The Impact of Reducing Antibiotics on the Transmission of Multidrug-Resistant Organisms

Using contact network dynamics to implement efficient interventions against pathogen spread in hospital settings: A modelling study

BACKGROUND

Long-term care facilities (LTCFs) are hotspots for pathogen transmission. Infection control interventions are essential, but the high density and heterogeneity of interindividual contacts within LTCF may hinder their efficacy. Here, we explore how the patient-staff contact structure may inform effective intervention implementation.

METHODS AND FINDINGS

Using an individual-based model (IBM), we reproduced methicillin-resistant Staphylococcus aureus colonisation transmission dynamics over a detailed contact network recorded within a French LTCF of 327 patients and 263 staff over 3 months. Simulated baseline cumulative colonisation incidence was 21 patients (prediction interval: 11, 31) and 35 staff (prediction interval: 19, 54). We examined the potential impact of 3 types of interventions against transmission (reallocation reducing the number of unique contacts per staff, reinforced contact precautions, and hypothetical vaccination protecting against acquisition), targeted towards specific populations. All 3 interventions were effective when applied to all nurses or healthcare assistants (median reduction in MRSA colonisation incidence up to 35%), but the benefit did not exceed 8% when targeting any other single staff category. We identified "supercontactor" individuals with most contacts ("frequency-based," overrepresented among nurses, porters, and rehabilitation staff) or with the longest cumulative time spent in contact ("duration-based," overrepresented among healthcare assistants and patients in elderly care or persistent vegetative state (PVS)). Targeting supercontactors enhanced interventions against pathogen spread in the LTCF. With contact precautions, targeting frequency-based staff supercontactors led to the highest incidence reduction (20%, 95% CI: 19, 21). Vaccinating a mix of frequency- and duration-based staff supercontactors led to a higher reduction (23%, 95% CI: 22, 24) than all other approaches. Although based on data from a single LTCF, when varying epidemiological parameters to extend to other pathogens, our results suggest that targeting supercontactors is always the most effective strategy, indicating this approach could be applied to prevent transmission of other nosocomial pathogens.

CONCLUSIONS

By characterising the contact structure in hospital settings and identifying the categories of staff and patients more likely to be supercontactors, with either more or longer contacts than others, interventions against nosocomial spread could be more effective. We find that the most efficient implementation strategy depends on the intervention (reallocation, contact precautions, vaccination) and target population (staff, patients, supercontactors). Importantly, both staff and patients may be supercontactors, highlighting the importance of including patients in measures to prevent pathogen transmission in LTCF.

Standardization of Antibiotic Management and Reduction of Opioid Prescribing in Pediatric Complicated Appendicitis: A Quality Improvement Initiative

BACKGROUND

Appendicitis is one of the most common pediatric surgical procedures in the United States. However, wide variation remains in antibiotic prescribing and pain management across and within institutions. We aimed to minimize variation in antibiotic usage and decrease opioid prescribing at discharge for children with complicated appendicitis by implementation of a quality improvement (QI) initiative.

METHODS

On December 1st, 2021, a QI initiative standardizing postoperative care for complicated appendicitis was implemented across a tertiary pediatric healthcare system with two main surgical centers. QI initiative focused on antibiotic and pain management. An extensive literature search was performed and a total of 20 articles matching our patient population were critically appraised to determine the best evidence-based interventions to implement. Antibiotic regimen included: IV or PO ceftriaxone/metronidazole immediately post-operatively and transition to PO amoxicillin-clavulanic acid for completion of 7-day total course at discharge. Discharge pain control regimen included acetaminophen, ibuprofen, as needed gabapentin, and no opioid prescription. Guideline compliance were closely monitored for the first six months following implementation.

RESULTS

In the first 6-months post-implementation, compliance with use of ceftriaxone/metronidazole as initial post-operative antibiotics was 75.6 %. Transition to PO amoxicillin-clavulanic acid prior to discharge increased from 13.7 % pre-implementation to 73.7 % 6-months post-implementation (p < 0.001). Compliance with a 7-day course of antibiotics within the first 6-months post-implementation was 60 % across both sites. After QI intervention, overall opioid prescribing remained at 0 % at one surgical site and decreased from 17.6 % to 0 % at the second surgical site over the study timeframe (p < 0.001).

CONCLUSION

Antibiotic use can be standardized and opioid prescribing minimized in children with complicated appendicitis using QI principles. Continued monitoring of the complicated appendicitis guideline is needed to assess for further progress in the standardization of post-operative care.

STUDY TYPE

Quality improvement.

LEVEL OF EVIDENCE

Level III.

Protocol for a parallel cluster randomized trial of a participatory tailored approach to reduce overuse of antibiotics at hospital discharge: the ROAD home trial

BACKGROUND

Antibiotic overuse at hospital discharge is common, costly, and harmful. While discharge-specific antibiotic stewardship interventions are effective, they are resource-intensive and often infeasible for hospitals with resource constraints. This weakness impacts generalizability of stewardship interventions and has health equity implications as not all patients have access to the benefits of stewardship based on where they receive care. There may be different pathways to improve discharge antibiotic prescribing that vary widely in feasibility. Supporting hospitals in selecting interventions tailored to their context may be an effective approach to feasibly reduce antibiotic overuse at discharge across diverse hospitals. The objective of this study is to evaluate the effectiveness of the Reducing Overuse of Antibiotics at Discharge Home multicomponent implementation strategy ("ROAD Home") on antibiotic overuse at discharge for community-acquired pneumonia and urinary tract infection.

METHODS

This 4-year two-arm parallel cluster-randomized trial will include three phases: baseline (23 months), intervention (12 months), and postintervention (12 months). Forty hospitals recruited from the Michigan Hospital Medicine Safety Consortium will undergo covariate-constrained randomization with half randomized to the ROAD Home implementation strategy and half to a "stewardship as usual" control. ROAD Home is informed by the integrated-Promoting Action on Research Implementation in Health Services Framework and includes (1) a baseline needs assessment to create a tailored suite of potential stewardship interventions, (2) supported decision-making in selecting interventions to implement, and (3) external facilitation following an implementation blueprint. The primary outcome is baseline-adjusted days of antibiotic overuse at discharge. Secondary outcomes include 30-day patient outcomes and antibiotic-associated adverse events. A mixed-methods concurrent process evaluation will identify contextual factors influencing the implementation of tailored interventions, and assess implementation outcomes including acceptability, feasibility, fidelity, and sustainment.

DISCUSSION

Reducing antibiotic overuse at discharge across hospitals with varied resources requires tailoring of interventions. This trial will assess whether a multicomponent implementation strategy that supports hospitals in selecting evidence-based stewardship interventions tailored to local context leads to reduced overuse of antibiotics at discharge. Knowledge gained during this study could inform future efforts to implement stewardship in diverse hospitals and promote equity in access to the benefits of quality improvement initiatives.

TRIAL REGISTRATION

Clinicaltrials.gov NCT06106204 on 10/30/23.

Association of SARS-CoV-2 status and antibiotic-resistant bacteria with inadequate empiric therapy in hospitalized patients: a US multicenter cohort evaluation (July 2019 - October 2021)

BACKGROUND

Antibiotic usage and antibiotic resistance (ABR) patterns changed during the COVID-19 pandemic. Inadequate empiric antibiotic therapy (IET) is a significant public health problem and contributes to ABR. We evaluated factors associated with IET before and during the COVID-19 pandemic to determine the impact of the pandemic on antibiotic management.

METHODS

This multicenter, retrospective cohort analysis included hospitalized US adults who had a positive bacterial culture (specified gram-positive or gram-negative bacteria) from July 2019 to October 2021 in the BD Insights Research Database. IET was defined as antibacterial therapy within 48 h that was not active against the bacteria. ABR results were based on susceptibility testing and reports from local facilities. Multivariate analysis was used to identify risk factors associated with IET in patients with any positive bacterial culture and ABR-positive cultures, including multidrug-resistant (MDR) bacteria.

RESULTS

Of 278,344 eligible patients in 269 hospitals, 56,733 (20.4%) received IET; rates were higher in patients with ABR-positive (n = 93,252) or MDR-positive (n = 39,000) cultures (34.9% and 45.0%, respectively). Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2)-positive patients had significantly higher rates of IET (25.9%) compared with SARS-CoV-2-negative (20.3%) or not tested (19.7%) patients overall and in the ABR and MDR subgroups. Patients with ABR- or MDR-positive cultures had more days of therapy and longer lengths of stay. In multivariate analyses, ABR, MDR, SARS-CoV-2-positive status, respiratory source, and prior admissions were identified as key IET risk factors.

CONCLUSIONS

IET remained a persistent problem during the COVID-19 pandemic and occurred at higher rates in patients with ABR/MDR bacteria or a co-SARS-CoV-2 infection.

Impact of Antibiotic Consumption on Antimicrobial Resistance to Invasive Hospital Pathogens

The aim of our investigation is to correlate the wholesale data on antibiotic consumption expressed in daily doses per 1000 inhabitants per day (DID) with the resistance rate of invasive pathogen bacteria from 2017 to 2021. The data on antimicrobial resistance were collected from an analysis of the primary isolates of hospitalized patients. According to the CAESAR manual, the selected pathogens isolated from blood culture and cerebrospinal fluids were tested. The consumption of antibiotics for systematic use showed a statistically significant increasing trend (β = 0.982, p = 0.003) from 21.3 DID in 2017 to 34.5 DID in 2021. The ratio of the utilization of broad-spectrum to narrow-spectrum antibiotics increased by 16% (β = 0.530, p = 0.358). The most consumed antibiotic in 2021 was azithromycin (15% of total consumption), followed by levofloxacin (13%) and cefixime (12%). A statistically positive significant correlation was discovered between the percentage of resistant isolates of K. pneumoniae and consumption of meropenem (r = 0.950; p = 0.013), ertapenem (r = 0.929; p = 0.022), ceftriaxone (r = 0.924; p = 0.025) and levofloxacin (r = 0.983; p = 0.003). Additionally, the percentage of resistant isolates of E. coli and consumption of ertapenem showed significant correlation (r = 0.955; p = 0.011). Significant correlation with consumption of the antibiotics widely used at the community level, such as levofloxacin, and resistance isolated in hospitals indicates that hospital stewardship is unlikely to be effective without a reduction in antibiotic misuse at the community level.

Carbapenem-resistant Acinetobacter baumannii: A challenge in the intensive care unit

Carbapenem-resistant Acinetobacter baumannii (CRAB) has become one of the leading causes of healthcare-associated infections globally, particularly in intensive care units (ICUs). Cross-transmission of microorganisms between patients and the hospital environment may play a crucial role in ICU-acquired CRAB colonization and infection. The control and treatment of CRAB infection in ICUs have been recognized as a global challenge because of its multiple-drug resistance. The main concern is that CRAB infections can be disastrous for ICU patients if currently existing limited therapeutic alternatives fail in the future. Therefore, the colonization, infection, transmission, and resistance mechanisms of CRAB in ICUs need to be systematically studied. To provide a basis for prevention and control countermeasures for CRAB infection in ICUs, we present an overview of research on CRAB in ICUs, summarize clinical infections and environmental reservoirs, discuss the drug resistance mechanism and homology of CRAB in ICUs, and evaluate contemporary treatment and control strategies.

Study on the Detection and Infection Distribution of Multidrug-Resistant Organisms in Different Specimens

Objective

To analyze the infection and distribution of multidrug-resistant organisms (MDRO) in different clinical specimens, thereby providing a reference for clinical diagnosis and treatment and prevention and control.

Patient and Methods

2314 strains of MDRO isolated from clinical specimens in the First Affiliated Hospital of Nanjing Medical University from January to December 2020. MDRO were collected by Information System. The detection rate of MDRO, infection rate, the proportion of infection, and detection rate of MDRO infection in different specimens were analyzed.

Results

The top three specimens in the detection rate of MDRO were BALF (60.71%), sputum (33.68%), and blood (28.79%). The top three specimens in the proportion of MDRO infection were blood (97.74), other sterile body fluids (90.35%), and BALF (90.20%). The top three specimens in the MDRO infection rate were BALF (9.75%), sputum (3.07%), and secretions (2.90%). The top three specimens in the detection rate of MDRO infection were sputum (0.63‰), other sterile body fluids (0.13‰), and secretions (0.11‰).

Conclusion

The detection and infection distribution of MDRO vary greatly in different specimens. The submission of sterile body fluids for examination should be strengthened and the standard of sample collection should be highlighted.

A multimodal intervention to optimise antimicrobial use in residential aged care facilities (ENGAGEMENT): protocol for a stepped-wedge cluster randomised trial

BACKGROUND

Inappropriate antibiotic use can cause harm and promote antimicrobial resistance, which has been declared a major health challenge by the World Health Organization. In Australian residential aged care facilities (RACFs), the most common indications for antibiotic prescribing are for infections of the urinary tract, respiratory tract and skin and soft tissue. Studies indicate that a high proportion of these prescriptions are non-compliant with best prescribing guidelines. To date, a variety of interventions have been reported to address inappropriate prescribing and overuse of antibiotics but with mixed outcomes. This study aims to identify the impact of a set of sustainable, multimodal interventions in residential aged care targeting three common infection types.

METHODS

This protocol details a 20-month stepped-wedge cluster-randomised trial conducted across 18 RACFs (as 18 clusters). A multimodal multi-disciplinary set of interventions, the 'AMS ENGAGEMENT bundle', will be tailored to meet the identified needs of participating RACFs. The key elements of the intervention bundle include education for nurses and general practitioners, telehealth support and formation of an antimicrobial stewardship team in each facility. Prior to the randomised sequential introduction of the intervention, each site will act as its own control in relation to usual care processes for antibiotic use and stewardship. The primary outcome for this study will be antibiotic consumption measured using defined daily doses (DDDs). Cluster-level rates will be calculated using total occupied bed numbers within each RACF during the observation period as the denominator. Results will be expressed as rates per 1000 occupied bed days. An economic analysis will be conducted to compare the costs associated with the intervention to that of usual care. A comprehensive process evaluation will be conducted using the REAIM Framework, to enable learnings from the trial to inform sustainable improvements in this field.

DISCUSSION

A structured AMS model of care, incorporating targeted interventions to optimise antimicrobial use in the RACF setting, is urgently needed and will be delivered by our trial. The trial will aim to empower clinicians, residents and families by providing a robust AMS programme to improve antibiotic-related health outcomes.

TRIAL REGISTRATION

US National Library of Medicine Clinical Trials.gov ( NCT04705259 ). Prospectively registered in 12th of January 2021.

Epidemiological and genetic characteristics of vancomycin-resistant Enterococcus faecium isolates in a University Children's Hospital in Germany: 2019 to 2020

BACKGROUND

Vancomycin-resistant Enterococcus faecium (VREfm) strains are one of the most important pathogens causing nosocomial infections in Germany. Due to limited treatment options and an increased risk for acquisition in immunocompromised children, surveillance to monitor occurrence of VREfm in paediatric clinical facilities is of critical importance. Following an unusual accumulation of VREfm positive patients between April 2019 and August 2020 at Dr. von Hauner Children's Hospital in Munich, Germany, our study aimed to identify dynamics and routes of transmission, and analyse the affected population in view of previously described host risk factors for VREfm colonisation or infection.

METHODS

The hospital database was used to collect epidemiological and clinical data of VREfm cases. Descriptive statistical analyses were conducted to outline patient characteristics and depict possible differences between VREfm-colonised and -infected children. An outbreak investigation determining genetic relatedness among VREfm isolates was performed by core genome multilocus sequence typing (cgMLST). To examine potential transmission pathways, results of genome analysis were compared with epidemiological and clinical data of VREfm positive patients.

RESULTS

VREfm acquisition was documented in a total of 33 children (< 18 years). Seven VREfm-colonised patients (21.2%), especially those with a haemato-oncological disease (4/7; p = 0.011), showed signs of clinical infection. cgMLST analysis revealed seven distinct clusters, demonstrating a possible connection within each clonal lineage. Additional eight singletons were identified. Comparison with epidemiological and clinical data provided strong evidence for a link between several VREfm positive patients within the hospital.

CONCLUSIONS

A nosocomial spread-at least in part-was the most likely reason for the unusual accumulation of VREfm cases. The study highlights that there is a constant need to increase efforts in hygiene measures, infection control and antibiotic stewardship to combat VREfm transmission events within German paediatric hospitals. Continuous monitoring of adherence to respective policies might reduce the occurrence of clustered cases and prevent future outbreaks.

Evaluation of Antibiotic Duration after Surgical Debridement of Necrotizing Soft Tissue Infection

Background: Necrotizing soft tissue infection (NSTI) is known to be a medical emergency with high morbidity and mortality. Guidelines do not specify the optimal duration of antibiotic agents after completion of surgical debridements of NSTI, which has created variable practice. It was hypothesized that patients with NSTI who receive 48 hours or less of post-operative antibiotic agents after final debridement have similar rates of subsequent intervention or infection recurrence, suggesting that a shorter duration of antibiotic agents may treat NSTI adequately after final surgical debridement. Patients and Methods: This was a retrospective study including adults with NSTI identified through International Classification of Diseases, Ninth Revision (ICD-9), International Classification of Diseases, Tenth Revision (ICD-10), and Current Procedural Terminology (CPT) codes admitted to one academic institution between January 1, 2010 and July 31, 2020. Demographics, surgical practices, antibiotic practices, and clinical outcomes including inpatient mortality, hospital length of stay (LOS), intensive care unit (ICU) LOS, total antibiotic days, necrotizing infection clinical composite end point (NICCE) success, and infection recurrence were compared based on the duration of antibiotic agents after final debridement. Results: Three hundred twenty-two patients with NSTI were included and baseline characteristics and clinical severity markers were well balanced between the two groups. In 71 patients (22%) who received less than 48 hours of antibiotic agents after final debridement there was no difference in recurrence (1.4% vs. 3.6%; p = 0.697), mortality (1.4% vs. 4.4%; p = 0.476), or ICU LOS (1 vs. 2 days; p = 0.300], but they did have a shorter hospital LOS (7 vs. 10 days; p = 0.011). Conclusions: Shorter duration of antibiotic therapy after final surgical debridement of NSTI may be appropriate in patients without another indication for antibiotic agents.

Correlation between antibiotic consumption and the occurrence of multidrug-resistant organisms in a Malaysian tertiary hospital: a 3-year observational study

Inappropriate use of antibiotics has been shown to contribute to the occurrence of multidrug-resistant organisms (MROs). A surveillance study was performed in the largest tertiary care hospital in Kuala Lumpur, Malaysia, from 2018 to 2020 to observe the trends of broad-spectrum antibiotics (beta-lactam/beta-lactamases inhibitors (BL/BLI), extended-spectrum cephalosporins (ESC), and fluoroquinolones (FQ)) and antibiotics against MRO (carbapenems, polymyxins, and glycopeptides) usage and the correlation between antibiotic consumption and MROs. The correlation between 3-year trends of antibiotic consumption (defined daily dose (DDD)/100 admissions) with MRO infection cases (per 100 admissions) was determined using a Jonckheere-Terpstra test and a Pearson's Correlation coefficient. The antimicrobial resistance trend demonstrated a positive correlation between ESC and FQ towards the development of methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase (ESBL)-producing Klebsiella spp, ESBL-producing Escherichia coli (E. coli), and MRO Acinetobacter baumannii (A. baumannii). Increasing carbapenem consumption was positively correlated with the occurrence of ESBL-producing Klebsiella spp and E. coli. Polymyxin use was positively correlated with ESBL-producing Klebsiella spp, MRO A. baumannii, and carbapenem-resistant Enterobacteriaceae. The findings reinforced concerns regarding the association between MRO development, especially with a surge in ESC and FQ consumption. Stricter use of antimicrobials is thus crucial to minimise the risk of emerging resistant organisms.

Comparing Treatment Outcomes of Ampicillin-Sulbactam, Other β-Lactams, and Vancomycin in Blood Culture-Negative Infective Endocarditis

Selection of proper antibiotics for blood culture-negative infective endocarditis (BCNIE) is difficult due to limited data on antibiotic regimens for BCNIE in existing literature. The aim of this study was to compare ampicillin-sulbactam, other β-lactams antibiotics, and vancomycin among patients with BCNIE to determine the proper antibiotic regimens. This retrospective study included adult patients with BCNIE admitted to Severance Hospital from November 2005 to August 2017. Patients were classified into three groups as, treated with ampicillin-sulbactam, other β-lactams, and vancomycin. The primary outcome was 1-year all-cause mortality. A total of 74 cases with BCNIE were enrolled in this study. There were no statistically significant differences in clinical characteristics between the three groups. One-year mortality did not significantly differ between the study groups either. Further, in-hospital mortality, 28-day mortality and overall mortality showed no difference. However, Cox-regression analysis showed nosocomial infective endocarditis as an independent risk factor and a protective effect of surgery on 1-year mortality. This study showed no clear difference in the outcomes of BCNIE as per the antibiotic therapy but suggested the beneficial effect of surgical treatment. With increasing global concern of antimicrobial resistance, it might be reasonable to select ampicillin-sulbactam-based antibiotic therapy while actively considering surgical treatment in BCNIE.

The role of antimicrobial stewardship in preventing KPC-producing Klebsiella pneumoniae

Antimicrobial stewardship programmes are widely considered to be a core component of the response to the antimicrobial resistance threat. However, a positive impact of these interventions in terms of microbiological outcomes remains difficult to demonstrate, especially when focusing on specific resistant phenotypes. The first part of this review aims to explore the complex relationship between antibiotic exposure and resistance development in KPC-producing Klebsiella pneumoniae. In the second part we aim to summarize published examples of antimicrobial stewardship interventions intended to impact on the epidemiology of KPC-producing K. pneumoniae. For this purpose, a literature search was performed and seven studies were included in the review. Both restrictive and non-restrictive interventions were associated with an overall reduction in antibiotic consumption, and a decrease in carbapenem resistance rates was observed in five studies. The overall quality of the evidence was low, mainly due to the poor reporting of microbiological outcomes, lack of a control group and suboptimal study design. Although the link between antibiotic use and resistance development is supported by strong evidence, demonstrating the impact of antimicrobial stewardship interventions on microbiological outcomes remains difficult. Studies with adequate design and appropriate outcome measures are needed to further promote antimicrobial stewardship and elucidate which interventions are more successful for controlling the spread of KPC-producing K. pneumoniae.

Reducing Piperacillin and Tazobactam Use for Pediatric Perforated Appendicitis

BACKGROUND

Although perforated appendicitis is associated with infectious complications, the choice of antibiotic therapy is controversial. We assess the effectiveness and safety of an intervention to reduce piperacillin and tazobactam (PT) use for pediatric acute perforated appendicitis.

METHODS

This is a single-center, retrospective cohort study of children 18 y of age or younger who underwent primary appendectomy for perforated appendicitis between January 01, 2016 and June 30, 2019. An intervention to decrease PT use was implemented: the first phase was provider education (April 19, 2017) and the second phase was modification of electronic antibiotic orders to default to ceftriaxone and metronidazole (July 06, 2017). Preintervention and postintervention PT exposure, use of PT ≥ half of intravenous antibiotic days, and clinical outcomes were compared.

RESULTS

Forty children before and 109 after intervention were included and had similar baseline characteristics. PT exposure was 31 of 40 (78%) and 20 of 109 (18%) (P < 0.001), and use ≥ half of intravenous antibiotic days was 31 of 40 (78%) and 14 of 109 (13%) (P < 0.001), in the preintervention and postintervention groups, respectively. There was no significant difference in mean duration of antibiotic therapy (10.8 versus 9.8 d), mean length of stay (6.2 versus 6.5 d), rate of surgical site infection (10% versus 11%), or rate of 30-d readmission and emergency department visit (20% versus 20%) between the preintervention and postintervention periods, respectively.

CONCLUSIONS

Provider education and modification of electronic antibiotic orders safely reduced the use of PT for pediatric perforated appendicitis.

Antibiotic modification versus withhold in febrile patients without evidence of bacterial infection, unresponsive to initial empiric regimen: a multicentre retrospective study conducted in Israel

Prescribing antibiotics for febrile patients without proof of bacterial infection contributes to antimicrobial resistance. Lack of clinical response in these patients often leads to antibiotic escalation, although data supporting this strategy are scarce. This study compared outcomes of modifying, withholding, or continuing the same antibiotic regimen for such patients. Febrile or hypothermic stable patients with suspected infection, unresponsive to empiric antibiotic treatment, admitted to one of 15 internal medicine departments in three hospitals during a 5-year study period, were included. Patients with a definitive clinical or microbiological bacterial infection, malignancy, immunodeficiency, altered mental status, or need for mechanical ventilation were excluded. Participants were divided into groups based on treatment strategy determined 72 h after antibiotic initiation: antibiotic modified, withheld or continued. Outcomes measured included in-hospital and 30-day post-discharge-mortality rates, length of hospital stay (LOS) and days of antimicrobial therapy (DOT). A total of 486 patients met the inclusion criteria: 124 in the Antibiotic modified group, 67 in the Antibiotic withheld group and 295 in the Initial antibiotic continued group. Patient characteristics were similar among groups with no differences in mortality rates in-hospital (23% vs. 25% vs. 20%, p = 0.58) and within 30 days after discharge (5% vs. 3% vs. 4%, p = 0.83). Changing antibiotics led to longer LOS (9.0 ± 6.8 vs. 6.2 ± 5.6 days, p = 0.003) and more DOT (8.6 ± 6.0 vs. 3.2 ± 1.0 days, p < 0.001) compared to withholding treatment. Withholding as compared to modifying antibiotics, in febrile patients with no clear evidence of bacterial infection, is a safe strategy associated with decreased LOS and DOT.

Cohorting for preventing the nosocomial spread of Carbapenemase-Producing Enterobacterales, in non-epidemic settings: is it mandatory?

BACKGROUND

Worldwide dissemination of Carbapenemase-Producing Enterobacterales (CPE) has led to national and international guidance recommending the implementation of cohorting in healthcare settings (HS). However, in view of recent data regarding the spread of Extended-spectrum Beta-lactamase-producing Enterobacterales, we may wonder about the usefulness of this measure in a non-outbreak settings; here, individual contact isolation may be sufficient to control the risk of dissemination.

AIM/METHODS

We conducted a narrative review of the literature and discussed the role of cohorting.

FINDINGS

CPE are responsible for outbreaks in HS, which are considered the epicentre of spread of resistance strains. CPE are responsible for adverse effects such as increases in hospital stay and costs, less therapeutic options and thus higher risk of clinical failures and mortality. Environment and materials have also been described contaminated with CPE and can be the source of outbreak. Even if guidelines and publications have supported implementation of cohorting, there are no randomized studies demonstrating the mandatory nature of this measure. Most studies are descriptive and cohorting is usually one of several other measures to control outbreaks. Cohorting is not adapted to all HS, which requires human and material resources. Other measures must be strengthened such as compliance of hand hygiene, antibiotic stewardship and surveillance of contact patients. Individual risk factors of acquisition should also be evaluated.

CONCLUSION

Local epidemiology and resources must be assessed before implementing cohorting.

Outcomes of Infected versus Symptomatic Sterile Walled-Off Pancreatic Necrosis Treated with a Minimally Invasive Therapy

Background/Aims

Acute pancreatitis complicated by walled-off necrosis (WON) is associated with high morbidity and mortality, and if infected, typically necessitates intervention. Clinical outcomes of infected WON have been described as poorer than those of symptomatic sterile WON. With the evolution of minimally invasive therapy, we sought to compare outcomes of infected to symptomatic sterile WON.

Methods

We performed a retrospective cohort study examining patients who were undergoing dual-modality drainage as minimally invasive therapy for WON at a high-volume tertiary pancreatic center. The main outcome measures included mortality with a drain in place, length of hospital stay, admission to intensive care unit, and development of pancreatic fistulae.

Results

Of the 211 patients in our analysis, 98 had infected WON. The overall mortality rate was 2.4%. Patients with infected WON trended toward higher mortality although not statistically significant (4.1% vs 0.9%, p=0.19). Patients with infected WON had longer length of hospitalization (29.8 days vs 17.3 days, p<0.01), and developed more spontaneous pancreatic fistulae (23.5% vs 7.8%, p<0.01). Multivariate analysis showed that infected WON was associated with higher odds of spontaneous pancreatic fistula formation (odds ratio, 2.65; 95% confidence interval, 1.20 to 5.85).

Conclusions

This study confirms that infected WON has worse outcomes than sterile WON but also demonstrates that WON, once considered a significant cause of death, can be treated with good outcomes using minimally invasive therapy.

The Infinity War: How to Cope with Carbapenem-resistant Enterobacteriaceae

Carbapenem-resistant Enterobacteriaceae (CRE) are now spread worldwide. In Korea, the number of CRE isolation is rapidly increasing, and impending endemicity is a concern. To cope well with CRE, thorough infection control, such as active surveillance, early detection, strict contact precaution, cleaning the environment, and antibiotic stewardship is very important. Therapeutic options include polymyxin, tigecycline, fosfomycin or the combination of them with carbapenem, which is currently the mainstay of treatment. In addition, various combination regimens with new carbapenemase inhibitors such as avibactam, vaborbactam, or relebactam, and other classes of antimicrobials such as plazomicin and siderophore cephalosporin are in the process of evaluation.

Impact of an infectious diseases advanced pharmacy practice experience on student knowledge

INTRODUCTION

The goal of this assessment was to determine knowledge acquisition by pharmacy students during an infectious diseases (ID) advanced pharmacy practice experience (APPE).

METHODS

A 50-question knowledge-based examination was given to every student on a five-week ID APPE between July 1, 2013 and May 5, 2017. The examination was also given to control students (those who did not have an ID APPE) immediately prior to graduation. The primary outcome was difference in examination performance after completion of the ID APPE. Secondary outcomes included correlations between examination performance and number of previous inpatient clinical rotations (ICR), average score in therapeutic coursework (TC), and rotation block (RB).

RESULTS

Forty students were included (control = 5, experimental = 35). Average pre-test scores were similar between experimental and control students [61.7 (10.9)% versus 62.0 (5.1)%, respectively], but experimental post-test scores [80.2 (7.9)%] were significantly better than pre-test scores for both experimental (p < .05) and control student (p < .05) examination scores. ICR [1.3 (1.0) rotations], TC [81.5 (3.9)%], and RB (median = 4) had a positive correlation with pre-examination performance (R = .5, .5, and .4, respectively).

DISCUSSION

Improved ID pharmacotherapy knowledge is needed. Baseline scores of students taking an ID elective were similar to control students who completed the entire year of APPEs, and knowledge scores were higher in ID students after APPE completion. There was a positive, but not strong, correlation between pre-examination performance and number of previous rotations, therapeutic coursework, and rotation block.

CONCLUSION

A five-week ID elective APPE improved student performance on a knowledge-based examination. Consideration should be given to more consistent integration of ID principles across all rotation types.

Inappropriate Use of Antimicrobials for Lower Respiratory Tract Infections in Elderly Patients: Patient- and Community-Related Implications and Possible Interventions

The elderly are more susceptible to infections, which is reflected in the incidence and mortality of lower respiratory tract infections (LRTIs) increasing with age. Several aspects of antimicrobial use for LRTIs in elderly patients should be considered to determine appropriateness. We discuss possible differences in microbial etiology between elderly and younger adults, definitions of inappropriate antimicrobial use for LRTIs currently found in the literature, along with their results, and the possible negative impact of antimicrobial therapy at both an individual and community level. Finally, we propose that both antimicrobial stewardship interventions and novel rapid diagnostic techniques may optimize antimicrobial use in elderly patients with LRTIs.

Antimicrobial resistance (AMR) nanomachines-mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation

In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics-the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that trigger and regulate a wide variety of possible resistance mechanisms, we propose that these antimicrobial resistance mechanisms might be considered complex 'nanomachines' that drive survival of bacterial cells in antibiotic environments.

Deconstructing the relative benefits of a universal glove and gown intervention on MRSA acquisition

BACKGROUND

The 20-site Benefits of Universal Glove and Gown (BUGG) study found that wearing gloves and gowns for all patient contacts in the intensive care unit (ICU) reduced acquisition rates of meticillin-resistant Staphylococcus aureus (MRSA). The relative importance of gloves and gowns as a barrier, improved hand hygiene, and reduced healthcare worker (HCW)-patient contact rates is unknown.

AIM

To determine what proportion of the reduction in acquisition rates observed in the BUGG study was due to improved hand hygiene, reduced contact rates, and universal glove and gown use using agent-based simulation modelling.

METHODS

An existing agent-based model to simulate MRSA transmission dynamics in an ICU was modified, and the model was calibrated using site-specific data. Model validation was completed using data collected in the BUGG study. A full 2^k factorial design was conducted to quantify the relative benefits of improving each of the aforementioned factors with respect to MRSA acquisition rates.

FINDINGS

Across 40 simulated replications for each factorial design point and intervention site, approximately 44% of the decrease in MRSA acquisition rates was due to universal glove and gown use, 38.1% of the decrease was due to improvement in hand hygiene compliance on exiting patient rooms, and 14.5% of the decrease was due to the reduction in HCW-patient contact rates.

CONCLUSION

Using mathematical modelling, the decrease in MRSA acquisition in the BUGG study was found to be due primarily to the barrier effects of gowns and gloves, followed by improved hand hygiene and lower HCW-patient contact rates.