Search

Intensive care units (ICUs) play an important role in the epidemiology of methicillin-resistant Staphyloccocus aureus (MRSA). Although successful interventions are multi-modal, the relative efficacy of single measures remains unknown. We developed a discrete time, individual-based, stochastic mathematical model calibrated on cross-transmission observed through prospective surveillance to explore the transmission dynamics of MRSA in a medical ICU. Most input parameters were derived from locally acquired data. After fitting the model to the 46 observed cross-transmission events and performing sensitivity analysis, several screening and isolation policies were evaluated by simulating the number of cross-transmissions and isolation-days. The number of all cross-transmission events increased from 54 to 72 if only patients with a past history of MRSA colonization are screened and isolated at admission, to 75 if isolation is put in place only after the results of the admission screening become available, to 82 in the absence of admission screening and with a similar reactive isolation policy, and to 95 when no isolation policy is in place. The method used (culture or polymerase chain reaction) for admission screening had no impact on the number of cross-transmissions. Systematic regular screening during ICU stay provides no added-value, but aggressive admission screening and isolation effectively reduce the number of cross-transmissions. Critically, colonized healthcare workers may play an important role in MRSA transmission and their screening should be reinforced.

Background: Research suggests that patients could improve healthcare workers' compliance with hand hygiene recommendations by reminding them to cleanse their hands., Objective: To assess patients' perceptions of a patient-participation program to improve healthcare workers' compliance with hand hygiene., Design: Cross-sectional survey of patient knowledge and perceptions of healthcare-associated infections, hand hygiene, and patient participation, defined as the active involvement of patients in various aspects of their health care., Setting: Large Swiss teaching hospital., Results: Of 194 patients who participated, most responded that they would not feel comfortable asking a nurse (148 respondents [76%]) or a physician (150 [77%]) to perform hand hygiene, and 57 (29%) believed that this would help prevent healthcare-associated infections. In contrast, an explicit invitation from a healthcare worker to ask about hand hygiene doubled the intention to ask a nurse (from 34% to 83% of respondents; P < .001) and to ask a physician (from 30% to 78%; P < .001). In multivariate analysis, being nonreligious, having an expansive personality, being concerned about healthcare-associated infections, and believing that patient participation would prevent healthcare-associated infections were associated with the intention to ask a nurse or a physician to perform hand hygiene (P < .05). Being of Jewish, Eastern Orthodox, or Buddhist faith was associated also with increased intention to ask a nurse (P < .05), compared with being of Christian faith., Conclusions: This study identifies several sociodemographic characteristics associated with the intention to ask nurses and physicians about hand hygiene and underscores the importance of a direct invitation from healthcare workers to increase patient participation and foster patient empowerment. These findings could guide the development of future hand hygiene-promotion strategies.

Objectives: Hand hygiene promotion interventions rarely result in sustained improvement, and an assessment of their impact on individual infection risk has been lacking. We sought to measure the impact of hand hygiene promotion on health care worker compliance and health care-associated infection risk among neonates., Methods: We conducted an intervention study with a 9-month follow-up among all of the health care workers at the neonatal unit of the Children's Hospital, University of Geneva Hospitals, between March 2001 and February 2004. A multifaceted hand hygiene education program was introduced with compliance assessed during successive observational surveys. Health care-associated infections were prospectively monitored, and genotypic relatedness of bloodstream pathogens was assessed by pulsed-field gel electrophoresis. A comparison of observed hand hygiene compliance and infection rates before, during, and after the intervention was conducted., Results: A total of 5325 opportunities for hand hygiene were observed. Overall compliance improved gradually from 42% to 55% across study phases. This trend remained significant after adjustment for possible confounders and paralleled the measured increase in hand-rub consumption (from 66.6 to 89.2 L per 1000 patient-days). A 9-month follow-up survey showed sustained improvement in compliance (54%), notably with direct patient contact (49% at baseline vs 64% at follow-up). Improved compliance was independently associated with infection risk reduction among very low birth weight neonates. Bacteremia caused by clonally related pathogens markedly decreased after the intervention., Conclusions: Hand hygiene promotion, guided by health care workers' perceptions, identification of the dynamics of bacterial contamination of health care workers' hands, and performance feedback, is effective in sustaining compliance improvement and is independently associated with infection risk reduction among high-risk neonates.

The authors compared a case-crossover design, a case-time-control design, and a cohort design to evaluate the effect of nurse staffing level on the risk of nosocomial infections. They evaluated two strategies, conditional logistic regression and generalized estimating equation, to analyze the case-crossover study. The study was performed among critically ill patients in the medical intensive care unit of the University of Geneva Hospitals, Geneva, Switzerland. Of 366 patients who stayed more than 7 days in the intensive care unit between 1999 and 2002, 144 developed an infection. The main reasons for admission were infectious (35.3%), cardiovascular (32.5%), and pulmonary (19.7%) conditions. A comparison of the three study designs showed that lower nurse staffing was associated with an approximately 50% increased risk of nosocomial infections. All analyses yielded similar estimates, except that the point estimate obtained by the conditional logistic regression used in the case-crossover design was biased away from unity; the generalized estimating equation yielded unbiased results and is the most appropriate technique for case-crossover designs. The case-crossover methodology in hospital epidemiology is a promising alternative to traditional approaches, but selection of the referent periods is challenging.

Objective: There is growing evidence that low nurse staffing jeopardizes quality of patient care. The objective of the study was to determine whether low staffing level increases the infection risk in critical care., Design: Observational, single-center, prospective cohort study., Setting: Medical intensive care unit of the University of Geneva Hospitals, Switzerland., Patients: All patients admitted over a 4-yr period., Interventions: None., Measurements and Main Results: Study variables included all infections acquired in critical care, daily nurse-to-patient ratio, demographic characteristics, admission diagnosis and severity score, comorbidities, daily individual exposure to invasive devices, and selected drugs. Of a cohort of 1,883 patients totaling 10,637 patient-days, 415 (22%) developed at least one healthcare-associated infection while in critical care. Overall infection rate was 64.5 episodes per 1000 patient-days. Infected patients experienced higher mortality with a longer duration of stay both in critical care and in the hospital than noninfected patients (all p < .001). Median 24-hr nurse-to-patient ratio was 1.9. Controlling for exposure to central venous catheter, mechanical ventilation, urinary catheter, and antibiotics, we found that higher staffing level was associated with a >30% infection risk reduction (incidence rate ratio, 0.69; 95% confidence interval, 0.50-0.95). We estimated that 26.7% of all infections could be avoided if the nurse-to-patient ratio was maintained >2.2., Conclusions: Staffing is a key determinant of healthcare-associated infection in critically ill patients. Assuming causality, a substantial proportion of all infections could be avoided if nurse staffing were to be maintained at a higher level.

Objective: An important problem that arises in hospitals is the monitoring and detection of nosocomial or hospital acquired infections (NIs). This paper describes a retrospective analysis of a prevalence survey of NIs done in the Geneva University Hospital. Our goal is to identify patients with one or more NIs on the basis of clinical and other data collected during the survey., Methods and Material: Standard surveillance strategies are time-consuming and cannot be applied hospital-wide; alternative methods are required. In NI detection viewed as a classification task, the main difficulty resides in the significant imbalance between positive or infected (11%) and negative (89%) cases. To remedy class imbalance, we explore two distinct avenues: (1) a new re-sampling approach in which both over-sampling of rare positives and under-sampling of the noninfected majority rely on synthetic cases (prototypes) generated via class-specific sub-clustering, and (2) a support vector algorithm in which asymmetrical margins are tuned to improve recognition of rare positive cases., Results and Conclusion: Experiments have shown both approaches to be effective for the NI detection problem. Our novel re-sampling strategies perform remarkably better than classical random re-sampling. However, they are outperformed by asymmetrical soft margin support vector machines which attained a sensitivity rate of 92%, significantly better than the highest sensitivity (87%) obtained via prototype-based re-sampling.

From January to February 2005, the healthcare authorities of the Canton of Geneva were alerted to 15 cases of measles, in contrast to one single case in 2004. The adult status (17-44 years) of the affected persons years was unusual. Four were health care workers at the same hospital who were infected after contact with a 44-year-old patient in a single night during his stay in the emergency room. The presumption that measles are only a paediatric disease had made the diagnosis difficult. None of all these adults was immune according to the actual recommendations. Despite a federal vaccine policy, repetition of recommendations, good results of available vaccines and reimbursement of the cost by health insurance companies, voluntary vaccination prevalence is too small in Switzerland to prevent the outbreak of epidemics. In contrast to the goals of the World Health Organization (WHO) and the Swiss Federal Office of Public Health, the country is unfortunately far from displaying a sufficiently high herd immunity to prevent health care-associated and economic damage by sporadic epidemics.

Objectives: To describe the epidemiology of nosocomial coagulase-negative staphylococci (CoNS) bacteremia and to evaluate the clinical significance of a single blood culture positive for CoNS., Design: A 3-year retrospective cohort study based on data prospectively collected through hospital-wide surveillance. Bacteremia was defined according to CDC criteria, except that a single blood culture growing CoNS was not systematically considered as a contaminant. All clinically significant blood cultures positive for CoNS nosocomial bacteremia were considered for analysis., Setting: A large university teaching hospital in Geneva, Switzerland., Results: A total of 2,660 positive blood cultures were identified. Of these, 1,108 (41.7%) were nosocomial; CoNS were recovered from 411 nosocomial episodes (37.1%). Two hundred thirty-four episodes of CoNS bacteremia in the presence of signs of sepsis were considered clinically relevant and analyzed. Crude mortality and associated mortality were 24.4% and 12.8%, respectively. Associated mortality was similar among patients with one positive blood culture and those with two or more (16.2% vs 10.8%, respectively; P = .3). Mortality rates after bacteremia for patients with a single positive blood culture and for those with two or more were 15.3% and 7.0%, respectively, at day 14 (RR, 2.2; CI95, 0.87-5.46) and 20.8% and 11.3%, respectively, at day 28 (RR, 1.9; CI95, 0.9-3.8). On multivariate analysis, only age and a rapidly fatal disease were independently associated with death., Conclusion: CoNS bacteremia harbor a significant mortality and a single positive blood culture in the presence of signs of sepsis should be considered as clinically relevant.

Objective: To assess the effect of ventilator-associated pneumonia on resource utilization, morbidity, and mortality., Design: Retrospective matched cohort study based on prospectively collected data., Setting: Medical intensive care unit of a university teaching hospital., Patients: Case-patients were all patients receiving mechanical ventilation for 48 hours or more who experienced an episode of ventilator-associated pneumonia. Control-patients were matched for number of discharge diagnoses, duration of mechanical support before the onset of pneumonia among case-patients, age, admission diagnosis, gender, and study period., Results: One hundred six cases of ventilator-associated pneumonia were identified in 452 patients receiving mechanical ventilation. The matching procedure selected 97 pairs. Length of stay in the intensive care unit and duration of mechanical ventilation were greater among case-patients by a mean of 7.2 days (P< .001) and 5.1 days (P< .001), respectively. Median costs were $24,727 (interquartile range, $18,348 to $39,703) among case-patients and $17,438 (interquartile range, $12,261 to $24,226) among control-patients (P < .001). The attributable mortality rate was 7.3% (P = .26). The attributable extra hospital stay was 10 days with an extra cost of $15,986 per episode of pneumonia., Conclusion: Ventilator-associated pneumonia negatively affects patient outcome and represents a significant burden on intensive care unit and hospital resources.

Purpose of Review: There is growing concern that changes in nurse workforce and hospital-restructuring interventions negatively impact on patient outcomes. This review focuses on the association between understaffing and health-care-associated infections., Recent Findings: There is a large number of studies showing that overcrowding, understaffing or a misbalance between workload and resources are important determinants of nosocomial infections and cross-transmission of microorganisms. Importantly, not only the number of staff but also the level of their training affects outcomes. The nurse workforce is ageing, mainly due to fewer individuals' engaging in a nursing career. This phenomenon, combined with cost-driven downsizing, contributes to a nursing shortage, and this tendency is not expected to revert unless important system changes are implemented. The causal pathway between understaffing and infection is complex, and factors might include lack of time to comply with infection control recommendations, job dissatisfaction, job-related burnout, absenteeism and a high staff turnover., Summary: The evidence that cost-driven downsizing and changes in staffing patterns causes harm to patients cannot be ignored, and should not be considered as an inevitable outcome. More research is needed to better define the optimal patient-to-nurse ratio in various hospital settings and to estimate the economical impact of the nursing shortage. All quality-improvement interventions should carefully take into account systems and processes to be successful, as the issue of staffing is essentially a structural problem.

We evaluated the costs associated with a sustained and successful campaign for hand hygiene promotion that emphasized alcohol-based handrubs. The total cost of the hand hygiene promotion corresponded to less than 1% of the costs associated with nosocomial infections. Successful hand hygiene promotion is probably cost-saving.

Primary bloodstream infection (BSI) is a leading, preventable infectious complication in critically ill patients and has a negative impact on patients' outcome. Surveillance definitions for primary BSI distinguish those that are microbiologically documented from those that are not. The latter is known as clinical sepsis, but information on its epidemiologic importance is limited. We analyzed prospective on-site surveillance data of nosocomial infections in a medical intensive care unit. Of the 113 episodes of primary BSI, 33 (29%) were microbiologically documented. The overall BSI infection rate was 19.8 episodes per 1,000 central-line days (confidence interval [CI] 95%, 16.1 to 23.6); the rate fell to 5.8 (CI 3.8 to 7.8) when only microbiologically documented episodes were considered. Exposure to vascular devices was similar in patients with clinical sepsis and patients with microbiologically documented BSI. We conclude that laboratory-based surveillance alone will underestimate the incidence of primary BSI and thus jeopardize benchmarking.

Nosocomial infections (NIs)---those acquired in health care settings---are among the major causes of increased mortality among hospitalized patients. They are a significant burden for patients and health authorities alike; it is thus important to monitor and detect them through an effective surveillance system. This paper describes a retrospective analysis of a prevalence survey of NIs done in the Geneva University Hospital. Our goal is to identify patients with one or more NIs on the basis of clinical and other data collected during the survey. In this two-class classification task, the main difficulty lies in the significant imbalance between positive or infected (11%) and negative (89%) cases. To cope with class imbalance, we investigate one-class SVMs which can be trained to distinguish two classes on the basis of examples from a single class (in this case, only "normal" or non infected patients). The infected ones are then identified as "abnormal" cases or outliers that deviate significantly from the normal profile. Experimental results are encouraging: whereas standard 2-class SVMs scored a baseline sensitivity of 50.6% on this problem, the one-class approach increased sensitivity to as much as 92.6%. These results are comparable to those obtained by the authors in a previous study on asymmetrical soft margin SVMs; they suggest that one-class SVMs can provide an effective and efficient way of overcoming data imbalance in classification problems.

Objective: To determine the influence of using different denominators on risk estimates of ventilator-associated pneumonia (VAP)., Design and Setting: Prospective cohort study in the medical ICU of a large teaching hospital., Patients: All consecutive patients admitted for more than 48 h between October 1995 and November 1997., Measurements and Results: We recorded all ICU-acquired infections using modified CDC criteria. VAP rates were reported per 1,000 patient-days, patient-days at risk, ventilator-days, and ventilator-days at risk. Of the 1,068 patients admitted, VAP developed in 106 (23.5%) of those mechanically ventilated. The incidence of the first episode of VAP was 22.8 per 1,000 patient-days (95% CI 18.7-27.6), 29.6 per 1,000 patient-days at risk (24.2-35.8), 35.7 per 1,000 ventilator-days (29.2-43.2), and 44.0 per 1,000 ventilator-days at risk (36.0-53.2). When considering all episodes of VAP (n=127), infection rates were 27.3 episodes per 1,000 ICU patient-days (95% CI 22.6-32.1) and 42.8 episodes per 1,000 ventilator-days (35.3-50.2)., Conclusions: The method of reporting VAP rates has a significant impact on risk estimates. Accordingly, clinicians and hospital management in charge of patient-care policies should be aware of how to read and compare nosocomial infection rates.

Objective: To assess the added value of surveying patients after discharge from the intensive care unit., Design: Prospective cohort study., Setting: Medical intensive care unit of a large teaching hospital., Patients: All patients admitted to the intensive care unit for 48 hrs or more from October 1995 to November 1997., Measurements and Main Results: We prospectively surveyed 1,068 patients during their intensive care unit stay and for 5 days after intensive care unit discharge. We detected 554 intensive care unit-acquired infections, yielding an infection rate of 70.7 per 1,000 patient days. Of these, only 31 infections (5.6%) in 27 patients were detected after intensive care unit discharge. If postdischarge surveillance was targeted on patients who had had a central vascular catheter while in the intensive care unit, only one infected patient would have been missed, but only 554 out of 889 would have been followed up (sensitivity, 96.2%; specificity, 38.7%; negative predictive value, 99.7%)., Conclusions: Surveillance of all patients discharged from the medical intensive care unit is not recommended, as it is resource demanding and allows the detection of few additional infections. However, targeted postdischarge surveillance could be a rational alternative, and selection criteria need to be refined and validated.

Hypothesis: A set of clinical variables available at the bedside can be used to predict outcome in critically ill patients with bloodstream infection (BSI)., Design: A 3-year retrospective cohort study., Setting: A surgical intensive care unit in Switzerland., Patients: All patients with BSI were potentially eligible., Main Outcome Measures: Clinical variables, organ dysfunctions, and outcome., Results: Among 4530 admissions to the surgical intensive care unit, 224 clinically significant episodes of BSI were recorded (incidence, 4.9%), with a 28-day fatality of 36%. A total of 110 patients had primary bacteremia, of which 39 (35%) were catheter related. Although gram-positive organisms were the most frequently isolated pathogens (58% [159/275]), they were associated with lower case-fatality (30%) than BSI due to gram-negative bacteria (44%). Organ dysfunctions associated with the highest risk of death were neurologic dysfunction (hazard ratio [HR], 6.9; 95% confidence interval [CI], 3.3-14.5), hepatic dysfunction (HR, 3.9; 95% CI, 2.1-7.4), and disseminated intravascular coagulation (HR, 3.0; 95% CI, 1.5-6.1). By multivariate analysis, 2 independent predictors of mortality were the APACHE II (Acute Physiology and Chronic Health Evaluation II) score at onset of BSI (HR per 1-point increase, 1.08; 95% CI, 1.04-1.12) and the number of evolving organ dysfunctions (HR, 1.4; 95% CI, 1.2-1.7). Appropriate antimicrobial therapy was associated with improved outcome (HR, 0.4; 95% CI, 0.2-0.6)., Conclusions: Bloodstream infection in critically ill patients is a common and frequently fatal condition. Its outcome can be predicted by the severity of illness at onset of BSI and the number of organ dysfunctions evolving thereafter. Appropriate antimicrobial therapy is an important determinant for survival.

Background: Nosocomial infection is a leading complication in intensive care units. Although hand hygiene is the single most efficient preventive measure, compliance with this simple action remains low., Objectives: To assess the effect of an intervention to promote hand hygiene and to investigate risk factors for noncompliance in intensive care units., Methods: We performed 7 observational surveys and implemented a promotional campaign after baseline in medical, surgical, and pediatric intensive care units of a teaching hospital. Health care workers were observed during routine patient care. The intervention consisted of a hospitalwide promotional campaign, including observation and performance feedback, posters display, and distribution of individual bottles of alcohol-based handrub. The main outcome measure was compliance with hand hygiene through handwashing or handrubbing., Results: We observed 2743 opportunities for hand hygiene distributed over 248 periods. Overall compliance increased from 38.4% to 54.5% during the study (P<.001). Although recourse to handwashing remained stable at around 30%, handrubbing increased from 5.4% at baseline to 21.7% at the last survey (P<.001). Compliance increased among nurses and nursing assistants, but remained stable among physicians. Handwashing compliance decreased, on average, by 4.7% for an increase of 10 opportunities for hand hygiene per hour of patient care (P<.001), whereas no such association existed for handrubbing., Conclusions: Our intervention induced a marked and sustained increase in compliance with hand hygiene. In intensive care units, less time-consuming handrubbing might replace standard handwashing and overcome the barrier of time constraints.

A study was performed to estimate the prevalence of nosocomial infections (NI) and assess differences between medical care settings in one hospital complex. A seven-day period-prevalence survey was conducted in May 1998 in a large primary and tertiary healthcare centre in Geneva, Switzerland, that included all patients in acute, sub-acute and chronic care settings. Variables included demography, exposure to invasive devices and antibiotics, surgical history, and patients' localization. Overall prevalence of NI was 11.3% (acute, 8.4%; sub-acute, 11.4%; chronic care setting, 16.4%) in the 1928 patients studied, and ranged from 0% in ophthalmology to 23% in critical care units. Odds of infection in sub-acute and chronic care settings were significantly higher than in the acute care setting even after adjustment for case-mix [OR, 2.59; 95% confidence interval (CI(95)) 1.53-4.41; and OR, 2.34; Cl(95)1.38-3.95, respectively]. As a distinct group, patients in the geriatric location (belonging to the sub-acute care setting) showed a significant proportion of urinary (39%) and respiratory (21%) tract infections, contrasting with a relatively low exposure to urinary catheters (6.1%) and orotracheal intubation (0%). In conclusion, sub-acute and chronic care settings are associated with high infection prevalence even after case-mix adjustment. Prevalence studies are an easy surveillance tool that can be exploited further by analysing data according to hospital care settings to identify high-risk areas., (Copyright 2001 The Hospital Infection Society.)

Background: Hand hygiene prevents cross infection in hospitals, but compliance with recommended instructions is commonly poor. We attempted to promote hand hygiene by implementing a hospital-wide programme, with special emphasis on bedside, alcohol-based hand disinfection. We measured nosocomial infections in parallel., Methods: We monitored the overall compliance with hand hygiene during routine patient care in a teaching hospital in Geneva, Switzerland, before and during implementation of a hand-hygiene campaign. Seven hospital-wide observational surveys were done twice yearly from December, 1994, to December, 1997. Secondary outcome measures were nosocomial infection rates, attack rates of methicillin-resistant Staphylococcus aureus (MRSA), and consumption of handrub disinfectant., Findings: We observed more than 20,000 opportunities for hand hygiene. Compliance improved progressively from 48% in 1994, to 66% in 1997 (p<0.001). Although recourse to handwashing with soap and water remained stable, frequency of hand disinfection substantially increased during the study period (p<0.001). This result was unchanged after adjustment for known risk factors of poor adherence. Hand hygiene improved significantly among nurses and nursing assistants, but remained poor among doctors. During the same period, overall nosocomial infection decreased (prevalence of 16.9% in 1994 to 9.9% in 1998; p=0.04), MRSA transmission rates decreased (2.16 to 0.93 episodes per 10,000 patient-days; p<0.001), and the consumption of alcohol-based handrub solution increased from 3.5 to 15.4 L per 1000 patient-days between 1993 and 1998 (p<0.001)., Interpretation: The campaign produced a sustained improvement in compliance with hand hygiene, coinciding with a reduction of nosocomial infections and MRSA transmission. The promotion of bedside, antiseptic handrubs largely contributed to the increase in compliance.

Over a century has passed since Ignaz P. Semmelweis demonstrated the association between hand hygiene and nosocomial infections, but this simple procedure is still not recognized by many healthcare workers as one of the most important measures to prevent cross-transmission of microorganisms. A relatively large amount of research has been done, in particular to try to understand why compliance remains so low, in order to implement successful promotion campaigns. This research has generated a fair amount of strong scientific data which are sometimes misunderstood and misused because of myths or certain beliefs. Observational or intervention studies have consistently shown a number of risk factors associated with non-compliance, such as high workload, professional category, or type of ward. Others are thought to be barriers to adequate compliance but have not yet been properly assessed. These include skin irritation due to hand hygiene agents, lack of knowledge of hand hygiene recommendations, or lack of institutional policy. Future interventions to promote hand hygiene will need to address these risk factors, and target the individual healthcare worker, as well as the group or institution if a significant degree of success is to be achieved.