Assessing the role of sow parity on PRRSv detection by RT-qPCR through weekly processing fluids monitoring in breeding herds

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datacite.alternateIdentifier.citationPREVENTIVE VETERINARY MEDICINE,Vol.213,,2023
datacite.alternateIdentifier.doi10.1016/j.prevetmed.2023.105854
datacite.creatorSanhueza, Juan Manuel
datacite.creatorSchwartz, Mark
datacite.creatorCorzo, Cesar A.
datacite.creatorKikuti, Mariana
datacite.creatorYeske, Paul
datacite.creatorLeuwerke, Brad
datacite.creatorSchelkopf, Adam
datacite.creatorWilliams, Todd
datacite.creatorFeuerbach, Steven
datacite.creatorJohnson, Clayton
datacite.creatorToohill, Elise
datacite.creatorTapia Escarate, Daniela
datacite.creatorYang, My
datacite.creatorSchroeder, Declan
datacite.creatorVilalta, Carles
datacite.date2023
datacite.subject.englishPRRS
datacite.subject.englishProcessing fluids
datacite.subject.englishMonitoring
datacite.subject.englishBreeding herd
datacite.subject.englishSwine
datacite.subject.englishParity
datacite.subject.englishSow
datacite.titleAssessing the role of sow parity on PRRSv detection by RT-qPCR through weekly processing fluids monitoring in breeding herds
dc.date.accessioned2023-06-08T15:48:17Z
dc.date.available2023-06-08T15:48:17Z
dc.description.abstractThe use of processing fluids to monitor the breeding herd's porcine reproductive and respiratory syndrome (PRRS) status has gained industry acceptance. However, little is known about PRRS virus RT-qPCR detection dynamics in processing fluids and factors that may contribute to maintain PRRS virus in the herd after an outbreak. This study aimed to describe weekly RT-qPCR processing fluid results in breeding herds after an outbreak and to evaluate the proportion of RT-qPCR positive results among parity groups. Processing tissues of 15 first parity (P1), 15 second parity (P2), and 15 third parity or higher (P3+) litters (parity groups) were collected weekly for between 19 and 46 weeks in nine breeding herds. Processing fluids were aggregated, and RT-qPCR tested by parity group weekly. Additionally, a subset of 743 processing fluid samples of litters that formed 50 parity groups, as previously described, were RT-qPCR tested individually at the litter level. The agreement between RT-qPCR results of processing fluid samples of parity groups (15 litters) and results based on individual litter testing was assessed using overall percent of agreement, Kappa statistic, and McNemar test. The association between RT-qPCR results and the parity group was evaluated using a generalized estimating equa-tions model, after accounting for the effects of sampling week, breeding herd PRRS control strategy (i.e., open to replacements v/s closed) and herd. An autoregressive correlation structure was used to account for the repeated samplings within a herd in time. The overall agreement was 98 %, and Kappa statistic 0.955 (McNemar p = 1.0). Sensitivity of parity group processing fluid samples was estimated at 100 % (95 % CI 89-100 %), while specificity was estimated at 94 % (95 % CI 71-100 %). Although P1 aggregated litters had on average a higher proportion of RT-qPCR positive results from outbreak week 25 onwards, the proportion was not significantly different to the one observed for P2 and P3+ aggregated litters (p > 0.13). Additionally, herds that interrupted gilt entry had lower odds of PRRS RT-qPCR positivity than herds that continued entering gilts (OR = 0.35, 95 % CI 0.16-0.78). PRRS virus persistence in processing fluids was not affected by the sow parity effect in most of the breeding herds studied. No evidence of disagreement between RT-qPCR results of an aggregated sample of 15 litters and those of individual litters was observed. This level of litter aggregation testing strategy may be of particular use at the last stages of an elimination program under low PRRS virus prevalence.
dc.identifier.urihttps://repositoriodigital.uct.cl/handle/10925/5331
dc.language.isoen
dc.publisherELSEVIER
dc.sourcePREVENTIVE VETERINARY MEDICINE
oaire.resourceTypeWOS
oaire.resourceType.enArticle
uct.indizacionSCI
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