Comparison of surveys and use records for quantifying medically important antimicrobial use in 18 U.S. Beef Feedyards

The effect of particulate matter 2.5 on seasonal influenza transmission in 1,330 counties, China: A Bayesian spatial analysis based on Köppen Geiger climate zones classifications

Previous research has linked seasonal influenza transmission with particulate matters (PM2.5). However, the effect of PM2.5 on seasonal influenza transmission varied by region. This study aims explore how PM2.5 influenced seasonal influenza transmission in the elderly across 1330 counties in two Köppen Geiger climate zones in China, incorporating the socio-economic factors to enhance climate-driven early warning systems (EWS) for influenza. Data included weekly 2015-2019 influenza cases in those aged >65 from China's national influenza surveillance system for 1330 counties in two Köppen Geiger climate zones: Temperate, Hot Summer with Dry Winter (Cwa) and No Dry Season (Cfa). PM2.5 data from 2015 to 2019 were sourced from Copernicus Atmosphere Monitoring Services. Additional data on floating population, population density and Gross Domestic Product (GDP) per capita were collected from pertinent departments. A Bayesian spatial autoregressive model assessed the association of PM2.5 and influenza transmission after adjustment of socio-economic factors. Our research results showed PM2.5 (per 1 μg/m³ increase) was linked to increased influenza transmission in the Cwa zone during winter season (Relative Risk (RR) = 1.023, 95% Credible Interval (CI):1.008-1.040) but not in the Cfa winter (RR = 1.003, 95% CI: 0.992-1.015). Floating population significantly enhanced transmission in both zones (highest RR = 1.362, 95% CI:1.181-1.583), while GDP per capita growth was associated with reduced transmission risk (highest RR = 0.619, 95% CI: 0.445-0.861). The study identifies PM2.5 as a significant factor influencing influenza transmission in the elderly, with effects varying by climate zone, suggesting the need to incorporate PM2.5 and socio-economic factors into seasonal influenza EWS.

A Scoping Review of Antimicrobial Usage and Antimicrobial Resistance in Beef Cow-Calf Herds in the United States and Canada

BACKGROUND

The magnitude and knowledge gaps regarding antimicrobial use (AMU) and antimicrobial resistance (AMR) have not been summarized for the North American cow-calf production sector, although estimates of AMU and AMR are essential to AMR risk analysis. The objectives of this scoping review were to map AMU and AMR in the beef cow-calf sector in Canada and the United States, summarize published AMU/AMR predictors, and identify research gaps.

METHODS

An electronic search was conducted of four bibliographic databases and Google Scholar, augmented by a hand-search of captured studies.

RESULTS

Twenty-three of three-hundred and forty-three publications screened advanced to data extraction. Of these, 10 were conducted in the USA and 13 in Canada. Thirteen studied AMR and twelve studied AMU, with two reporting both. Of twelve captured AMU studies, nine presented counts of herd AMU by antimicrobial class or specific antimicrobial. Antimicrobial resistance in Escherichia coli (E. coli) was reported in nine studies. Risk factors for AMU include herd size, vaccine use, and start date of calving season.

CONCLUSIONS

Overall, a small number of AMR studies were available for synthesis in primarily one population (cows) reporting E. coli AMR. Additional studies targeting reasons for AMU in calves, the impact of management procedures on AMU, potential environmental AMR sources, and AMR in respiratory pathogens and enteric organisms other than E. coli for pre-weaning calves are required to inform AMR risk mitigation strategies.

Antimicrobial use in 20 U.S. beef feedyards: 2018-2019

The objective of this study was to report antimicrobial use in a convenience sample of U.S. beef feedyards for the years 2018 and 2019. In addition to antimicrobial use metrics, also reported are the indications for antimicrobial use and outcomes related to these indications. Antimicrobial use is characterized at the study and feedyard levels for a total of 1,141,846 head of cattle in 20 U.S. feedyards. Antimicrobial use is reported as milligrams of active antimicrobial ingredient per kilogram of liveweight sold (mg/kg-LW) and regimens of antimicrobials per animal year (Reg/AY). Regimens are described by antimicrobial class within use category as characterized by mg of active antimicrobial product per regimen (mg/Reg) and calendar days of administration per regimen (CDoA/Reg). A total of 1,128,515 regimens of medically important antimicrobials were captured from records. The number of regimens/100 head-in (Reg/100 head-in) are described in a subset of 10 feedyards with adequate data granularity to directly determine indications for antimicrobial administration. For the indications of bovine respiratory disease (BRD), Lameness (Lame), Liver Abscess Control (LAC), and Other (e.g., central nervous system disease, cellulitis) the Reg/100 head-in study-level values are 37.1, 0.8, 98.4, and 0.7, respectively, for 2018, with similar values for 2019. The regimens for BRD are further categorized in these 10 feedyards by the use categories in-feed, control of BRD, and individual animal therapy, yielding study level values of 4.6, 19.6, and 12.9 Reg/100 head-in, respectively, for 2018, with similar values for 2019. Outcomes of therapy for individual animal treatment of BRD, Lame, and Other are reported as treatment success, retreatment, or mortality by 30 days after the initial therapy of an animal for a disease. Treatment success rates (no treatment or mortality in the next 30 days) for 2018 in the 10 feedyards with sufficient data granularity are 76.5, 86.5, and 83.0% for BRD, Lame, and Other, respectively. The comparison of these results with other reports of antimicrobial use in North American feedyards highlights how differing approaches in calculating metric values may result in substantially different conclusions regarding antimicrobial use, especially in relation to long-duration uses.

Evaluation of the use of antibiotic waste bins and medicine records to quantify antibiotic use on sheep, beef, and mixed species farms: A mixed methods study

There is a lack of robust data on antibiotic use on sheep and beef farms in the UK, particularly for farms with mixed species. On mixed farms, quantification of antibiotic use is reliant on accurate farmers' records as veterinary prescription data does not provide information at the species level. Previous studies that have investigated multiple antibiotic use collection methods were conducted on single species farms and failed to collect data on the reasons why differences in methods may exist. This study aimed to evaluate sheep and beef farmers' antibiotic recording practices by comparing quantities of antibiotics measured from medicine records and empty antibiotic packaging collection bins, and identify barriers and facilitators of the antibiotic use collection methods. Thirty-five farms were followed for a year period. Farmers were asked to record their antibiotic treatments and deposit empty antibiotic packaging used in sheep or beef cattle into a bin. Semi-structured qualitative interviews were conducted to understand the experiences of farmers taking part in the study and explore the possible differences in methods. Bins and medicine records were collected and the mass of active ingredient (mg) was calculated. The level of agreement between the two antibiotic use collection methods was measured using rank parameters of Kendall's T_a. The bins were 67 % (CI = 29-87 %) more likely to measure more antibiotic use than the medicine records. The scale of variability of the measurements between two random farms was 33 % (CI = 6-56 %) larger for the antibiotic waste bins than the scale of variability between the medicine records. Sheep farmers often missed neonatal lamb treatments off their medicine records, with a median of 32.5 missing treatments per farm (IQR = 18-130). Of the mixed species farms, 28 % of treatment entries were missing the species the antibiotic was used in. Farmers reported that the bin was easy to use but they also reported that there was a tendency to under-report actual use where there were multiple workers on the farm or where treatments were administered by the veterinarian. The qualitative analysis identified contextual barriers to accurate medicine recording, such as difficulties with animal identification, with recording in the field, and with recording during lambing time. This study demonstrated that there were significant differences in antibiotic use measured by the bins and the medicine records. The mixed-methods approach provided an understanding of the contextual barriers that impacted farmers' medicine recording and use of the bin. This information on the contextual barriers can be used to inform the design of data collection methods to improve antibiotic consumption data in the sheep and beef sectors.

Assessment of Antibiotic Stewardship Components of Certification Programs in US Animal Agriculture Using the Antibiotic Stewardship Assessment Tool

Antibiotic stewardship programs (ASPs) are meant to promote appropriate use of antibiotics and to help maintain the effectiveness of antibiotics. For the United States (US) animal agriculture industry, multiple resources exist to guide antibiotic stewardship practices. Animal management certification programs can promote on-farm compliance with antibiotic stewardship through the incentive of achieving certification. The goal of this project was to determine whether the stewardship-related requirements of US-based certification programs align with identified core components of antibiotic stewardship in food animal agriculture using the Antibiotic Stewardship Assessment Tool (ASAT). We applied the ASAT to publicly available information from four different US animal agriculture certification programs that incorporate some level of antibiotic stewardship. In part due to varying scopes, the programs demonstrated a great deal of variability in meeting the metrics of the ASAT, with one program meeting all the required metrics and the other three only meeting the metrics to varying degrees (ranging from 3 to 67%). We identified several areas as opportunities for enhancing and promoting ASP implementation on farms. The area with the most opportunity for improvement is evaluation. Evaluation can help ensure effective outcomes of stewardship practices and ensure accountability for following recommended antibiotic stewardship guidelines. While evaluation currently may fall outside the scope of some certification programs, the incorporation of more specific antibiotic stewardship evaluation details within certification program content could serve as an important mechanism for promoting voluntary on-farm compliance with antibiotic stewardship guidelines.

Antimicrobial use in 22 U.S. beef feedyards: 2016-2017

This study describes antimicrobial use in 22 U.S. beef feedyards by use of two metrics: milligrams of antimicrobial per kilogram of liveweight sold (mg/kg-LW) and antimicrobial regimens per animal year (Reg/AY). The primary objectives were to determine the feasibility of collecting antimicrobial use data at the level of the production system and to identify factors unique to feedyard systems which may confound interpretation of summarized antimicrobial use measures. Records were accessed directly from feedyards or through a data intermediary and then subjected to a process of standardization and quality assurance. Use is reported at the study level with all individual cattle lots from all feedyards combined, as well as at the feedyard level where values were first calculated for each feedyard and then expressed as means, standard deviations and median values. Use at the study level is first reported by antimicrobial class and then by antimicrobial class within the use categories of in-feed, control of bovine respiratory disease (BRD) and individual animal treatment. Due to wide variations of antimicrobial class within use category, feedyard level antimicrobial use is reported only by antimicrobial class. Use values for medically important and not medically important antimicrobial classes are reported separately. Regimens are described for each antimicrobial class within use category by milligrams per regimen and by timeframe from first to last administration. The authors' selection of measures reported here was driven by a desire to minimize necessary assumptions, resulting in transparent reporting of values which can be directly related back to the factors within feedyard systems which may have influenced calculations. Reporting the number of regimens stratified by antimicrobial class within use category and then describing the characteristics of the reported regimens (milligrams per regimen and timeframe) optimize these objectives for reporting.