Universal risk assessment upon hospital admission for screening of carriage with multidrug-resistant micro-organisms in a Dutch tertiary care centre.

BACKGROUND: In Dutch hospitals a six-point questionnaire is currently mandatory for risk assessment to identify carriers of multidrug-resistant organisms (MDROs) at the time of hospitalization. Presence of one or more risk factors is followed by pre-emptive isolation and microbiological culturing. AIM: To evaluate the yield of the universal risk assessment in identifying MDRO carriers upon hospitalization. METHODS: A cross-sectional study was performed using routine healthcare data in a Dutch tertiary hospital between January 1st, 2015 and August 1st, 2019. MDRO risk assessment upon hospitalization included assessment of: known MDRO carriage, previous hospitalization in another Dutch hospital during an outbreak or a foreign hospital, living in an asylum centre, exposure to livestock farming, and household membership of a meticillin-resistant Staphylococcus aureus carrier. FINDINGS: In total, 144,051 admissions of 84,485 unique patients were included; 4480 (3.1%) admissions had a positive MDRO risk assessment. In 1516 (34%) admissions microbiological screening was performed, of which 341 (23%) yielded MDRO. Eighty-one patients were categorized as new MDRO carriers, as identified through MDRO risk assessment, reflecting 0.06% (95% confidence interval: 0.04-0.07) of all admissions and 1.8% (1.4-2.2) of those with positive risk assessment. As a result, the number of 'MDRO risk assessments needed to perform' and individual 'MDRO questions needed to ask' to detect one new MDRO carrier upon hospitalization were 1778 and 10,420, respectively. CONCLUSION: The yield of the current strategy of MDRO risk assessment upon hospitalization is limited and it needs thorough reconsideration.

Risk factors for the acquisition of OXA-48-producing Enterobacteriaceae in a hospital outbreak setting: a matched case-control study.

OBJECTIVES: In the context of a large outbreak of OXA-48-producing Enterobacteriaceae (OXA-E) in a Dutch hospital we determined risk factors for acquisition of OXA-E. PATIENTS AND METHODS: A matched case-control study was performed in which cases (culture positive for OXA-E) were matched 1:3 to controls (culture negative for OXA-E) based on hospital ward, index date (±1 week) and time exposed in the hospital (best match). Stratified analyses were performed for patients with OXA-E producing and not producing ESBL. Potential risk factors included age, gender, surgery and ICU admission within 30 days preceding the index date, presence of comorbidities and in-hospital antibiotic treatment within 30 days preceding the index date. Data analysis was performed using multivariable conditional logistic regression with Firth correction. RESULTS: In total, 73 cases were matched to 211 controls. In the multivariable conditional logistic regression model, male gender (OR 2.63, 95% CI 1.25-5.53), age (per year increase, OR 1.03, 95% CI 1.00-1.05) and use of fluoroquinolones within 30 days preceding the index date (OR 2.98, 95% CI 1.06-8.41) were risk factors for acquisition of OXA-E. In the stratified multivariable conditional logistic regression model, quinolone use was a risk factor for the acquisition of ESBL-producing OXA-E and surgery was a risk factor for the acquisition of non-ESBL-producing OXA-E. CONCLUSIONS: During a large, hospital-wide OXA-E outbreak, male gender, age and previous use of fluoroquinolones were risk factors for acquisition of OXA-E. These findings may help in optimizing screening and isolation strategies in future OXA-E outbreaks.

Rapid diagnostic testing of methicillin-resistant Staphylococcus aureus carriage at different anatomical sites: costs and benefits of less extensive screening regimens.

Multiple body site screening and pre-emptive isolation of patients at risk for methicillin-resistant Staphylococcus aureus (MRSA) carriage are considered essential for control of nosocomial spread. The relative importance of extranasal screening when using rapid diagnostic testing (RDT) is unknown. Using data from a multicentre study evaluating BD GeneOhm™ MRSA PCR (IDI), Xpert MRSA (GeneXpert) and chromogenic agar, added to conventional cultures, we determined cost-effectiveness assuming isolation measures would have been based on RDT results of different hypothetical screening regimes. Costs per isolation day avoided were calculated for regimes with single or less extensive multiple site RDT, regimes without conventional back-up cultures and when PCR would have been performed with pooling of swabs. Among 1764 patients at risk, MRSA prevalence was 3.3% (n = 59). In all scenarios the negative predictive value is above 98.4%. With back-up cultures of all sites as a reference, the costs per isolation day avoided were €15.19, €30.83 and €45.37 with 'nares only' screening using chromogenic agar, IDI and GeneXpert, respectively, as compared with €19.95, €95.77 and €125.43 per isolation day avoided when all body sites had been screened. Without back-up cultures costs per isolation day avoided using chromogenic agar would range from €9.24 to €76.18 when costs per false-negative RDT range from €5000 up to €50 000; costs for molecular screening methods would be higher in all scenarios evaluated. In conclusion, in a low endemic setting chromogenic agar screening added to multiple site conventional cultures is the most cost-effective MRSA screening strategy.

[Methicillin-resistant Staphylococcus aureus of livestock origin in Dutch hospitals: high-risk patients need only to be investigated if admitted to hospital]. / Meticillineresistente Staphylococcus aureus afkomstig uit de veestapel in Nederlandse ziekenhuizen: risicopatiënten alleen controleren bij eventuele ziekenhuisopname.

OBJECTIVE: To determine the incidence and prevalence of carriage of methicillin-resistent Staphylococcus aureus (MRSA) in patients and hospital personnel, and to examine the consequences of the revised Dutch MRSA guideline with respect to patients who have frequent contact with pigs or calves (in the course of their work). DESIGN: Retrospective and prospective observational study using questionnaires. METHOD: Since July 2006 patients who have contact with living pigs or calves have been regarded as a high-risk group for MRSA carriage, after it was established that this occupational group had an increased chance of carriage of the so-called non-typable MRSA (NT-MRSA). An inventory was made of incidence and prevalence of MRSA carriage in patients and hospital personnel, and of the consequences of the new MRSA policy, for the period July-December 2006. RESULTS: Information was obtained from 58 Dutch hospitals. On January 1 2007, 37 (64%) hospitals had changed their MRSA policy; 22% of the hospitals it was applied in accordance with the MRSA guideline. The new guideline resulted in an increase of MRSA screenings by 15% and of detected MRSA carriers by 44%. 73% of all MRSA screenings took place in the out-patients department. In regions with high pig-density the incidence of NT-MRSA was 12% in patients with risk factors for carriage. In 49% of the hospitals one or more NT-MRSA carriers were detected (range 1-19 carriers). Possible transmission of NT-MRSA in hospital was shown in 3 of 1,007 (0.3%) hospital personnel, but in none of the 183 fellow-patients, examined. In the same period transmission of typable MRSA was demonstrated in 41 of 2,019 (2.0%) patients and 33 of 5,190 (0.6%) of hospital personnel examined. Prevalence of NT-MRSA carriage in 6,197 screened hospital personnel was 0.05% (n = 3). CONCLUSION: The revised Dutch MRSA guideline lead to an increase in the number of MRSA screenings by 15%, particularly in the out-patients department, and to an increase in the number of detected MRSA carriers by 44%. During 306 months of observation no patient-to-patient transmission ofNT-MRSA was demonstrated.

Prevalence of hospital-acquired infections during successive surveillance surveys conducted at a university hospital in the Netherlands.

OBJECTIVE: To monitor hospital-wide trends in the prevalence of hospital-acquired infections (HAIs) in order to identify areas where the risk of infection is increasing. METHODS: Successive surveillance surveys were conducted twice yearly, from November 2001 until May 2004, to determine the prevalence of HAIs at 2 Dutch hospitals, using Centers for Disease Control and Prevention criteria. RESULTS: In all, 340 HAIs were observed in 295 (11.1%) of 2,661 patients surveyed. The overall prevalence per survey varied from 10.2% to 15.6%, with no significant differences between successive surveys. In the surgical department, the prevalence of HAIs increased from 10.8 cases per 100 surgeries in November 2001 to 20.4 cases per 100 surgeries in May 2002. Further analysis revealed a high prevalence of surgical site infection among patients who had an orthopedic procedure performed. In the neurology-neurosurgery department, the prevalence increased from 13.0 cases per 100 patients in May 2002 to 26.6 cases per 100 patients in May 2003 and involved several types of infection. Further analysis retrieved exceptionally high incidences of infections associated with cerebrospinal fluid drainage. Specific infection control interventions were developed and implemented in both departments. The total cost of the surveys was estimated to be euro9,100 per year. CONCLUSION: Successive performance of surveillance surveys is a simple and cheap method to monitor the prevalence of infection throughout the hospital and appeared instrumental in identifying 2 departments with increased infection rates.

Costs associated with a strict policy to eradicate methicillin-resistant Staphylococcus aureus in a Dutch University Medical Center: a 10-year survey.

Although the Dutch policy to eradicate methicillin-resistant Staphylococcus aureus (MRSA) is very strict compared to policies employed in other countries, it has proven to be successful epidemiologically (incidence of MRSA in the Netherlands, <0.5%). The present study was performed to investigate both the financial and the logistical consequences of this strict, so-called "search and destroy" policy in the Netherlands. The data were based on a 10-year survey (1991-2000) of screening, surveillance, and outbreaks at the University Medical Center Utrecht. The consequences of the policy were determined by a panel comprising physicians from the Department of Surgery, the Department of Medical Microbiology, Subdivision Hospital Hygiene and Infection Prevention, the Department of Pharmacy, and Household Services. The costs associated with the policy were also calculated, including those for additional (disposable) material, cultures, specific medication, decontamination, and closing of the wards. Over the course of the 10 years, implementation of the MRSA policy resulted in more than 2,265 lost hospitalization days. In addition, the wards had to be closed 48 times, 29 healthcare workers had to temporarily discontinue working, and 78,000 additional cultures had to be performed. The total cost reached 6 million Dutch guilders (euro 2,800,000). The financial and logistical consequences were then compared to those in a hypothetical situation without the "search and destroy" policy. In such a situation, the hospital would be faced with an increased incidence of MRSA, vancomycin intermediate-susceptible Staphylococcus aureus, and vancomycin-resistant enterococci. The costs associated with the use of alternative antibiotics, required in a scenario of high endemic-level MRSA, would be at least twice as high as the costs expended in the actual situation, thus demonstrating that a strict MRSA policy is financially worthwhile.

Lipopolysaccharide-coated erythrocytes activate human neutrophils via CD14 while subsequent binding is through CD11b/CD18.

Interaction of LPS with monocytes and neutrophils is known to occur via CD14 and is strongly enhanced by LPS-binding protein (LBP). Integrins as well as CD14 play a role in the interaction of erythrocytes (E) coated with LPS or whole Gram-negative bacteria with phagocytes. We reasoned that the density of LPS on a particle is an important determinant in these interactions. Therefore, E were coated with different concentrations of LPS (ELPS). The binding of these ELPS to neutrophils was evaluated by flow cytometry. Simultaneously, we measured fMLP receptor expression to evaluate neutrophil activation. ELPS only bound to neutrophils in the presence of LBP. Blocking CD14 inhibited both activation and binding, whereas blocking complement (C) receptor 3 (CR3) inhibited binding but not activation. TNF activation restored ELPS binding in CD14-blocked cells but not in cells in which CR3 was blocked. Salmonella minnesota did bind to neutrophils independent of CR3 or CD14. The addition of LBP enhanced binding twofold, and this surplus was dependent upon CD14 but not on CR3. We conclude that ELPS interact with neutrophils via CD14, initially giving rise to cell activation; subsequently, binding is solely mediated by activated CR3.

Saturable CD14-dependent binding of fluorescein-labeled lipopolysaccharide to human monocytes.

We used rough lipopolysaccharide (ReLPS) to construct a fluorescein-labeled LPS (FITC-LPS) with a very high labeling efficiency that bound to isolated human monocytes in a CD14-dependent fashion and that in this respect behaved indistinctively from native LPS. The CD14-dependent binding could be inhibited either by a 1,000-fold excess of unlabeled LPS or by polymyxin B, bactericidal/permeability-increasing protein, cationic protein 18, or soluble CD14. Although this FITC-LPS preparation no longer possessed the ability to prime neutrophils for the production of reactive oxygen species or to stimulate human monocytes to produce tumor necrosis factor, activation of the Limulus amoebocyte lysate cascade was comparable to activation by native LPS. Binding to monocytes was enhanced by human pooled serum (HPS) or LPS-binding protein (LBP) for LPS concentrations up to 100 ng/ml and was completely CD14 dependent. For LPS concentrations exceeding 100 ng/ml, binding was still partially CD14 dependent, but not HPS or LBP dependent. CD14-dependent association of LPS with monocytes was shown to be totally saturable. In conclusion, we found an HPS- or LBP-dependent binding of FITC-LPS to monocytes that was CD14 dependent at up to 100 ng of LPS per ml, and saturation of binding was shown.