By:Lowe, J (Lowe, James); McCann, R (McCann, Ryan) ; Greiner, L (Greiner, Laura)
Volume: 25
Issue: 1
Pages: 19-23
Published: JAN-FEB 2017
Abstract
Objectives: To estimate the impact of environmental conditions and management practices on the likelihood of cross-contamination of a pig transport vehicle with porcine reproductive and respiratory syndrome virus (PRRSV) during market-animal unloading.
Materials and methods: An experimental model was developed to simulate indirect contact involving footwear between an unloading dock and a pig transport vehicle. Two experiments were conducted. Experiment 1 evaluated temperature on the. model 0 trailer (4 degrees C, 15 degrees C, or 28 degrees C) for 60 minutes after contact with the contaminated dock (32 contact replicates per temperature). In Experiment 2, 'conditions on the model dock were evaluated in a 2 x 2 x 2 factorial arrangement with repeated measures. Main effects were temperature (4 degrees C or 32 degrees C), ultraviolet light (ambient or supplemental), and mechanical scraping (de-bulked or not) with four contact events per combination. Samples were collected using a Swiffern (Procter 8c Gamble, Cincinnati, Ohio). All samples were tested for PRRSV using reverse -transcription polymerase chain reaction.
Results: Experiment 1: Temperature did not affect the amount of PRRSV RNA recovered. If PRRSV RNA was detected on the model dock, it was transferred and detected on the model trailer 80% of the time (95% CI, 70.0%-90.0%). Experiment 2: De-bulking resulted in a significant reduction in the likelihood of transfer (odds ratio = 0.14; 95% CI, 0.06-0.32).
Implications: Contact at the harvest plant lairage unloading is a risk factor for PRRSV transmission with inadequate livestock trailer hygiene. This risk can be mitigated through mechanical removal of gross contamination of the dock.
Materials and methods: An experimental model was developed to simulate indirect contact involving footwear between an unloading dock and a pig transport vehicle. Two experiments were conducted. Experiment 1 evaluated temperature on the. model 0 trailer (4 degrees C, 15 degrees C, or 28 degrees C) for 60 minutes after contact with the contaminated dock (32 contact replicates per temperature). In Experiment 2, 'conditions on the model dock were evaluated in a 2 x 2 x 2 factorial arrangement with repeated measures. Main effects were temperature (4 degrees C or 32 degrees C), ultraviolet light (ambient or supplemental), and mechanical scraping (de-bulked or not) with four contact events per combination. Samples were collected using a Swiffern (Procter 8c Gamble, Cincinnati, Ohio). All samples were tested for PRRSV using reverse -transcription polymerase chain reaction.
Results: Experiment 1: Temperature did not affect the amount of PRRSV RNA recovered. If PRRSV RNA was detected on the model dock, it was transferred and detected on the model trailer 80% of the time (95% CI, 70.0%-90.0%). Experiment 2: De-bulking resulted in a significant reduction in the likelihood of transfer (odds ratio = 0.14; 95% CI, 0.06-0.32).
Implications: Contact at the harvest plant lairage unloading is a risk factor for PRRSV transmission with inadequate livestock trailer hygiene. This risk can be mitigated through mechanical removal of gross contamination of the dock.
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