VRE acquisition in hospital and its association with hospital antimicrobial usage -a non-linear analysis of an extended time series

BACKGROUND

Vancomycin resistant enterococci (VRE) have become endemic pathogens in many Australian hospitals causing significant morbidity. There are few observational studies that have evaluated the effect of antibiotic usage on VRE acquisition. This study examined VRE acquisition and its association with antimicrobial use. The setting was a NSW tertiary hospital with 800 beds over a 63 month period up to March 2020, straddling piperacillin-tazobactam (PT) shortages that occurred from in September 2017.

METHODS

The primary outcome was monthly inpatient hospital onset Vancomycin-resistant Enterococci (VRE) acquisitions. Multivariate adaptive regression splines (MARS) were used to estimate hypothetical thresholds, where antimicrobial use above threshold is associated with increased incidence of hospital onset VRE acquisition. Specific antimicrobials and categorised usage (broad, less broad and narrow spectrum) were modelled.

RESULTS

There were 846 hospital onset VRE detections over the study period. Hospital onset vanB and vanA VRE acquisitions fell significantly by 64% and 36% respectively after the PT shortage. MARS modelling indicated that PT usage was the only antibiotic found to exhibit a meaningful threshold. PT usage greater than 17.4 defined daily doses/1000 occupied bed-days (95%C I: 13.4, 20.5) was associated with higher onset of hospital VRE.

CONCLUSIONS

This paper highlights the large, sustained impact that reduced broad spectrum antimicrobial use had on VRE acquisition and showed that PT use in particular was a major driver with a relatively low threshold. It raises the question as to whether hospitals should be determining local antimicrobial usage targets based on direct evidence from local data analysed with non-linear methods.

The effectiveness of an antimicrobial stewardship program in an Australian rural hospital

OBJECTIVE

The aim of this study was to investigate the type, indication and duration of restricted antibiotics prescribed to inpatients who had undergone antimicrobial stewardship (AMS) review by the infectious diseases specialist and to assess the effectiveness of the AMS program in a rural hospital.

DESIGN

This was an observational retrospective study.

SETTING

The study was conducted at a rural referral hospital in NSW.

PARTICIPANTS

Inpatients from the medical, surgical and intensive care units were included.

MAIN OUTCOME MEASURES

The main outcome measure was the type, indication and average duration of restricted antibiotics that were reviewed in the AMS rounds. The rate of adherence to AMS advice and the rate of step-down of antibiotics after AMS advice were other outcome measures. Data on participant characteristics were also collected.

RESULTS

The most commonly prescribed restricted antibiotic in medicine and surgery was amoxicillin-clavulanic acid (28%), followed by ceftriaxone (15%) and piperacillin-tazobactam (10%), with the most common indication being intra-abdominal infection (37%). In intensive care, ceftriaxone (16.7%) and piperacillin-tazobactam (16.7%) were most prescribed, and the most common indication was community-acquired pneumonia (24.5%). The adherence rate to AMS advice was 86% in medicine and surgery and 83% in intensive care. AMS rounds managed to cease or step down antibiotics 60% of the time.

CONCLUSION

The AMS program in a rural hospital was effective with an overall AMS advice adherence rate of 84.5% which measures well against tertiary-level centres. Continued AMS and advocacy of such programs in rural regions are fundamental to optimising patient outcomes in the rural community.

Think before you prescribe: how dentistry contributes to antibiotic resistance

Antibiotic resistance presents a daunting challenge to health professionals worldwide and has the potential to create major problems for modern health care, resulting in more medical expenditure, extended hospital stays and increased morbidity and mortality. Advanced genome sequencing technologies present a complex picture of resistance, extending our understanding beyond the pharmacotherapeutic interface between pathogens and antibiotics. This review discusses the global scope and scale of antibiotic resistance and contextualizes it for the dental practitioner, emphasizing the role we must play in limiting the progression of resistance through antibiotic stewardship and disease prevention.