Multi-Institutional Validation of a Mammography-Based Breast Cancer Risk Model.

PURPOSE: Accurate risk assessment is essential for the success of population screening programs in breast cancer. Models with high sensitivity and specificity would enable programs to target more elaborate screening efforts to high-risk populations, while minimizing overtreatment for the rest. Artificial intelligence (AI)-based risk models have demonstrated a significant advance over risk models used today in clinical practice. However, the responsible deployment of novel AI requires careful validation across diverse populations. To this end, we validate our AI-based model, Mirai, across globally diverse screening populations. METHODS: We collected screening mammograms and pathology-confirmed breast cancer outcomes from Massachusetts General Hospital, USA; Novant, USA; Emory, USA; Maccabi-Assuta, Israel; Karolinska, Sweden; Chang Gung Memorial Hospital, Taiwan; and Barretos, Brazil. We evaluated Uno's concordance index for Mirai in predicting risk of breast cancer at one to five years from the mammogram. RESULTS: A total of 128,793 mammograms from 62,185 patients were collected across the seven sites, of which 3,815 were followed by a cancer diagnosis within 5 years. Mirai obtained concordance indices of 0.75 (95% CI, 0.72 to 0.78), 0.75 (95% CI, 0.70 to 0.80), 0.77 (95% CI, 0.75 to 0.79), 0.77 (95% CI, 0.73 to 0.81), 0.81 (95% CI, 0.79 to 0.82), 0.79 (95% CI, 0.76 to 0.83), and 0.84 (95% CI, 0.81 to 0.88) at Massachusetts General Hospital, Novant, Emory, Maccabi-Assuta, Karolinska, Chang Gung Memorial Hospital, and Barretos, respectively. CONCLUSION: Mirai, a mammography-based risk model, maintained its accuracy across globally diverse test sets from seven hospitals across five countries. This is the broadest validation to date of an AI-based breast cancer model and suggests that the technology can offer broad and equitable improvements in care.

Estimating the Rates of Acquisition and loss of Resistance of Enterobacteriaceae to Antimicrobial Drugs in Pre-Weaned Dairy Calves.

The objective of this study was to investigate the effect of the antimicrobial drugs (AMD) on the shedding of resistant Enterobacteriaceae in feces of pre-weaned dairy calves. The AMD considered were ceftiofur, administered parenterally, and neomycin sulfate added in milk replacer and fed to calves during the first 20 days of life. Fifty-five calves, aged one to three days, were enrolled and followed to 64 days. Fecal samples were collected three times/week and treatments recorded daily. Enterobacteriaceae were quantified for a subset of 33 calves using spiral plating on plain, ceftiofur supplemented, and neomycin supplemented MacConkey agar. Negative binomial models were used to predict the association between treatment with AMD and the gain and loss of Enterobacteriaceae resistance over time. Acquisition of resistance by the Enterobacteriaceae occurred during treatment and peaked between days three to four post-treatment before decreasing to below treatment levels at days seven to eight post-treatment. Acquisition of neomycin resistance was observed on the first sampling day (day four from the start of feeding medicated milk replacer) to day eight, followed by cyclical peaks until day 29, when the Enterobacteriaceae counts decreased below pre-treatment. Enterobacteriaceae resistance against both AMD increased after AMD administration and didn't return to pre-therapeutic status until seven or more days after therapy had been discontinued. The study findings provide valuable insights into the dynamics of Enterobacteriaceae under routine AMD use in calves.

The Evidence Base for Prevention of Infectious Bovine Keratoconjunctivitis Through Vaccination.

Pili and cytotoxins are important virulence factors and antigens for Moraxella spp. Local and systemic immunity may play a role in the body's response to infectious bovine keratoconjunctivitis (IBK). No evidence exists that eliminating the carrier state for IBK is possible or beneficial. Evidence for efficacious transfer of passive immunity from dams to calves is conflicting. Autogenous vaccines and commercial vaccines for putative pathogens for IBK have not yet shown efficacy in blinded randomized field trials. Study design features, such as randomization, blinding, diagnostic criteria, and use of a placebo, reduce the risk of bias in vaccine studies for IBK.

Epidemiology of antimicrobial resistance (AMR) on California dairies: descriptive and cluster analyses of AMR phenotype of fecal commensal bacteria isolated from adult cows.

BACKGROUND: This study describes the occurrence of antimicrobial resistance (AMR) in commensal Escherichia coli and Enterococcus/Streptococcus spp. (ES) isolated from fecal samples of dairy cows and assesses the variation of AMR profiles across regions and seasons following the implementation of the Food and Agricultural Code (FAC) Sections 14400-14408 (formerly known as Senate Bill, SB 27) in California (CA). METHODS: The study was conducted on ten dairies distributed across CA's three milk sheds: Northern California (NCA), Northern San Joaquin Valley (NSJV), and the Greater Southern California (GSCA). On each study dairy, individual fecal samples were collected from two cohorts of lactating dairy cows during the fall/winter 2018 and spring/summer 2019 seasons. Each cohort comprised of 12 cows per dairy. The fecal samples were collected at enrollment before calving (close-up stage) and then monthly thereafter for four consecutive time points up to 120 days in milk. A total of 2,171 E. coli and 2,158 ES isolates were tested for antimicrobial susceptibility using the broth microdilution method against a select panel of antimicrobials. RESULTS: The E. coli isolates showed high resistance to florfenicol (83.31% ± 0.80) and sulphadimethoxine (32.45%), while resistance to ampicillin (1.10% ± 0.21), ceftiofur (1.93% ± 0.29), danofloxacin (4.01% ± 0.42), enrofloxacin (3.31% ± 0.38), gentamicin (0.32% ± 0.12) and neomycin (1.61% ± 0.27) had low resistance proportions. The ES isolates were highly resistant to tildipirosin (50.18% ± 1.10), tilmicosin (48% ± 1.10), tiamulin (42%) and florfenicol (46% ± 1.10), but were minimally resistant to ampicillin (0.23%) and penicillin (0.20%). Multidrug resistance (MDR) (resistance to at least 1 drug in ≥3 antimicrobial classes) was observed in 14.14% of E. coli isolates and 39% of ES isolates. Escherichia coli isolates recovered during winter showed higher MDR prevalence compared to summer isolates (20.33% vs. 8.04%). A higher prevalence of MDR was observed in NSJV (17.29%) and GSCA (15.34%) compared with NCA (10.10%). CONCLUSIONS: Our findings showed high rates of AMR to several drugs that are not labeled for use in lactating dairy cattle 20 months of age or older. Conversely, very low resistance was observed for drugs labeled for use in adult dairy cows, such as cephalosporins and penicillin. Overall, our findings identified important differences in AMR by antimicrobial class, region and season.

Effect of Antimicrobial Treatment on the Dynamics of Ceftiofur Resistance in Enterobacteriaceae from Adult California Dairy Cows.

Dairy farm use of antimicrobial drugs (AMD) is a risk for the selection of antimicrobial resistance (AMR); however, these resistance dynamics are not fully understood. A cohort study on two dairy farms enrolled 96 cows with their fecal samples collected three times weekly, for the first 60 days in milk. Enterobacteriaceae were enumerated by spiral plating samples onto MacConkey agar impregnated with 0, 1, 8, 16 and 30 µg/mL ceftiofur. Negative binomial regression analyzed AMR over time. The continuum of ceftiofur concentrations permitted estimation of the minimum inhibitory concentration (MIC) and analysis using interval regression. The most common systemic AMD was ceftiofur, administered in 94% of treatments (15/16 cows). Enterobacteriaceae did not grow in 88% of samples collected from non-AMD treated cows at 8 µg/mL ceftiofur. Samples from AMD treated cows had peak counts of resistant Enterobacteriaceae during AMD treatment and returned to baseline counts by 3-4 days post-treatment at 8 µg/mL. Sensitive Enterobacteriaceae (0-1 µg/mL ceftiofur) were reduced below pre-treated levels for 29-35 days post-AMD treatment. Population MIC peaked during AMD treatment and returned to baseline levels by 7-8 days. We conclude that the effect of systemic ceftiofur on the resistance of Enterobacteriaceae in early lactation dairy cows was limited in duration.

Impact of Education and Peer Comparison on Antibiotic Prescribing for Pediatric Respiratory Tract Infections.

INTRODUCTION: Inappropriate prescribing of broad-spectrum antibiotics is a significant modifiable risk factor for the development of antibiotic resistance. The objective was to improve guideline-concordant care for 3 common acute respiratory tract infections (ARTIs) and to reduce broad-spectrum antibiotic prescribing in ambulatory pediatric patients. METHODS: Quality measures were developed for 3 ARTIs: viral upper respiratory infection (URI), acute bacterial sinusitis (ABS), and acute otitis media (AOM). Among 22 pediatric clinics, a collaborative of 10 was identified for intervention using baseline data for each ARTI, and 3 plan-do-study-act cycles were planned and completed. Outcomes included guideline-concordant antibiotic utilization and broad-spectrum antibiotic prescribing percentage (BSAP%). Comparison in number of diagnoses for the ARTI measures and total antibiotic prescribing over time served as balancing measures. RESULTS: Collaborative clinics had baseline medians for appropriate or first-line treatment of 70% for URI, 53% for ABS, and 36% for AOM. To reach targets for URI, ABS, and AOM required 6, 14, and 18 months, respectively. At 42 months, performance for all 3 ARTIs remained ≥90%. BSAP% decreased from a baseline of 57% to 34% at 24 months. There was a limited effect from financial incentives but a significant decrease was noted in total antibiotic utilization. Diagnosis shifting may have occurred for URI and ABS while the rates for diagnoses for AOM declined over time. CONCLUSIONS: Through education and peer comparison feedback, guideline-concordant care for 3 ARTIs in collaborative clinics improved and remained beyond above targets and was accompanied by reductions in BSAP% and total antibiotic prescribing.

Quality of care for secondary prevention for patients with coronary heart disease: results of the Hastening the Effective Application of Research through Technology (HEART) trial.

BACKGROUND: Effective therapies for reducing mortality rates in persons with coronary heart disease (CHD) remain underused. We report the results of an effectiveness trial of a quality improvement effort to increase the use of 3-hydroxy-3methylglutaryl coenzyme A (HMG CoA) reductase inhibitors, beta-blockers, and angiotensin-converting enzyme (ACE) inhibitors in patients with CHD in a network-model managed-care setting. METHODS: Patients with CHD were identified by searching a claims database. The use of therapies was assessed by linkage with a pharmacy database. An intervention, consisting of a guideline summary, peer comparison performance feedback, and patient specific chart reminders was evaluated in a randomized, practice-based effectiveness trial. RESULTS: Data were available for >700 patients per year (1999-2002) in 131 practices. At baseline (1999), 55% of patients were receiving HMG CoA reductase inhibitors, 39% of patients were receiving beta-blockers, and 24% of patients were receiving ACE inhibitors. The use of all 3 types of medications increased steadily with time, with the exception of a decrease in the use of HMG CoA reductase inhibitors in the final year (2002). No difference in medication use was observed between randomized groups. CONCLUSIONS: The observed pattern of care supports the contention that the quality of outpatient care for secondary prevention of CHD improved from 1999 to 2002 in this setting. The basis for the inconsistent pattern of use of HMG CoA reductase inhibitors is not certain, but may relate to concerns about toxicity. Centralized mailings of guideline summaries, performance feedback reports, and chart reminders had no observable impact on quality of care in this setting. More intensive intervention may be required to improve the quality of outpatient care for the secondary prevention of CHD.