García *1, G.; Jordà 1, R.; Alvarez 1, G.; Bernal 1, I.; Nodar 1, L.
1HIPRA, Amer (Girona), Spain
*Corresponding author: gonzalo.garcia@hipra.com
Background & Objectives
Oedema disease (OD) is an enterotoxaemia caused by Escherichia coli, which possesses adhesion factors enabling the bacteria to colonise the small intestine and produce the verotoxin 2e (VT2e). VT2e is absorbed into the blood circulation and causes vascular damage, growth problems, nervous disorders and mortality1. The aim of this study was to evaluate the presence of the gene coding for the verotoxin on farms where OD was suspected in a selection of countries worldwide.
Materials & Methods
For the analytical procedure, 19,633 oral fluid samples were obtained from 3,785 farms from 47 countries, over the last 6 years (from 2017 to September 2023).
These oral fluids were then transferred to FTA Elute cards and samples were sent to HIPRA DIAGNOS for performance of a qPCR analysis targeting the gene coding for the verotoxin (Vt2e)2. A farm was considered positive when at least one of the samples was positive.
Results
The mean prevalence of positive farms globally was reported to be 62.75% positive (2375 out of 3785 farms). When assessing the prevalence by region, we observed that the prevalence is high and very constant worldwide. In Europe, we analysed 2,224 farms,
with 61.1% testing positive. In America, 64.1 % of 679 farms were positive. In Asia, 65.9% out of a total of 882 farms were positive.
Analysing the prevalence over the 6 years of the study, this remained stable over time: in 2017 it was 68.5% positive out of 54 farms analysed; in 2018: 56.5% out of 481 farms; in 2019: 63.6% out of 546; in 2020: 62.4% out of 583; in 2021 62.4% out of 726; in 2022:
64.7% out of 816 and finally during 2023: 64.6% out of 579 farms were positive.
Discussion & Conclusion
The results obtained are in line with findings from a previously published systematic literature review, where the Vt2e gene prevalence was estimated to be between 30 and 70%3. It demonstrates that OD remains a major challenge for swine production worldwi-
de, particularly in the context of sustainable production with limited use of antibiotics.
References
1. Fairbrother J. et al. 2019, Disease of Swine, Eleventh Edition 807-811.
2. Valls, L et al. 2018. Improving edema disease diagnosis in pigs by detec-
ting the vt2e toxin gen in oral fluid by qPCR. ESPHM proceedings.
3. Barba,E et al.2020Global mass screening on sub-optimal farms reveals
a high risk of Oedema Disease. IPVS proceedings
