). In conclusion, Salmonella/Campylobacter coinfected patients were not frailer than monoinfected patients. The difference in Salmonella serotype distribution was compatible with a higher proportion of coinfections acquired during foreign travel.

Objective.To investigate the rate of adherence by hospital staff members to the correct use of alcohol-based hand rub before and after performance of clinical procedures.Design.A cohort study conducted during the period from 2006 through 2007 and 2 cross-sectional studies conducted in 2006 and 2007.Setting.Århus University Hospital, Skejby, in Århus, Denmark.Participants.Various hospital staff members.Methods.Following an ongoing campaign promoting the correct use of alcohol-based hand rub, we observed rates of adherence by hospital staff to the correct use of alcohol-based hand rub. Observations were made before and after each contact with patients or patient surroundings during 5 weekdays during the period from 2006 through 2007 in 10 different hospital units. A logistic regression model was used to estimate the rate of adherence to the correct use of alcohol-based hand rub before and after performance of a clinical procedure.Results.A total of 496 participants were observed during 22,906 opportunities for hand hygiene (ie, 11,177 before and 11,729 after clinical procedures) that required the use of alcohol-based hand rub. The overall rates of adherence to the correct use of alcohol-based hand rub were 62.3% (6,968 ofthe 11,177 opportunities) before performance and 68.6% (8,041 ofthe 11,729 opportunities) after performance of clinical procedures. Compared with male participants, female participants were significantly better at adhering to the correct use of alcohol-based hand rub before performance (odds ratio [OR] 1.51 [95% confidence interval {CI}, 1.09–2.10]) and after performance (OR, 1.73 [95% CI, 1.27–2.36]) of clinical procedures. In general, the rate of adherence was significantly higher after the performance of clinical procedures, compared with before (OR, 1.43 [95% CI, 1.35–1.52]). For our cohort of 214 participants who were observed during 14,319 opportunities, the rates of adherence to the correct use of alcohol-based hand rub were 63.2% (4,469 of the 7,071 opportunities) before performance and 69.3% (5,021 of the 7,248 opportunities) after performance of clinical procedures, and these rates increased significantly from 2006 to 2007, except for physicians.Conclusion.We found a high and increasing rate of adherence to the correct use of alcohol-based hand rub before and after performance of clinical procedures following a campaign that promoted the correct use of alcohol-based hand rub. More hospital staff performed hand hygiene with alcohol-based hand rub after performance of clinical procedures, compared with before performance. Future campaigns to improve the rate of adherence to the correct use of alcohol-based hand rub ought be aware that certain groups of hospital staff (eg, male staff members) are known to exhibit a low level of adherence to the correct use of alcohol-based hand rub.

SUMMARYWe report an outbreak with Salmonella Typhimurium DT104 resistant to six different antibiotic classes. The outbreak occurred in Denmark in July/August 2005 and was traced to a single restaurant. In addition to patient interviews, an important tool in the investigation of this outbreak was comparison by multi-locus variable number of tandem repeat analysis (MLVA) typing of patient strains with strains from the food surveillance system. This showed that the source of the outbreak was imported beef served as carpaccio. Carpaccio, thinly sliced raw fillet of beef, has not previously been associated with outbreaks, but should be considered a high-risk food item. This outbreak was one of two in different European Union (EU) countries traced back to beef from one company in a third EU country. This underscores the importance of efficient international Salmonella surveillance and food-safety control systems enabling timely interventions within the EU.

Background Asthma has been reported to be rare among Inuits, but so far total and specific IgE levels have never been determined in arctic populations. Objective To determine the prevalence of atopy in children living in an arctic environment, and to examine whether atopy and total IgE levels were associated with parental place of birth, as a measure of ethnicity, and travel history. Material and Methods All schoolchildren in Sisimiut, a community on the West coast of Greenland, were screened for atopy. Blood samples were analysed for total IgE and for specific IgE against inhalant and food allergens. Information on place of birth of children and their parents was obtained from national registries. Information on travel history was obtained from self-administered questionnaires. Results A total of 1031 schoolchildren aged 5 to 18 years had a blood sample drawn (85% of available children for the study). Of these, 151 (14.6%) children were sensitized to at least one inhalant allergen and 42 (4.1%) to at least one food allergen. Sensitization to grass was most common, whereas sensitization to mugwort, birch, animal-dander and house-dust mite was infrequent. Children whose parents were both born abroad had a higher risk of sensitization to inhalant allergens compared with children born of Greenlandic parents (OR = 8.6, 95% CI 2.8–27.1). Furthermore, children who had been abroad had a higher risk of sensitization towards pollen (OR = 1.6, 95% CI 1.0–2.5) and animal-dander (OR = 2.1, 95% CI 1.0–4.6) after adjustment for confounders. Both atopic and non-atopic children demonstrated high levels of total IgE (medians of 251 and 58 kU/L). Conclusions Compared with European findings Greenlandic children have high levels of total IgE but a low prevalence of allergic sensitization towards inhalant allergens. This may be due to a low genetic susceptibility to atopy and less allergen exposure, as well as to living conditions in an arctic environment.

We estimated the incidence and mortality of bacteraemia in the County of North Jutland and examined factors that could explain the changes observed. A population-based survey of bacteraemia was conducted in the Danish County of North Jutland during 1981-1994. Data were retrieved from a regional bacteraemia register. The mortality was determined through linkage to the Danish Civil Registration System. A total of 7198 bacteraemias were detected, and the annual incidence increased from 76 per 100,000 person-years in 1981 to 153 in 1994. One major determining factor was a change in blood culture system with a higher volume of blood per sample, but annual numbers of blood cultures also increased. The 30-day mortality rate increased from 17 to 40 per 100,000 person-years during the study period, whereas the case-fatality rate remained constant (23.6%; 95% confidence intervals 22.6%-24.6%). The number of bacteraemias increased significantly. This observation could be explained only partly by changes in demography, in blood culture system, and in diagnostic activity. The case fatality rate remained constant despite the fact that more people were diagnosed with bacteraemia ; this indicates that, with recent blood culture practice, more clinically significant bacteraemias are diagnosed.

Objective:To assess the data quality of septicemia and sepsis registration in a hospital discharge registry in the County of Northern Jutland, Denmark.Design:Comparison of data from the discharge registry of an 880-bed, public, urban hospital in the County of Northern Jutland with data from a computerized bac-teremia database at the regional department of clinical microbiology.Setting:Urban hospital with approximately 45,000 admissions per year.Patients:The study included 406 episodes of bac-teremia in the bacteremia database and 83 discharges with the diagnosis of septicemia registered in the hospital discharge registry between January 1, 1994, and December 31, 1994.Interventions:None.Results:Eighteen episodes were registered in both the hospital discharge registry and the bacteremia database. Using the bacteremia database as reference standard, the sensitivity for the diagnosis of septicemia in the hospital discharge registry was 4.4% (18/406; 95% confidence intervals [CI95, 2.4%-6.4%]). By review of hospital records, we estimated the positive predictive value of septicemia registration in the hospital discharge registry as 21.7% (18/83; CI95, 12.8%-30.5%). No blood culture had been obtained in 44.4% (36/81; CI95, 33.6%-55.3%) of the cases with a discharge diagnosis of septicemia. In 33.3% (27/81; CI95, 23.1%-43.6%), the discharge diagnosis of septicemia was given, although blood cultures were negative.Conclusions:The hospital discharge registry revealed numerous misclassifications, and the system was found not suited for surveillance of, or research in, bacteremia at present

In 1995 an epidemic caused by a mucoid group A streptococcus strain broke out among persons with mental handicaps in Copenhagen. Ninety persons, of whom 73% were mentally handicapped, fell ill with streptococcal infections. Four mentally handicapped persons died and the epidemic lasted 5 months. Cases appeared at 13 institutions from a total of 111 in Copenhagen. The infection control functions rested with the Public Health Offices of the City and the County of Copenhagen, but an ad hoc joint task force comprising also representatives from the National Board of Health and Statens Serum Institut made the neccesary recommandations on these issues. Prompt and accurate information to the authorities, the health service, relatives, staff and the public was disseminated and proved essential. Health staff in the services for persons with mental handicaps has decreased over recent years, but the remaining nursing staff played an essential role in recognizing the outbreak at an early stage as well as assisting in the control of spread. Knowledge about hygiene, infections and infection control is lacking among mentally handicapped individuals and often among the non-health educated staff of the service. We want to warn against a further weakening of the role of health staff.

Some Aerococcus-like organisms (ALOs) have recently been described in Denmark. The bacteria were originally isolated from the urine of elderly patients with urinary tract infections. Since 1987, we have identified 17 cases of bacteremia/septicemia in which ALOs have been isolated in pure culture of blood ; we report the data from these cases. Six of the patients presented with endocarditis, eight presented with urosepticemia, and three presented with septicemia. In all but one of the reports, the urinary tract was suspected as the focus of infection, and ALOs were isolated from the urine of nine patients. All but one patient had predisposing illnesses ; these were predominantly of urinary or cardiac origin. Five patients died of their infection, two survived the infection but eventually died during hospitalization, and 10 recovered. All of the patients received adequate antimicrobial therapy.

Background Parasitic helminths have been shown to reduce inflammation in most experimental models of allergic disease, and this effect is mediated via cytokine responses. However, in humans, the effects of controlled helminth infection on cytokine responses during allergy have not been studied. Objective The aim was to investigate whether infection with the nematode parasite Trichuris suis alters systemic cytokine levels, cellular cytokine responses to parasite antigens and pollen allergens and/or the cytokine profile of allergic individuals. Methods In a randomized double-blinded placebo-controlled clinical trial (UMIN trial registry, Registration no. R000001298, Trial ID UMIN000001070, URL: http://www.umin.ac.jp/map/english), adults with grass pollen-induced allergic rhinitis received three weekly doses of 2500 Trichuris suis ova (n = 45) or placebo (n = 44) over 6 months. IFN-γ, TNF-α, IL-4, IL-5, IL-10 and IL-13 were quantified via cytometric bead array in plasma. Cytokines, including active TGF-β, were also quantified in supernatants from peripheral blood mononuclear cells cultured with parasite antigens or pollen allergens before, during and after the grass pollen season for a sub-cohort of randomized participants (T. suis ova-treated, n = 12, Placebo-treated, n = 10). Results Helminth infection induced a Th2-polarized cytokine response comprising elevated plasma IL-5 and parasite-specific IL-4, IL-5 and IL-13, and a global shift in the profile of systemic cytokine responses. Infection also elicited high levels of the regulatory cytokine IL-10 in response to T. suis antigens. Despite increased production of T. suis-specific cytokines in T. suis ova-treated participants, allergen-specific cytokine responses during the grass pollen season and the global profile of PBMC cytokine responses were not affected by T. suis ova treatment. Conclusions and clinical relevance This study suggests that cytokines induced by Trichuris suis ova treatment do not alter allergic reactivity to pollen during the peak of allergic rhinitis symptoms.

Background Antibiotic prophylaxis (AP) is an important measure in preventing health care–associated urinary tract infections (HAUTIs). Despite regional variations in the bacterial spectrum and antibiotic susceptibility patterns, guideline recommendations are usually given on an international level. Objective To describe the use of AP in urology departments and relate this to relevant parameters such as country, type of hospital, and European Association of Urology guideline recommendations. Design, setting, and participants Data from the Global Prevalence Study on Infections in Urology for the period 2005–2010 were analysed to evaluate the use of antibiotics in general and AP for urologic procedures. Of the 13 723 patients enrolled, 8178 received antibiotics on the study days. Outcome measurements and statistical analysis Study data were imported from the Web-based survey into Microsoft Access and exported into SPSS v.17.0. The data were then coded and analysed. The Pearson chi-Square test was used to compare categorical data and a probability level of 5% was considered significant. Multiple logistic regression analysis was used to define significantly different variables in multiple set categories. Results and limitations Questions on AP were answered on 8370 forms and 6306 (75.3%) investigators reported their routine application of AP. Routine AP was highest in Latin America ( n = 337; 84%), followed by Asia ( n = 1338; 86%), Africa ( n = 234; 85%), and Europe ( n = 4116; 67%). The antibiotics most frequently used for AP were second-generation cephalosporins, ciprofloxacin, cefotaxime, and amoxicillin plus beta-lactamase inhibitor. Conclusions There were significant differences between countries/regions and types of hospitals, both in using AP for clean procedures and in the types of antibiotics used. AP was not always consistent with recommended guidelines.

BACKGROUND: The yield of blood cultures is approximately 10%. This could be caused by inaccurate prediction of patients with bloodstream infection (BSI).OBJECTIVES: To evaluate the usability of systemic inflammatory response syndrome (SIRS) or biochemical analyses as predictors for positive blood culture.METHODS: We conducted a prospective cohort study at a Danish regional hospital from February 1 to April 30, 2010. All adult patients were included on the first time blood cultures were sampled during admission. Data were obtained from medical records, databases on microbiology, biochemistry, and antibiotic treatment. Data included time of admission, date and result of blood culture, results of biochemical analyses, and clinical measurements on the day of blood culture. Prediction of BSI was analyzed according to both individual parameters and parameters combined in different sepsis score groups. Associations were calculated using multiple logistic regression.RESULTS: Patients with BSI (68 patients) were compared to patients without BSI (828 patients). Respiratory rate, body temperature, and C-reactive protein were strongest associated with BSI, with adjusted odds ratio (OR) 5.42, 95% confidence interval (CI) 1.13-25.9; OR 2.55, 95% CI 1.34-4.87; and OR 6.06, 95% CI 0.82-44.6, respectively. SIRS was associated with BSI, with crude OR 7.25, 95% CI 1.75-30.1. Neutrophil count and p-carbamide were not associated with BSI: adjusted OR 0.88, 95% CI 0.36-2.13 and OR 1.44, 95% CI 0.82-2.52, respectively. Only one of the sepsis score groups was associated with BSI: crude OR 2.13, 95% CI 1.08-4.19.CONCLUSIONS: SIRS is an adequate predictor of BSI. By contrast, biochemical parameters were not useful as predictors of BSI.

Background Long-term tunneled central venous catheters (CVCs) are often the source of catheter-associated bloodstream infections (CABSIs), which may be difficult to eradicate and may lead to premature catheter removal. Procedure This prospective controlled study used instillation of 2 M hydrochloric acid (HCl) as an adjuvant to the intravenous antibiotic treatment of children with bacteremia and compared the results with those from the immediate preceding period. The primary outcome variable was infection-related CVC removal within 100 days of bacteremia. Only patients with double lumen Hickman CVC with external tubings were included. Results During a period of 36 months, 109 episodes of bacteremia were treated, 51 during the period where HCl was not used and 58 during the period where HCl was used. Forty-two out of 58 bacteremias were treated with HCl during the "HCl period." An intention-to-treat analysis showed that the median time to infection-related CVC removal was significantly longer during the HCl period compared with the non-HCl period (94 d vs. 12.5 d). At day 100 significantly more CVCs remained in place compared with the non-HCl period. Of the 42 CVCs treated with HCl, 2 had to be removed because of infection before day 30 and further 7 CVCs were removed before day 100. There was no difference in the occurrence of new bacteremias within the first 30 days of bacteremia in the 2 groups. Conclusion HCl may successfully supplement intravenous antibiotics in the treatment of CABSI and contribute to CVC salvage.

Udgivelsesdato: 2010-Feb We hypothesized that preceding zoonotic Salmonella or Campylobacter gastroenteritis aggravated the prognosis in cancer patients. Exposed patients comprised all of those diagnosed with first-time Salmonella/Campylobacter gastroenteritis from 1991 and with first-time cancer diagnosis thereafter (through 2003) in two Danish counties. These patients were matched for main cancer type, gender, age and calendar period to unexposed cancer patients, i.e. those without Salmonella/Campylobacter gastroenteritis. We compared cancer stage by age- and comorbidity-adjusted logistic regression analysis, survival by comorbidity-adjusted Cox's regression analysis and mortality dependent on the time period between Salmonella/Campylobacter gastroenteritis and cancer by spline regression curves. The study cohort comprised 272 Salmonella/Campylobacter-exposed cancer patients and 2681 unexposed cancer patients. Prevalence odds ratios [95% confidence intervals (CI)] in exposed as compared with unexposed patients were 0.96 (0.74-1.25) for localized tumours, 1.15 (0.87-1.54) for regional spread and 1.14 (0.84-1.55) for metastases. Adjusted mortality rate ratios (95% CI) were 0.93 (0.75-1.16) for 0-1 year, 1.08 (0.84-1.39) for 2-5 years and 1.02 (0.60-1.73) for the remaining period. Mortality estimates did not change in relation to the time period between gastroenteritis and cancer. Salmonella/Campylobacter gastroenteritis prior to cancer was associated with neither the cancer stage nor a poorer prognosis.

Udgivelsesdato: 2010-Mar The role of bacterial genes in the determination of the clinical spectrum of Campylobacter jejuni infection is unclear. We compared clinical isolates from invasive blood-stream infection with stool isolates from gastroenteritis and found no association of the putative virulence genes iam, capA, virB and cdtB with clinical presentation.

acquired if it began more than 48 hours after hospitalization and was not present at or incubating before hospital admission; BSIs in patients readmitted within 7 days after microbiologically confirmed HCR-BSI were not considered new cases of HCR-BSI. BSIs were identified from the microbiological laboratory information system and included primary and secondary cases. The Danish civil registration numbers of patients with microbiologically confirmed HCR-BSI were used to review electronic patient records for signs and symptoms of BSI. Data on the number of bed-days, the times of admission and readmission, and the number of admissions were compiled from the hospital’s administrative database. The amount of hand rub used per 1,000 bed-days (represented on a log scale) was analyzed jointly with the number of new cases of HCR-BSI per 1,000 bed-days. We used a vector autoregression model, with the amount of hand rub used and the number of incident HCR-BSIs in the preceding 2 months

Background & Aims Various commensal enteric and potentially pathogenic bacteria may be involved in the pathogenesis of inflammatory bowel diseases (IBD). We compared the risk of IBD between a cohort of patients with documented Salmonella or Campylobacter gastroenteritis and an age- and gender-matched control group from the same population in Denmark. Methods We identified 13,324 patients with Salmonella / Campylobacter gastroenteritis from laboratory registries in North Jutland and Aarhus counties, Denmark, from 1991 through 2003, and 26,648 unexposed controls from the same counties. Of these, 176 exposed patients with IBD before the infection, their 352 unexposed controls, and 80 unexposed individuals with IBD before the Salmonella / Campylobacter infection were excluded. The final study cohort of 13,148 exposed and 26,216 unexposed individuals were followed for up to 15 years (mean, 7.5 years). Results A first-time diagnosis of IBD was reported in 107 exposed (1.2%) and 73 unexposed individuals (0.5%). By age, gender, and comorbidity adjusted Cox proportional hazards regression analysis, the hazard ratio (95% confidence interval) for IBD was 2.9 (2.2–3.9) for the whole period and 1.9 (1.4–2.6) if the first year after the Salmonella / Campylobacter infection was excluded. The increased risk in exposed subjects was observed throughout the 15-year observation period. The increased risk was similar for Salmonella (n = 6463) and Campylobacter (n = 6685) and for a first-time diagnosis of Crohn's disease (n = 47) and ulcerative colitis (n = 133). Conclusions In our population-based cohort study with complete follow-up, an increased risk of IBD was demonstrated in individuals notified in laboratory registries with an episode of Salmonella / Campylobacter gastroenteritis.

Udgivelsesdato: 2009 We hypothesised that haematological malignancies increase the risk of acquiring zoonotic Salmonella or Campylobacter gastroenteritis. The population-based study comprised all first-time Salmonella/Campylobacter gastroenteritis cases in two Danish counties (1991-2003), with age- and gender-matched controls from the background population. We linked the study cohort to registries to obtain data on malignancies, chemotherapy (yes/no), and main comorbidities diagnosed before Salmonella/Campylobacter gastroenteritis. Based on this design, we determined incidence rate ratios (IRR) in conditional logistic regression analyses, and we used weighted mean regression curves to evaluate fluctuations in risk 0-5 years after the malignancy diagnosis. Sixty-eight of 13,324 cases (0.5%) and 29 of 26,648 controls (0.1%) had haematological malignancy before their Salmonella/Campylobacter gastroenteritis. Comorbidity-adjusted IRR for Salmonella/Campylobacter gastroenteritis in patients with haematological malignancy as compared to patients without malignancy were 4.46 [95% confidence intervals (CI), 2.88-6.90] for all individuals, 8.33 (95% CI, 4.31-16.1) for Salmonella, and 2.17 (95% CI, 1.15-4.08) for Campylobacter. Stratification on chemotherapy treatment did not change these estimates. In time-related analyses, IRR were 7-8 in the first 2 years after the haematological malignancy diagnosis and 4-5 in the following 3 years. Patients with haematological malignancy had increased long-term risk of enquiring Salmonella or Campylobacter gastroenteritis.

Udgivelsesdato: 2009-Sep BACKGROUND: Since 2004, we have promoted alcohol-based hand rubbing (HR) with an e-learning program (ELP) among hospital staff. This study sought to determine whether an ELP improves adherence to correct HR. METHODS: This was a cohort study of staff members at Aarhus University Hospital, Skejby, Denmark who completed the ELP and were repeatedly observed for correct HR before and after clinical procedures in 2006 and/or 2007. RESULTS: Of the 496 participants, 13% completed the ELP in both 2006 and 2007, 29% completed the ELP only in 2006, 15% completed the ELP only in 2007, and 43% never completed the ELP. Compared with noncompleters, completers of the 2006 and 2007 ELP had a significantly higher adherence to correct HR both before clinical procedures (odds ratio [OR] = 1.54; 95% confidence interval [CI] = 1.11 to 2.13) and after clinical procedures (OR = 1.40; 95% CI = 1.03 to 1.89). Time since completing the ELP seemed to be inversely associated with adherence to correct HR. CONCLUSION: Completion of an ELP may have a positive impact on the performance of correct HR. The demands of lifelong education and training of hospital staff may call for the use of an ELP as a supplement to existing efforts aimed at improving HR to help prevent health care-related infections.

A literature review shows that hand disinfection is superior to hand washing concerning the elimination of microorganisms. Alcohol-based hand rubs quickly and easily reduce the number of microorganisms on hands. It is important that healthcare professionals prevent the transmission of microorganisms by hand disinfection before and after patient-related procedures. Factors that influence adherence to hand disinfection are discussed.

Udgivelsesdato: 2008-Oct We evaluated hand antisepsis in clinical practice at Aarhus University Hospital in Skejby, Denmark. The rate of compliance with the correct use of alcohol-based hand rub exceeded 55% of all routine clinical procedures observed. With the correct use of alcohol-based hand rub by hospital staff, bacterial counts were reduced by 90% before and 82% after a clinical procedure; with incorrect use, the bacterial counts were reduced by 60% before and 54% after a clinical procedure.

Summary Objectives To evaluate the impact of age and comorbidity on the risk and prognosis of zoonotic Salmonella and Campylobacter gastroenteritis in elderly individuals. Methods Registry-based study comprising all first-time zoonotic Salmonella / Campylobacter gastroenteritis infections in two Danish counties from 1991 through 2003. Cases were elderly (≥65 years) Salmonella / Campylobacter patients. Younger Salmonella / Campylobacter patients and age and gender matched individuals were reference persons. Results There were 13,324 Salmonella / Campylobacter patients (including 1226 elderly patients) and 26,648 matched reference persons. Elderly Salmonella / Campylobacter patients had more comorbidity than their matched reference persons (OR [95% CI]: 1.56 [1.35–1.80]) and comorbidity adjusted mortality rate ratios (95% CI) were 11.4 (5.1–25.4), 1.9 (1.4–2.6), and 1.3 (0.9–1.9) at day 0–30, 31–180, and 181–365, respectively. The differences in crude 365-day mortality increased with age when Salmonella / Campylobacter patients and reference persons without comorbidity were compared. The independent impact of age was less clear for individuals with comorbidity. There were no differences in comorbidity or survival between non-hospitalized elderly patients and their matched reference persons. Conclusions Elderly hospitalized Salmonella / Campylobacter patients had higher comorbidity and 1-year mortality than the background population. The excess 30-day mortality elucidated the prognostic role of the Salmonella / Campylobacter infection per se .

OBJECTIVE: Clostridium difficile is a major cause of nosocomial infectious diarrhoea. Treatment of C. difficile infection (CDI) depends on disease severity. A combination of vancomycin and metronidazole is often recommended in severe cases. The aim of this study was to examine, in a murine model of CDI, if mice treated with a combination of vancomycin and metronidazole had a better clinical outcome than mice treated with vancomycin or metronidazole alone.DESIGN: C57BL/6J mice pretreated with an antimicrobial mixture were challenged with C. difficile VPI 10463 or phosphate-buffered saline by oral gavage. After the challenge, the mice were treated with placebo, vancomycin, metronidazole or a combination of vancomycin and metronidazole for 10 days. The mice were monitored for 20 days with weight and a clinical score. Stool samples were examined for C. difficile spore load and presence of C. difficile toxins.RESULTS: None of the mice in the vancomycin-treated group died during the treatment phase compared to a mortality of 17%, 33% and 55% in the combination, metronidazole and infected control group, respectively. Mice treated with vancomycin alone or in combination with metronidazole recovered from CDI faster than mice treated with metronidazole alone. However, after discontinuation of treatment, vancomycin-treated and combination-treated mice succumbed to clinical and bacteriological relapse.CONCLUSIONS: Mice treated with vancomycin alone had a better clinical outcome in the treatment phase of CDI than mice treated with metronidazole alone. A combination of vancomycin and metronidazole did not improve the clinical outcome when compared to treatment with vancomycin alone.TRIAL REGISTRATION NUMBER: The trial registration number from the Danish Experimental Animal Inspectorate is J number 2012-15-2934-00422.

This national population-based study was conducted as part of the development of a national automated surveillance system for hospital-acquired bacteraemia and ascertains the utilization of blood cultures (BCs). A primary objective was to understand how local differences may affect interpretation of nationwide surveillance for bacteraemia. From the Danish Microbiology Database, we retrieved all BCs taken between 2010 and 2013 and linked these to admission data from the National Patient Registry. In total, 4 587 295 admissions were registered, and in 11%, at least one BC was taken. Almost 50% of BCs were taken at admission. The chance of having a BC taken declined over the next days but increased after 4 days of admission. Data linkage identified 876 290 days on which at least one BC was taken; 6.4% yielded positive results. Ten species, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae, Enterococcus faecium, Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans, Enterobacter cloacae and Klebsiella oxytoca, accounted for 74.7% of agents for this purpose classified as pathogenic. An increase in BCs and positive BCs was observed over time, particularly among older patients. BCs showed a seasonal pattern overall and for S. pneumoniae particularly. A predominance of male patients was seen for bacteraemias due to S. aureus, E. faecium and K. pneumoniae. Minor differences in BCs and positive BCs between departments of clinical microbiology underpin the rationale of a future automated surveillance for bacteraemia. The study also provides important knowledge for interpretation of surveillance of invasive infections more generally.

A problem in clinical microbiology is that of inappropriate antibiotic therapy. Various decision-support systems have been proposed to aid physicians in this domain, and we discuss the a priori advantages of using a probabilistic network over other approaches. The Treat project uses a probabilistic network to combine clinical signs, symptoms and laboratory results, and we discuss the problem of obtaining probabilities for the network. Finally, we consider how such a system can be tested in clinical practice and outline the results of our tests.