0
High mortality (~30-50%) cases of Streptococcus equi ssp zooepidemicusis have been reported on western Canada assembly yards and on four commercial sow farms (causing abortions) in 2019. It was also seen recently in two cases of U.S. sow and feeder assembly yards.
Clinical signs observed included lethargy, weakness, high fever (in case from hog buying station), swift spread among pigs of highly varied sources within the affected premises, and rapidly escalating mortality.
The Iowa State Diagnostic Laboratory (ISU VDL) found both the Canada and U.S. strains to be strikingly similar to the ATCC strain isolated from swine outbreak(s) of high mortality in China in the mid-1970s that reportedly involved the loss of more than 300,000 pigs.
Streptococcus equi ssp zooepidemicusis is not commonly isolated from swine, with the ISU VDL only reporting 6 isolations from clinical diagnostic case investigations of swine over the past 10 years. Thus, there is minimal information concerning the novelty of this particular variant of S. zooepidemicus.
Awareness should reinforce biosecurity efforts, particularly related to transport and collection points. Further study is needed to better understand the relevance and prevalence of S. zooepidemicus in North American swine.
October 30, 2019/ 333 editorial using information from SHIC and ISU-VDL
