Field application of a commercial porcine reproductive and respiratory syndrome virus (PRRSV) oral fluid antibody enzyme-linked immunosorbent assay (ELISA).

A commercial porcine reproductive and respiratory syndrome virus (PRRSV) oral fluid antibody enzyme-linked immunosorbent assay (ELISA) was used on 31 commercial swine farms in Ontario using oral fluid samples (~6 per herd) collected from cotton ropes. Using the manufacturer's cutoff [sample-to-positive ratio (S/P) ≥ 0.4], 2 of 135 oral fluid samples from 23 PRRSV presumed negative herds tested positive (1.5% false positive rate). Three approaches to improving test diagnostic specificity were compared: i) use a cutoff of S/P ≥ 0.8 for individual oral fluid samples; ii) use the current cutoff of S/P ≥ 0.4 but use a mean S/P based on several oral fluid samples (6 samples were used in this study); and iii) use serial testing to resolve unexpected positive ELISA results, i.e., retest using a reverse transcription-polymerase chain reaction (RT-PCR) to determine whether low positive S/P ratios are the result of early PRRSV infection in a barn.

Application sur le terrain d'une épreuve immuno-enzymatique (ELISA) commerciale pour détecter des anticorps contre le virus du syndrome reproducteur et respiratoire porcin en utilisant des fluides oraux. Une épreuve immuno-enzymatique (ELISA) commerciale pour détecter des anticorps contre le virus du syndrome reproducteur et respiratoire porcin (VSRRP) en utilisant des fluides oraux fut utilisée sur 31 fermes commerciales en Ontario en utilisant des échantillons de fluides oraux (~6 par troupeau) prélevés en utilisant des cordes en coton. En utilisant le seuil recommandé par le manufacturier [ratio échantillon-à-positif (S/P) ≥ 0,4], 2 des 135 échantillons de fluides oraux provenant de 23 troupeaux présumés négatifs pour le VSRRP ont testé positif (taux de faux positifs de 1,5 %). Trois approches pour améliorer la spécificité du test furent comparées: i) utilisation d'une valeur seuil de S/P ≥ 0,8 pour les échantillons de fluides oraux individuels; ii) utilisant de la valeur seuil actuelle S/P ≥ 0,4 mais utiliser une S/P moyenne basée sur plusieurs échantillons de fluides oraux (6 échantillons furent utilisés dans la présente étude); et iii) utiliser des tests en série pour résoudre les résultats ELISA positifs non-attendus; retester en utilisant la réaction d'amplification en chaine par la polymérase avec la transcriptase reverse (RT-PCR) afin de déterminer si les ratios S/P faiblement positifs sont le résultat d'une infection débutante dans une ferme.(Traduit par Dr Serge Messier).

Age related differences in mechanical demands imposed on the lower back by manual material handling tasks.

The prevalence of low back pain (LBP) increases with age, yet the underlying mechanism(s) responsible for this remains unclear. To explore the role of biomechanical factors, we investigated age-related differences in lower-back biomechanics during sagittally-symmetric simulated manual material handling tasks. For each task, trunk kinematics and mechanical demand on the lower back were examined, from among 60 participants within five equal-sized and gender-balanced age groups spanning from 20 to 70 years old. The tasks involved lowering a 4.5 kg load from an upright standing posture to both knee height and a fixed height and then lifting the load back to the initial upright posture. During these tasks, segmental body kinematics and ground reaction forces were collected using wireless inertial measurement units and a force platform. Overall, older participants completed the tasks with larger pelvic rotation and smaller lumbar flexion. Such adopted trunk kinematics resulted in larger peak shearing demand at the lower back in older vs. younger participants. These results suggest that older individuals may be at a higher risk for developing lower back pain when completing similar manual material handling tasks, consistent with epidemiological evidence for higher risks of occupational low back pain among this cohort.

Information about tests for breast cancer: what are we telling people?

We reviewed publications currently available about breast cancer screening to assess what information was provided about test accuracy and pretest and posttest disease probabilities, as this information is needed by consumers to make informed decisions about whether to undergo testing and to fully understand test results. A rating form was developed and used to assess 54 publications about their reports of breast cancer tests. A description of how the test is done was provided by almost all publications (93%). About half (48%) provided some information about possible adverse effects of the test. Eighteen percent of publications provided some (generally qualitative) information about test accuracy, and none provided quantitative information about the probability of disease given normal and abnormal test results.