Costs and possible benefits of a two-tier infection control management strategy consisting of active screening for multidrug-resistant organisms and tailored control measures

Development and validation of machine learning models to predict MDRO colonization or infection on ICU admission by using electronic health record data

BACKGROUND

Multidrug-resistant organisms (MDRO) pose a significant threat to public health. Intensive Care Units (ICU), characterized by the extensive use of antimicrobial agents and a high prevalence of bacterial resistance, are hotspots for MDRO proliferation. Timely identification of patients at high risk for MDRO can aid in curbing transmission, enhancing patient outcomes, and maintaining the cleanliness of the ICU environment. This study focused on developing a machine learning (ML) model to identify patients at risk of MDRO during the initial phase of their ICU stay.

METHODS

Utilizing patient data from the First Medical Center of the People's Liberation Army General Hospital (PLAGH-ICU) and the Medical Information Mart for Intensive Care (MIMIC-IV), the study analyzed variables within 24 h of ICU admission. Machine learning algorithms were applied to these datasets, emphasizing the early detection of MDRO colonization or infection. Model efficacy was evaluated by the area under the receiver operating characteristics curve (AUROC), alongside internal and external validation sets.

RESULTS

The study evaluated 3,536 patients in PLAGH-ICU and 34,923 in MIMIC-IV, revealing MDRO prevalence of 11.96% and 8.81%, respectively. Significant differences in ICU and hospital stays, along with mortality rates, were observed between MDRO positive and negative patients. In the temporal validation, the PLAGH-ICU model achieved an AUROC of 0.786 [0.748, 0.825], while the MIMIC-IV model reached 0.744 [0.723, 0.766]. External validation demonstrated reduced model performance across different datasets. Key predictors included biochemical markers and the duration of pre-ICU hospital stay.

CONCLUSIONS

The ML models developed in this study demonstrated their capability in early identification of MDRO risks in ICU patients. Continuous refinement and validation in varied clinical contexts remain essential for future applications.

Outcome of Candida auris contact investigations conducted in a 6 month period at a New York City hospital

Candida auris is a multidrug-resistant fungus that has led to health care-associated outbreaks globally. Contact investigations for new cases of Candida auris are a recommended infection prevention practice; however, there is limited knowledge and experience with such investigations. We describe our institution's experience from June 2018 through January 2019.

Quantification of time delay between screening and subsequent initiation of contact isolation for carriers of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales: A post hoc subgroup analysis of the R-GNOSIS WP5 Trial

OBJECTIVES

The aim of this study was to quantify the time delay between screening and initiation of contact isolation for carriers of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-E).

METHODS

This study was a secondary analysis of contact isolation periods in a cluster-randomized controlled trial that compared 2 strategies to control ESBL-E (trial no. ISRCTN57648070). Patients admitted to 20 non-ICU wards in Germany, the Netherlands, Spain, and Switzerland were screened for ESBL-E carriage on admission, weekly thereafter, and on discharge. Data collection included the day of sampling, the day the wards were notified of the result, and subsequent ESBL-E isolation days.

RESULTS

Between January 2014 and August 2016, 19,122 patients, with a length of stay ≥2 days were included. At least 1 culture was collected for 16,091 patients (84%), with a median duration between the admission day and the day of first sample collection of 2 days (interquartile range [IQR], 1-3). Moreover, 854 (41%) of all 2,078 ESBL-E carriers remained without isolation during their hospital stay. In total, 6,040 ESBL-E days (32% of all ESBL-E days) accrued for patients who were not isolated. Of 2,078 ESBL-E-carriers, 1,478 ESBL-E carriers (71%) had no previous history of ESBL-E carriage. Also, 697 (34%) were placed in contact isolation with a delay of 4 days (IQR, 2-5), accounting for 2,723 nonisolation days (15% of ESBL-E days).

CONCLUSIONS

Even with extensive surveillance screening, almost one-third of all ESBL-E days were nonisolation days. Limitations in routine culture-based ESBL-E detection impeded timely and exhaustive implementation of targeted contact isolation.

Screening for Intestinal Carriage of Extended-spectrum Beta-lactamase-producing Enterobacteriaceae in Critically Ill Patients: Expected Benefits and Evidence-based Controversies

The rising burden of intensive care unit (ICU)-acquired infections due to extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) strengthens the requirement for efficient prevention strategies. The detection of intestinal carriage of ESBL-E through active surveillance cultures (ASC) and the implementation of contact precautions (CP) in carriers are currently advocated in most high-income countries, to prevent cross-transmission and subsequent ESBL-E infections in critically-ill patients. Yet, recent studies have challenged the benefit of ASC and CP in controlling the spread of ESBL-E in ICUs with high compliance to standard hygiene precautions and no ongoing outbreak of ESBL-producing Klebsiella pneumoniae or Enterobacter spp. Besides, given their debated performance to positively predict which patients are at risk of ESBL-E infections, ASC results appear of limited value to rationalize the empirical use of carbapenems in the ICU, emphasizing the urgent need for novel anticipatory and diagnostic approaches. This Viewpoint article summarizes the available evidence on these issues.

In-hospital costs of community-acquired colonization with multidrug-resistant organisms at a German teaching hospital

Background

Antibiotic resistance is a challenge in the management of infectious diseases and can cause substantial cost. Even without the onset of infection, measures must be taken, as patients colonized with multi-drug resistant (MDR) pathogens may transmit the pathogen. We aim to quantify the cost of community-acquired MDR colonizations using routine data from a German teaching hospital.

Methods

All 2006 cases of documented MDR colonization at hospital admission recorded from 2011 to 2014 are matched to 7917 unexposed controls with the same primary diagnosis. Cases with an onset MDR infection are excluded from the analysis. Routine data on costs per case is analysed for three groups of MDR bacteria: Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus (VRE), and multidrug-resistant gram-negative bacteria (MDR-GN). Multivariate analyses are conducted to adjust for potential confounders.

Results

After controlling for main diagnosis group, age, sex, and Charlson Comorbidity Index, MDR colonization is associated with substantial additional costs from the healthcare perspective (€1480.9, 95%CI €1286.4–€1675.5). Heterogeneity between pathogens remains. Colonization with MDR-GN leads to the largest cost increase (€1966.0, 95%CI €1634.6–€2297.4), followed by MRSA with €1651.3 (95%CI €1279.1–€2023.6), and VRE with €879.2 (95%CI €604.1–€1154.2). At the same time, MDR-GN is associated with additional reimbursements of €887.8 (95%CI €722.1–€1053.6), i.e. costs associated with MDR-colonization exceed reimbursement.

Conclusions

Even without the onset of invasive infection, documented MDR-colonization at hospital admission is associated with increased hospital costs, which are not fully covered within the German DRG-based hospital payment system.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3549-0) contains supplementary material, which is available to authorized users.

Carbapenem-resistant Gram-negative pathogens in a German university medical center: Prevalence, clinical implications and the role of novel β-lactam/β-lactamase inhibitor combinations

Objectives

To determine the spectrum of infections with multidrug-resistant Gram-negative bacteria (MDR-GNB) and the clinical impact of the newly available betalactam/betalactamase inhibitor combinations ceftolozane/tazobactam and ceftazidime/avibactam in a German academic tertiary care center.

Methods

Retrospective analysis.

Results

Between September 1, 2015 and August 31, 2016, 119 individual patients (0.22% of all hospital admissions) were colonized or infected with carbapenem-resistant MDR-GNB. The species distribution was Pseudomonas aeruginosa, n = 66; Enterobacteriaceae spp., n = 44; and Acinetobacter baumannii, n = 18. In 9 patients, carbapenem-resistant isolates belonging to more than one species were detected. Infection was diagnosed in 50 patients (total: 42.0%; nosocomial pneumonia: n = 23, 19.3%; bloodstream infection: n = 11, 9.2%). Antimicrobial treatment with broad-spectrum antibiotics prior to detection of a carbapenem-resistant isolate was documented in 105 patients (88.2%, prior administration of carbapenems: 62.2%). Nosocomial transmission was documented in 29 patients (24.4%). In 26 patients (21.8%), at least one carbapenem-susceptible, third-generation cephalosporin non-susceptible isolate was documented prior to detection of a carbapenem-resistant isolate belonging to the same species (median 38 days, IQR 23–78). 12 patients (10.1%) had documented previous contact to the healthcare system in a country with high burden of carbapenemase-producing strains. Genes encoding carbapenemases were detected in 60/102 patient isolates (58.8%; VIM-2, n = 25; OXA-48, n = 21; OXA-23-like, n = 10). Susceptibility to colistin was 94.3%. Ceftolozane/tazobactam and ceftazidime/avibactam were administered to 3 and 5 patients, respectively (in-hospital mortality: 66% and 100%). Development of drug-resistance under therapy was observed for both antimicrobials.

Conclusions

i) The major predisposing factors for acquisition of carbapenem-resistant MDR-GNB were selective pressure due to preceding antimicrobial therapy and nosocomial transmission. ii) Colistin remains the backbone of antimicrobial chemotherapy for infections caused by carbapenem-resistant MDR-GNB. iii) Novel β-lactam/β-lactamase inhibitor combinations are of limited usefulness in our setting because of the high prevalence of Ambler class B carbapenemases and the emergence of nonsusceptibility under therapy.

Effect of multiple drug resistance on total medical costs among patients with intra-abdominal infections in China

Background

Multiple drug resistant (MDR) intra-abdominal infections (IAIs) are associated with notable direct and societal costs. As previous studies have not considered the impact of MDR on the total medical costs (TMCs) of IAIs, the present one examines this, as well as further estimates the additional costs at a national level.

Methods

This is a retrospective study. Firstly, we randomly selected a sample of 40% of all inpatients discharged between 2014 and 2015 from a teaching hospital, due to limits in budget and the large number of patients. Then, we manually selected 254 patients with IAIs according to the International Classification of Disease, 10^th revision, using electronic medical records. Eventually, 101 patients with IAIs (64 MDR patients and 37 non-MDR patients) were included after excluding cases without laboratory test results, any pathogens detected, or antimicrobial resistant pathogens. Univariate analysis and a generalized linear model were applied to assess the parameters associated with TMCs.

Results

Compared to non-MDR patients, those with MDR pathogens were significantly associated with higher TMCs, higher antimicrobial costs, higher antimicrobial usage, larger number of pathogens, and longer length of stay and were more likely to have insurance and combination antimicrobial therapy. In addition, the average TMC among patients with MDR pathogens was ¥ 131801, which is ¥ 90201 higher than those without MDR pathogens. If our results are applied to the whole country, the sum of all attributable TMCs was ¥ 37 billion. The societal costs, furthermore, were ¥111 billion in 2015.

Conclusion

Our results provide information that should lead to increased efforts to reduce inappropriate antimicrobial therapy, in order to decrease the emergence of MDR pathogens and to reduce their economic burden.

Infection control interventions affected by resource shortages: impact on the incidence of bacteremias caused by carbapenem-resistant pathogens

We evaluated an infection control (IC) program influenced by personnel and material resource shortages on the incidence of bloodstream infections (BSI) due to carbapenem-resistant Klebsiella pneumoniae (CRKP), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPA) in an endemic region. Between January 2010 and December 2015, all BSI episodes caused by CRKP, CRAB, and CRPA were recorded. An IC bundle was implemented in January 2012. We evaluated the effect of the interventions on BSI rates between the pre-intervention (2010-2011) and intervention (2012-2013) periods, using an interrupted time-series model. From 2014, when interventions were still applied, BSI incidence was gradually increased. For this reason, we evaluated with a linear mixed effects model several factors possibly contributing to this increase for the years 2012-2015, which was considered as the intervention/follow-up period. During the study period, 351 patients with BSI were recorded, with a total of 538 episodes; the majority (83.6%) occurred in the intensive care unit (ICU). The BSI incidence rate per year during 2010-2015 for ICU patients was 21.03/19.63/17.32/14.45/22.85/25.02 per 1000 patient-days, respectively, with the reduction in BSI levels after the start of intervention marginal (p = 0.054). During the follow-up period (2014-2015), the most influential factors for the increased BSI incidence were the reduced participation in educational courses and compliance with hand hygiene. The implementation of IC interventions reduced the BSI incidence rates, particularly for ICU patients. However, factors possibly related to the restrictions of human and material resources apparently contributed to the observed expansion of BSI in our endemic setting.

Development and evaluation of the automated risk assessment system for multidrug-resistant organisms (autoRAS-MDRO)

BACKGROUND

A high proportion of infections acquired in hospitals are caused by multidrug-resistant organisms (MDROs). The priority in MDRO prevention is to detect high-risk patients and implement preventive intervention as soon as possible.

AIM

To develop an automated risk assessment system for MDROs (autoRAS-MDRO) to screen for patients at MDRO infection risk and evaluate the predictive validity of the autoRAS-MDRO.

METHODS

Data for 4200 variables were extracted from the electronic health records (EHRs) for constructing the MDRO risk-scoring algorithm, which was based on a logistic regression model. The autoRAS-MDRO was designed such that the MDRO risk classification (high, moderate, low risk) could be automatically displayed on the nursing Kardex screen in the EHRs system. For the development of the MDRO risk-scoring algorithm, 1000 patients with MDROs and 4000 patients without MDROs were selected; similarly, for the evaluation, 2173 and 8692 patients with and without MDROs, respectively, were selected.

FINDINGS

The predictive validity of the autoRAS-MDRO was as follows: (i) at the 6-month evaluation: sensitivity, 81%; specificity, 79%; positive predictive value (PPV), 49%; negative predictive value (NPV), 94%; and Youden index, 0.60; (ii) at the 12-month evaluation: sensitivity 79%, specificity 78%, PPV 47%, NPV 94%, and Youden index, 0.57.

CONCLUSION

The autoRAS-MDRO had moderate predictive validity. It could be useful in redirecting nurses' time and efforts required for MDRO risk assessment and implementation of infection control measures, and in reducing the incidence of MDRO infection in hospitals, thereby contributing to patient safety.

The relationship between subjective perception and the psychological effects of patients in spatial isolation

Background: Spatial isolation is a common infection control measure, but negative psychological effects are often neglected. We investigated which factors influence the perception of single room isolated patients.

Methods: In the present correlative cross-sectional study, 32 isolated patients have been interviewed within three departments of the Heidelberg University Hospital, one of Germany’s largest hospitals. The following questionnaires were used: 10-Item Big Five Inventory (BFI-10), Positive and Negative Affect Schedule (PANAS), Hospital Anxiety and Depression Scale (HADS) and a self-developed questionnaire to evaluate the individual experience of isolation. Data were analysed using correlation and regression analysis.

Results: A significant positive correlation was found between the isolation period and anxiety (r=.42, p<.05). Interestingly, a significant positive correlation was demonstrated between the duration of contact to nursing staff and negative daydreaming (r=.89, p<.01). The activity watching television was associated with higher levels of anxiety (r=.38, p<.05). Surfing the internet had a positive relationship with thinking about beautiful things (r=.41, p<.05).

Conclusions: Our study results have implications how to improve the psychological situation of patients during spatial isolation. Contact between nursing staff and patients is crucial, since this contact significantly associated with negative daydreaming, probably due to increased neediness of emotional and physical care in some patients. The duration of the isolation has an influence on the experience of anxiety. Activities to cope with the isolation, however, not always have positive effects on the well-being of the patient.

High burden of Carbapenem-resistant Enterobacteriaceae (CRE) fecal carriage at a teaching hospital: cost-effectiveness of screening in low-resource setting

Background

Infections by multidrug-resistant gram-negative bacteria (MDR-GNB) have been continuously growing and pose challenge to health institution globally. Carbapenem-resistant Enterobacteriacea (CRE) was identified as one of the MDR-GNB which has limited treatment options and higher mortality compared to those of sensitive strains. We report an increased burden of CRE fecal carriage at a hospital in the North-eastern region of Malaysia.

Methods

A retrospective descriptive study from August 2013 to December 2015 was conducted in the Medical Microbiology & Parasitology laboratory of Hospital Universiti Sains Malaysia, which is a tertiary teaching hospital with more than 700 beds. This hospital treats patients with various medical and surgical conditions. Suspected CRE from any clinical specimens received by the laboratory was identified and confirmed using standard protocols. Polymerase chain reaction (PCR) assay was performed to determine the genotype.

Results

Altogether, 8306 Enterobacteriaceae was isolated from various clinical specimens during the study period and 477/8306 (5.74%) were CRE. Majority of the isolated CRE were Klebsiella [408/477, (85.5%)], of which Klebsiella pneumoniae was the predominant species, 388/408 (95%). CRE were mainly isolated from rectal swab (screening), 235/477 (49.3%); urine, 76/477 (15.9%); blood, 46/477 (9.6%) and about 7.1% from tracheal aspirate. One hundred and thirty-six isolates were subjected to genotype determination and., 112/136 (82.4%) showed positive detection of New Delhi metallo-β-lactamase 1 (NDM-1) gene (bla_NDM1).

Conclusion

The study noted a high numbers of CRE isolated especially from rectal swabs. Active screening results in significant cost pressures and therefore should be revisited and revised, especially in low resource settings.

Environmental audits and process flow mapping to assess management of solid waste and wastewater from a healthcare facility: an Italian case study

In Europe, there are an increasing number of policy and legislative drivers for a more sustainable approach to the management of natural resources as well as for the mitigation of environmental health risks. However, despite significant progress in recent years, there is still some way to go to achieve circularity of process, as well as risk mitigation within organisations. Using a case study of the Gardone Val Trompia hospital in northern Italy, this manuscript offers a novel holistic examination of strategies to enhance resource efficiency and environmental health within a key sector, i.e. the healthcare sector. Through the use of environmental audits and process flow mapping, trends in waste and wastewater arisings and the associated financial and environmental costs and risks were identified. Recommendations for developing more resource efficient approaches as well as mitigating the environmental and public health risks are suggested. These include strategies for improved resource efficiency (including reduction in the hazardous waste) and reduced environmental impacts during the containment, transport and treatment of the waste.

Counting the cost of an outbreak of carbapenemase-producing Enterobacteriaceae: an economic evaluation from a hospital perspective

OBJECTIVE

To perform an economic evaluation on the cost associated with an outbreak of carbapenemase-producing Enterobacteriaceae (CPE).

METHODS

We performed an observational economic evaluation of an outbreak of CPE (NDM-producing Klebsiella pneumoniae) affecting 40 patients in a group of five hospitals across three sites in West London. Costs were split into actual expenditure (including anti-infective costs, enhanced CPE screening, contact precautions, temporary ward-based monitors of hand and environmental practice, and environmental decontamination), and 'opportunity cost' (staff time, bed closures and elective surgical missed revenue). Costs are estimated from the hospital perspective over the 10-month duration of the outbreak.

RESULTS

The outbreak cost €1.1m over 10 months (range €0.9-1.4m), comprising €312 000 actual expenditure, and €822 000 (range €631 000-€1.1m) in opportunity cost. An additional €153 000 was spent on Estates renovations prompted by the outbreak. Actual expenditure comprised: €54 000 on anti-infectives for 18 patients treated, €94 000 on laboratory costs for screening, €73 000 on contact precautions for 1831 contact precautions patient-days, €42 000 for hydrogen peroxide vapour decontamination of 24 single rooms, €43 000 on 2592 hours of ward-based monitors, and €6000 of expenditure related to ward and bay closures. Opportunity costs comprised: €244 000 related to 1206 lost bed-days (range 366-2562 bed-days, €77 000-€512 000), €349 000 in missed revenue from 72 elective surgical procedures, and €228 000 in staff time (range €205 000-€251 000). Reduced capacity to perform elective surgical procedures related to bed closures (€349 000) represented the greatest cost.

CONCLUSIONS

The cost estimates that we present suggest that CPE outbreaks are highly costly.