Kobuvirus shedding dynamics in a swine production system and their association with diarrhea

Citation

Nantel-Fortier, N., Lachapelle, V., Letellier, A., L'Homme, Y., Brassard, J. (2019). Kobuvirus shedding dynamics in a swine production system and their association with diarrhea. Veterinary Microbiology, [online] 235 319-326. http://dx.doi.org/10.1016/j.vetmic.2019.07.023

Plain language summary

Porcine kobuvirus is an emerging virus and there are currently very limited data on the prevalence of kobuviruses in Canadian swine herds. The link to diarrhea in pigs has been raised, however, data have not yet been able to confirm its role in the disease. In this study, a total of 181 diarrhea and healthy Canadian piglets were monitored and sampled four times to represent the different stages of production. Piglets were sampled on the suckling farms (birth to weaning), nursery farms (after weaning) and finishing farms (at the beginning and end of fattening). Fecal and environmental samples were collected at each life stage. The virus was subsequently detected and characterized by molecular methods. The results obtained showed that during the last suckling phase (6-21 days), piglets with diarrhea excreted more Kobuvirus than healthy individuals. Moreover, it is during the nursery stage that the virus is most present and nearly 97% of the piglets sampled excreted the virus at least once in their lifetime. This study detected kobuvirus for the first time in the Canadian swine herd and shed light on the dynamics of excretion and their potential role in neonatal diarrhea at the lactation stage.

Abstract

Porcine kobuviruses are widely distributed in swine, but the clinical significance of these viruses remains unclear, since they have been associated with both diarrheic and healthy pigs. In addition, there is a paucity of data on Kobuvirus prevalence in Canadian pig herds. In this study, a total of 181 diarrheic and healthy piglets were monitored and sampled on four occasions, intended to represent the different stages of production. The piglets were sampled at the nursing farms (birth to weaning stage), at the nursery farms (post-weaning stage), and at finishing farms (at the beginning and the end of the fattening stage). Fecal and environmental samples were collected during each life stage. Following viral extraction, Kobuvirus detection by RT-PCR was conducted, and positive samples were sequenced. During the late-nursing stage (6–21 days old), piglets with diarrhea shed more Kobuvirus than healthy individuals. Piglets shed more Kobuvirus during the post-weaning stage (nursery farms) than during any of the other life stages. This was evidenced in individual samples as well as in environmental samples. Over 97% of the sampled piglets shed Kobuvirus at least once in their lifetime. All piglets shedding a Kobuvirus strain or mix of strains at the nursing stage did not appear to shed another porcine kobuvirus strain at a later life stage. Overall, our findings throw light on Kobuvirus shedding dynamics and their potential role in neonatal diarrhea at the nursing stage, which appears to be the point of entry for kobuviruses into swine production systems.

Publication date

2019-08-01

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