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Enterohaemorrhagic Escherichia coli (EHEC) O157 : H7 is naturally exposed to a wide variety of stresses including gastric acid shock, and yet little is known about how this stress influences virulence. This study investigated the impact of acid stress on several critical virulence properties including survival, host adhesion, Shiga toxin production, motility and induction of host-cell apoptosis. Several acid-stress protocols with relevance for gastric passage as well as external environmental exposure were included. Acute acid stress at pH 3 preceded by acid adaptation at pH 5 significantly enhanced the adhesion of surviving organisms to epithelial cells and bacterial induction of host-cell apoptosis. Motility was also significantly increased after acute acid stress. Interestingly, neither secreted nor periplasmic levels of Shiga toxin were affected by acid shock. Pretreatment of bacteria with erythromycin eliminated the acid-induced adhesion enhancement, suggesting that de novo protein synthesis was required for the enhanced adhesion of acid-shocked organisms. DNA microarray was used to analyse the transcriptome of an EHEC O157 : H7 strain exposed to three different acid-stress treatments. Expression profiles of acid-stressed EHEC revealed significant changes in virulence factors associated with adhesion, motility and type III secretion. These results document profound changes in the virulence properties of EHEC O157 : H7 after acid stress, provide a comprehensive genetic analysis to substantiate these changes and suggest strategies that this pathogen may use during gastric passage and colonization in the human gastrointestinal tract.

Objective: Lower-extremity diabetic ulcers (LEDUs) affect more than 500,000 U.S. Medicare beneficiaries each year. Dehydrated human amnionic and chorionic allografts (DHACAs) are clinically effective complements to standard of care (SoC; e.g., surgical debridement, offloading, infection, and moisture control) when treating LEDUs. However, Medicare and commercial payer coverage have restricted access to DHACAs. Our objective was to compare the effectiveness of DHACAs versus SoC among Medicare beneficiaries with LEDUs for reduction of adverse outcomes such as mortality, recurrency, and major amputation. Approach: We analyzed a retrospective cohort of U.S. Medicare claims for LEDUs between 2018 and 2022. LEDU claims were collapsed into episodes of care (EOC). Frequency distribution of characteristics was compared using univariate and bivariate statistics. Zero-inflated binomial regression with 1:1 nearest-neighbor propensity score matching evaluated six main outcome measures: mortality; wound recurrence; major amputation; minor amputation; emergency department (ED) utilization; and readmission. Results: There were 25,760 Medicare EOCs between 2018 and 2022 representing 12,880 matched samples in the DHACA and SoC cohorts. DHACAs were associated with a 20% reduction in 30-day mortality (95% confidence interval [CI]:10%, 29%), 28% reduction in risk of major amputation (95% CI: 19%, 36%), 9% reduction in ED utilization (95% CI: 3%,14%), and 8% reduction in 30-day readmission (95% CI: 2%, 13%). DHACAs were noninferior for minor amputation rates and wound recurrence compared to SoC cohort. Conclusion: Beneficiaries with LEDUs benefit significantly from DHACAs on multiple outcomes, including a lower risk of mortality. Providers should examine the appropriateness of DHACAs for patients with LEDU as part of wound management. Medicare and commercial payers should consider improved outcomes when defining coverage policies that restrict access to DHACAs given the observed benefits.

Background: Antithrombotic drugs, including the P2Y 12 inhibitor ticagrelor, increase the risk of perioperative bleeding in patients requiring urgent cardiac surgery. Perioperative bleeding can lead to increased mortality and prolong intensive care unit and hospital stays. A novel sorbent-filled hemoperfusion cartridge that intraoperatively removes ticagrelor via hemoadsorption can reduce the risk of perioperative bleeding. We estimated the cost-effectiveness and budget impact of using this device versus standard practices to reduce the risk of perioperative bleeding during and after coronary artery bypass grafting from the US healthcare sector perspective., Methods: We used a Markov model to analyze the cost-effectiveness and budget impact of the hemoadsorption device in three cohorts: (1) surgery within 1 day from last ticagrelor dose; (2) surgery between 1 and 2 days from last ticagrelor dose; and (3) a combined cohort. The model analyzed costs and quality-adjusted life years (QALYs). Results were interpreted as both incremental cost-effectiveness ratios and net monetary benefits (NMBs) at a cost-effectiveness threshold of $100,000/QALY. We analyzed parameter uncertainty using deterministic and probabilistic sensitivity analyses., Results: The hemoadsorption device was dominant for each cohort. Patients with less than 1 day of washout in the device arm gained 0.017 QALYs at a savings of $1748 (USD), for an NMB of $3434. In patients with 1-2 days of washout, the device arm yielded 0.014 QALYs and a cost savings of $151, for an NMB of $1575. In the combined cohort, device gained 0.016 QALYs and a savings of $950 for an NMB of $2505. Per-member-per-month cost savings associated with device was estimated to be $0.02 for a one-million-member health plan., Conclusion: This model found the hemoadsorption device to provide better clinical and economic outcomes compared with the standard of care in patients who required surgery within 2 days of ticagrelor discontinuation. Given the increasing use of ticagrelor in patients with acute coronary syndrome, incorporating this novel device may represent an important part of any bundle to save costs and reduce harm., (© 2023. The Author(s).)

Aims: The Novel Coronavirus (COVID-19) has infected over two hundred million worldwide and caused 4.4 million of deaths as of August 2021. Vaccines were quickly developed to address the pandemic. We sought to analyze the cost-effectiveness and budget impact of a non-specified vaccine for COVID-19., Materials and Methods: We constructed a Markov model of COVID-19 infections using a susceptible-exposed-infected-recovered structure over a 1-year time horizon from a U.S. healthcare sector perspective. The model consisted of two arms: do nothing and COVID-19 vaccine. Hospitalization and mortality rates were calibrated to U.S. COVID-19 reports as of November 2020. We performed economic calculations of costs in 2020 U.S. dollars and effectiveness in units of quality-adjusted life years (QALYs) to measure the budget impact and incremental cost-effectiveness at a $100,000/QALY threshold., Results: Vaccines have a high probability of reducing healthcare costs and increasing QALYs compared to doing nothing. Simulations showed reductions in hospital days and mortality by more than 50%. Even though this represents a major U.S. investment, the budget impacts of these technologies could save program costs by up to 60% or more if uptake is high., Limitations: The economic evaluation draws on the reported values of the clinical benefits of COVID-19 vaccines, although we do not currently have long-term conclusive data about COVID-19 vaccine efficacies., Conclusions: Spending on vaccines to mitigate COVID-19 infections offer high-value potential that society should consider. Unusually high uptake in vaccines in a short amount of time could result in unprecedented budget impacts to government and commercial payers. Governments should focus on expanding health system infrastructure and subsidizing payer coverage to deliver these vaccines efficiently.

Importance: The US opioid epidemic is complex and dynamic, yet relatively little is known regarding its likely future impact and the potential mitigating impact of interventions to address it., Objective: To estimate the future burden of the opioid epidemic and the potential of interventions to address the burden., Design, Setting, and Participants: A decision analytic dynamic Markov model was calibrated using 2010-2018 data from the National Survey on Drug Use and Health, Centers for Disease Control and Prevention, National Health and Nutrition Examination Survey, the US Census, and National Epidemiologic Survey on Alcohol and Related Conditions-III. Data on individuals 12 years or older from the US general population or with prescription opioid medical use; prescription opioid nonmedical use; heroin use; prescription, heroin, or combined prescription and heroin opioid use disorder (OUD); 1 of 7 treatment categories; or nonfatal or fatal overdose were examined. The model was designed to project fatal opioid overdoses between 2020 and 2029., Exposures: The model projected prescribing reductions (5% annually), naloxone distribution (assumed 5% reduction in case-fatality), and treatment expansion (assumed 35% increase in uptake annually for 4 years and 50% relapse reduction), with each compared vs status quo., Main Outcomes and Measures: Projected 10-year overdose deaths and prevalence of OUD., Results: Under status quo, 484 429 (95% confidence band, 390 543-576 631) individuals were projected to experience fatal opioid overdose between 2020 and 2029. Projected decreases in deaths were 0.3% with prescribing reductions, 15.4% with naloxone distribution, and 25.3% with treatment expansion; when combined, these interventions were associated with 179 151 fewer overdose deaths (37.0%) over 10 years. Interventions had a smaller association with the prevalence of OUD; for example, the combined intervention was estimated to reduce OUD prevalence by 27.5%, from 2.47 million in 2019 to 1.79 million in 2029. Model projections were most sensitive to assumptions regarding future rates of fatal and nonfatal overdose., Conclusions and Relevance: The findings of this study suggest that the opioid epidemic is likely to continue to cause tens of thousands of deaths annually over the next decade. Aggressive deployment of evidence-based interventions may reduce deaths by at least a third but will likely have less impact for the number of people with OUD.

Aims: To assess incremental charges of patients experiencing venous thromboembolisms (VTE) across various types of elective inpatient surgical procedures with administration of general anesthesia in the US., Methods: The authors performed a retrospective study utilizing data from a nationwide hospital operational records database from July 2014 through June 2015 to compare a group of inpatients experiencing a VTE event post-operatively to a propensity score matched group of inpatients who did not experience a VTE. Patients included in the analysis had a hospital admission for an elective inpatient surgical procedure with the use of general anesthesia. Procedures of the heart, brain, lungs, and obstetrical procedures were excluded, as these procedures often require a scheduled ICU stay post-operatively. Outcomes examined included VTE events during hospitalization, length of stay, unscheduled ICU transfers, number of days spent in the ICU if transferred, 3- and 30-day re-admissions, and total hospital charges incurred., Results: The study included 17,727 patients undergoing elective inpatient surgical procedures. Of these, 36 patients who experienced a VTE event were matched to 108 patients who did not. VTE events occurred in 0.2% of the study population, with most events occurring for patients undergoing total knee replacement. VTE patients had a mean total hospital charge of $60,814 vs $48,325 for non-VTE patients, resulting in a mean incremental charge of $11,979 (p < .05). Compared to non-VTE patients, VTE patients had longer length of stay (5.9 days vs 3.7 days, p < .001), experienced a higher rate of 3-day re-admissions (3 vs 0 patients) and 30-day re-admissions (7 vs 2 patients)., Conclusions: Patients undergoing elective inpatient surgical procedures with general anesthesia who had a VTE event during their primary hospitalization had a significantly longer length of stay and significantly higher total hospital charges than comparable patients without a VTE event.

Background: Biosimilars are of growing clinical, regulatory, and commercial importance., Purpose: To summarize evidence about the bioequivalence between biosimilar and reference tumor necrosis factor-α (TNF-α) inhibitors., Data Sources: PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and LILACS from inception through 13 April 2016 and ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, EU Clinical Trials Register, U.S. Food and Drug Administration, and European Medicines Agency from inception through 30 April 2016., Study Selection: Published English-language studies of any size or design that compared the pharmacokinetics, clinical efficacy, adverse events, or immunogenicity of a biosimilar TNF-α inhibitor with a reference biologic in humans., Data Extraction: Two reviewers independently screened titles and abstracts, extracted data from selected studies, and assessed study quality., Data Synthesis: Of 19 eligible studies, 8 were phase 1 randomized trials, 5 were phase 3 randomized trials, and 6 were observational studies. Most phase 1 trials (n = 7) involved healthy volunteers, phase 3 trials involved patients with rheumatoid arthritis, and observational studies involved those with rheumatoid arthritis or inflammatory bowel disease. All phase 1 trials showed that pharmacokinetic parameters of the biosimilar and respective biologic were within the prespecified equivalence margin of 80% to 125%. Phase 3 trials suggested similar clinical responses and adverse events. Adverse events were usually of mild to moderate severity. Two cross-sectional observational studies showed cross-reactivity between products, whereas 4 cohort studies of patients switched from reference to biosimilar products suggested similar efficacy and safety outcomes., Limitation: Possible publication bias, small sample sizes of many studies, and lack of published studies for several biosimilars., Conclusion: Preliminary evidence supports the biosimilarity and interchangeability of biosimilar and reference TNF-α inhibitors., Primary Funding Source: Johns Hopkins Center of Excellence in Regulatory Science and Innovation. (PROSPERO: CRD42015025262).

Enterohaemorrhagic Escherichia coli (EHEC) survives exposure to acute acid stress during gastric passage and progresses to colonize the large intestine. We previously reported that acid stress significantly increases host adhesion of EHEC O157 : H7 and is associated with a coincident upregulation of the expression of a putative adhesin gene, yadK. Further gene expression analysis now confirms that yadK is minimally transcribed under unstressed conditions and is significantly upregulated under acid stress. Immunoblotting with an anti-YadK polyclonal antiserum demonstrates that YadK protein is also upregulated after acid stress. Disruption of yadK results in loss of the acid-induced adhesion increase seen for wild-type EHEC to human epithelial cells in vitro and complementation in trans fully restores the acid-induced adhesion phenotype to the wild-type level. Significantly, no difference is observed in adhesion of the unstressed yadK mutant relative to wild-type, indicating that YadK does not play a role in adhesion of unstressed EHEC. Anti-YadK antiserum inhibits the acid-induced adhesion enhancement of EHEC but has no effect on adhesion of unstressed EHEC. There is no significant difference in the viability of either the unstressed or the acid-stressed yadK mutant relative to the similarly treated wild-type, suggesting that yadK is not involved in acid tolerance. These results provide persuasive evidence that YadK plays a significant role in the adhesion of acid-stressed EHEC to epithelial cells, and support a role for acid stress as a factor which may regulate bacteria-host attachment and lead to increased EHEC colonization and virulence.