Antimicrobial use and antimicrobial resistance monitoring in pig production in the United States of America

Monitoring antimicrobial use (AMU) and antimicrobial resistance (AMR) on farms is recognised as an important component of antimicrobial stewardship, yet the process can be resource intensive. This paper describes a subset of findings from the first year of a collaboration across government, academia and a private sector veterinary practice focused on swine production in the Midwestern United States. The work is supported by participating farmers and the greater swine industry. Twice-annual collection of samples from pigs along with AMU monitoring occurred on 138 swine farms. Detection and resistance of Escherichia coli from pig tissues was assessed, and associations between AMU and AMR were evaluated. This paper describes the methods utilised and the first-year E. coli-related results from this project. Higher minimum inhibitory concentrations (MIC) for enrofloxacin and danofloxacin in E. coli from swine tissues were associated with the purchase of fluoroquinolones. There were no other significant associations between MIC and AMU combinations in E. coli isolated from pig tissues. This project represents one of the first attempts to monitor AMU as well as AMR in E. coli in a large-scale commercial swine system in the United States of America.

The Use of Facial Anthropometrics in Aesthetic Assessment

Objective

To identify a valid method for scoring facial aesthetics, correlating clinicians' assessments with measurements taken from 3D facial photographs.

Design

Album assessment of facial images, using a visual analog scale of attractiveness and the scores ranked. Facial ratios, obtained following digitization of the images compared with control group mean data, obtained from the Farkas growth study and the differences from the matched mean calculated. Ranked scores compared according to the inclusion of surface as well as caliper (shortest distance) measurements and whether the ranked scores, representing difference to the mean, were weighted.

Patients, Participants

Eleven facial images were presented. Seven clinicians provided clinical judgment.

Main Outcome Measures

Correlation coefficients between mean attractiveness rankings and summed differences between patients' facial proportions and matched control data from the Farkas growth study.

Results

The highest correlation was obtained with the use of the difference accommodating the mean of the Farkas proportion index ( r  =  −.76, p  =  .006), followed by standard deviation ( r  =  −.65, p  =  .032), using data in which the difference is weighted according to the magnitude of the linear measurement involved. Repeatability of the clinicians' assessments and operator digitization were validated.

Conclusions

There appears to be potential in the use of the mean as aesthetic ideal as a principle in aesthetic assessment and perhaps as an objective means of outcome assessment after facial surgery. The most appropriate scoring method would seem to include use of both surface and caliper measurements and incorporate weighting.

Efficacy of immunising pigs against porcine circovirus type 2 at three or six weeks of age

The efficacy of a porcine circovirus type 2 (pcv-2) vaccine was tested in pigs vaccinated at three or six weeks of age. A total of 1106 weaned pigs were randomly allocated to one of three treatment groups: vaccinated at three weeks of age, vaccinated at six weeks of age, or not vaccinated. Each pig was weighed at three, 10 and 22 weeks of age, and 48 pigs selected at random from each treatment group were serially blood sampled at three, six, 10, 14, 18 and 22 weeks of age. The mean weight of the vaccinated pigs was 6.1 kg heavier at 22 weeks than the unvaccinated pigs. The combined mortality and cull rates of the unvaccinated pigs during the growing/finishing period was 14.1 per cent compared with 3.6 per cent and 3.1 per cent for the pigs vaccinated at three weeks and six weeks, respectively. The vaccinated pigs also had a significantly higher mean daily weight gain and a smaller load of humoral pcv-2 than the unvaccinated pigs.

Comparison of three methods of facial measurement

The aims of this study were to assess the accuracy of measurements recorded by 3D stereophotogrammetry and to compare three methods of facial measurement: manual anthropometry, 3D stereophotogrammetry and 2D photography. Measurements were taken from 14 landmarks on each of six volunteers and compared. In addition, the variability of the methods was assessed. Three-dimensional measurements were shown to compare well with manual measurements on volunteers as well as test objects for which the mean difference was 0.23 mm (shortest distance) and 0.13 mm (surface). All the three methods of measurement were found to have good levels of repeatability. Two-dimensional measurements were more variable than manual measurements (P=0.021). Three-dimensional stereophotogrammetric measurements were shown to compare well with manual measurements although the values obtained were mostly slightly larger. Stereophotogrammetry allows images to be taken in a Medical Photography Department, facilitating the accurate measurement of facial morphology from digitized data, including changes associated with treatment or growth. There are clear potential benefits of using 3D measurements in the assessment of facial deformity.

Clinical and computerized assessment of mandibular asymmetry

The aim of this study was to investigate assessment of mandibular asymmetry by clinicians and to evaluate a new computerized system. Eight experienced clinicians (four maxillofacial surgeons and four orthodontists) assessed 12 standardized facial photographs of patients selected to provide a range, from normality to marked mandibular asymmetry. Photographs were taken under standardized conditions; analysis of photographs repeated after one month showed close agreement. The computerized system used four different methods for quantifying asymmetry based on right/left differences in perimeter, area, compactness, and centre of area ratios. Good agreement (kappa = 0.77) was achieved by the clinicians in assessing the likelihood of treatment need; however, when assessing an 'acceptable' level of asymmetry, agreement was moderate (kappa = 0.46). Differences in perimeter ratios did not compare well with clinical assessment, but those for both area and compactness showed 100 per cent sensitivity and specificity to clinical assessment at ratio differences of 0.05 and 0.03 (deviation from 1), respectively. A centre of area difference ratio greater than 1 showed 75 per cent sensitivity and 85 per cent specificity to clinical assessment. These parameters could prove useful in quantifying change in asymmetries brought about by growth, treatment, or any subsequent relapse.

The use of vacuum-formed splints for temporary intermaxillary fixation in the management of unilateral condylar fractures

We report a simple, effective method of managing displaced unilateral condylar fractures with occlusal disruption using vacuum-formed thermoplastic foil splints with bonded wire cleats. The cleats enable intermaxillary fixation in the form of orthodontic elastics to be used, which guide then maintain the occlusion in centric relation. A case is presented in which this technique was used successfully.

Long-term stability of the lower labial segment relative to the A-Pog line

Cephalometric records of 47 cases treated with the Begg technique were examined with a view to assessing both the effects of treatment and long-term change. The cases were treated by a single operator (Dr H. Brouwer) whose long-term records were taken on average over 10 years out of retention. Special reference was made of the use of A-Pog line as a guide to lower incisor stability. There was marked individual variation in both response to treatment and long-term change. Though all the results were clinically stable the A-Pog line was not found to be a reliable guide to lower incisor stability. In 62 per cent of the cases examined, the lower incisors tended to return towards their original positions after retention, whilst in the remaining cases the changes were extremely variable.