Evaluating the economic effects of genomic sequencing of pathogens to prioritise hospital patients competing for isolation beds

Objective This study compared the costs and patient movements of a new hospital protocol to discontinue contact precautions for patients with non-multiresistant methicillin-resistant Staphylococcus aureus (nmMRSA), based on whole-genome sequencing (WGS) of pathogens with current practice. Methods A hybrid simulation model was constructed and analysed over a 12-month time horizon. Six multidrug-resistant organisms and influenza were modelled concurrently where infected patients competed for isolation beds. Model inputs included pathogen incidence, resources for WGS, staff and contact precautions, hospital processes, room allocations and their associated costs. Data were sourced from aggregated records of patient admissions during 2017-18, clinical records and published reports. Results The WGS protocol resulted in 389 patients isolated (44% of current practice), 5223 'isolation bed days' (56%) and 268 closed-bed days (88%). Over 1 year, the mean (±s.d.) total cost for the WGS protocol was A$749243±126667; compared with current practice, the overall cost savings were A$690864±300464. Conclusion Using WGS to inform infection control teams of pathogen transmission averts patients from isolation rooms and reduces significant resources involved in implementing contact precautions. What is known about the topic? There are an estimated 265000 hospital-acquired infections (HAI) in Australia each year. WGS can accurately identify the genetic lineage among HAIs and determine transmission clusters that can help infection control staff manage patients. Economic appraisals are lacking to inform whether pathogen genomics services should be adopted within already-stretched hospital budgets. What does this paper add? An isolation protocol using pathogen genomics to provide additional information on the relatedness of a pathogen between colonised patients showed favourable results for healthcare costs and patient flow. Using WGS, in a confirmatory role, to discontinue certain patients from contact precautions and isolation rooms resulted in cost savings of A$690864 across 1 year for a single major hospital. What are the implications for practitioners? Using pathogen WGS services for infection control potentially curbs hospital spending, averts patient isolations and improves patient flow within hospitals.

Diagnosis of melioidosis: the role of molecular techniques

Melioidosis is an emerging infectious disease with an estimated global burden of 4.64 million disability-adjusted life years per year. A major determinant related to poor disease outcomes is delay to diagnosis due to the fact that identification of the causative agent Burkholderia pseudomallei may be challenging. Over the last 25 years, advances in molecular diagnostic techniques have resulted in the potential for rapid and accurate organism detection and identification direct from clinical samples. While these methods are not yet routine in clinical practice, laboratory diagnosis of infectious diseases is transitioning to culture-independent techniques. This review article aims to evaluate molecular methods for melioidosis diagnosis direct from clinical samples and discuss current and future utility and limitations.

A hybrid simulation model approach to examine bacterial genome sequencing during a hospital outbreak

Background

Hospital infection control requires timely detection and identification of organisms, and their antimicrobial susceptibility. We describe a hybrid modeling approach to evaluate whole genome sequencing of pathogens for improving clinical decisions during a 2017 hospital outbreak of OXA-181 carbapenemase-producing Escherichia coli and the associated economic effects.

Methods

Combining agent-based and discrete-event paradigms, we built a hybrid simulation model to assess hospital ward dynamics, pathogen transmission and colonizations. The model was calibrated to exactly replicate the real-life outcomes of the outbreak at the ward-level. Seven scenarios were assessed including genome sequencing (early or late) and no sequencing (usual care). Model inputs included extent of microbiology and sequencing tests, patient-level data on length of stay, hospital ward movement, cost data and local clinical knowledge. The main outcomes were outbreak size and hospital costs. Model validation and sensitivity analyses were performed to address uncertainty around data inputs and calibration.

Results

An estimated 197 patients were colonized during the outbreak with 75 patients detected. The total outbreak cost was US$318,654 with 6.1% of total costs spent on sequencing. Without sequencing, the outbreak was estimated to result in 352 colonized patients costing US$531,109. Microbiology tests were the largest cost component across all scenarios.

Conclusion

A hybrid simulation approach using the advantages of both agent-based and discrete-event modeling successfully replicated a real-life bacterial hospital outbreak as a foundation for evaluating clinical outcomes and efficiency of outbreak management. Whole genome sequencing of a potentially serious pathogen appears effective in containing an outbreak and minimizing hospital costs.

Association between higher ambient temperature and orthopaedic infection rates: a systematic review and meta-analysis

INTRODUCTION

Many infectious diseases display seasonal variation corresponding with particular conditions. In orthopaedics a growing body of evidence has identified surges in post-operative infection rates during higher temperature periods. The aim of this research was to collate and synthesize the current literature on this topic.

METHODS

A systematic review and meta-analysis was performed using five databases (PubMed, Embase, CINAHL, Web of Science and Central (Cochrane)). Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation method. Odds ratios (ORs) were calculated from monthly infection rates and a pooled OR was generated using the DerSimonian and Lairds method. A protocol for this review was registered with the National Institute for Health Research International Prospective Register of Systematic Reviews (CRD42017081871).

RESULTS

Eighteen studies analysing over 19 000 cases of orthopaedic related infection met inclusion criteria. Data on 6620 cases and 9035 controls from 12 studies were included for meta-analysis. The pooled OR indicated an overall increased odds of post-operative infection for patients undergoing orthopaedic procedures during warmer periods of the year (pooled OR 1.16, 95% confidence interval 1.04-1.30).

CONCLUSION

A small but significantly increased odds of post-operative infection may exist for orthopaedic patients who undergo procedures during higher temperature periods. It is hypothesized that this effect is geographically dependent and confounded by meteorological factors, local cultural variables and hospital staffing cycles.

The effectiveness of targeted relative to empiric prophylaxis on infectious complications after transrectal ultrasound-guided prostate biopsy: a meta-analysis

PURPOSE

Rectal culture screening for fluoroquinolone (FQ)-resistant Enterobacteriaceae before transrectal ultrasound guided prostate (TRUSPB) biopsy and targeted antibiotic prophylaxis (TAP) may decrease post-TRUSPB infection rates compared to empiric (EAP) regimens. The objective of this study was to evaluate the effectiveness of targeted relative to empiric prophylaxis regimens on rates of infectious complications after TRUSPB and to determine the baseline prevalence of FQ resistance based on prior rectal swabs.

METHODS

An electronic search within literature databases including EMBASE and Web of Science (all databases) for articles assessing TAP as an approach to TRUSPB prophylaxis was conducted. Quality assessment was performed using the Hoy instrument. Meta-analysis was performed using MetaXL 5.3.

RESULTS

From 15 studies (eight retrospective and seven prospective) representing 12,320 participants, infectious complication incidence was 3.4% in EAP and 0.8% in TAP patients. The number needed to treat with TAP to avoid one more infection when compared to the EAP group was 39. Effect sizes were homogeneous. Prevalence of FQ resistance showed low (15%) and high (28%) subgroups, likely due to region of origin (within and outside USA, respectively).

CONCLUSIONS

Rectal culture prior to TRUSPB and use of TAP adjusts for endemic FQ resistance and is associated with less infectious complications and resulting morbidity when compared to EAP. Overtreatment associated with augmented prophylaxis approaches may be reduced as a result. Further prospective assessment and cost-benefit analyses are required before widespread implementation can be recommended.

Comparison of fosfomycin against fluoroquinolones for transrectal prostate biopsy prophylaxis: an individual patient-data meta-analysis

PURPOSE

To systematically review and meta-analyse available evidence comparing fosfomycin trometamol (FT) to fluoroquinolone (FQ) prophylaxis to prevent transrectal ultrasound-guided prostate biopsy (TRUSPB) related infectious complications.

METHODS

Electronic databases were queried for studies comparing FT to FQ-based TRUSPB prophylaxis. Studies were assessed for comparable outcomes and methodological quality (ROBINS-I modification). The primary outcome measure was the relative odds of overall infectious complications following TRUSPB according to FT/FQ treatment, which was evaluated with meta-analysis. Safety and tolerability were also assessed. The relative odds of infections of different severity [Grade 1, bacteriuria and afebrile urinary tract infection (UTI); Grade 2, bacteraemia, febrile UTI, and urosepsis] according to FT/FQ treatment were also estimated.

RESULTS

Five studies, being three prospective randomised trials and two retrospective cohort studies, representing 3112 patients, were included. The relative odds of an infectious complication (OR 0.22, 95% CI 0.09-0.54) or of a more severe (Grade 2) infection (OR 0.13, 95% CI 0.07-0.26) were significantly lower in those receiving FT compared to FQ prophylaxis. A low incidence of medication-related side effects was observed. There were less observed infections due to FQ-resistant pathogens in those receiving FT prophylaxis.

CONCLUSIONS

Patients who received FT prophylaxis were less likely than those who received FQ prophylaxis to develop infections overall, as well as severe and resistant infections after TRUSPB. Assessing the performance of FT in other geographic locations or in comparison to targeted prophylaxis based on risk assessment or rectal cultures is desired.

Endocardial tumors induced by carbamate or fluorenylacetamide derivatives in rats

Endocardial tumors were induced in 18 rats treated with derivatives of carbamates and in 4 rats treated with derivatives of fluorenylacetamide. The endocardial tumor of 1 rat treated with N,N'-2,7-fluorenylenebisacetamide metastasized to the lung. This is the first report of metastasis of an endocardial tumor. Among the more than 60,000 accessions at the Registry of Experimental Cancers, Division of Cancer Cause and Prevention, National Cancer Institute, there are 4 untreated rats with endocardial tumors. On the basis of the light microscopic morphology, we have classified these endocardial tumors as mesenchymal.

Carcinogenicity of three dose levels of 1,4-Bis(4-fluorophenyl)-2-propynyl-N-cyclooctyl carbamate in male Sprague-Dawley and F344 rats

Feeding 1,4-bis(fluorophenyl)-2-propynyl-N-cyclooctyl carbamate to F344 or Sprague-Dawley male rats at 125-500 ppm in the diet led to many carcinomas of the small intestine and ear duct (Zymbal's gland tumors) in addition to lymphomas and leukemias. A high incidence of mammary adenocarcinomas was found in the Sprague-Dawley rats. Only a few colon or liver tumors were observed in each strain.

Vaccinal Infection of the Chorioallantoic Membrane of the Turtle Embryo

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Aneurysmal Dilatation of the Cardiac Coronary Arteries: Review of the Literature and Report of a Case

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Adenocystoma Lymphomatosum of the Salivary Glands: Report of Two Cases

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Multiple Liver Abscesses Caused by a Leptothrix, with a Review of Leptothrical Infection

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Histological Study of a Case of the Eastern Type of Rocky Mountain Spotted Fever

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