On behalf of the Swine Health Information Center, the Iowa State University Veterinary Diagnostic Lab is conducting a genetic analysis of recent Streptococcus zooepidemicus cases identified in US Assembly Yards.

Speaking to Farmscape, Swine Health Information Center Executive Director Dr Paul Sundberg says this organism is a sporadic cause of disease in multiple animal species and, while it's rarely associated with disease in swine, it's been reported in Manitoba, Wisconsin, Ohio, Tennessee and North Carolina.

"In the genetic analysis that's been done so far - and that's still ongoing- it looks like this strep that's causing the specific problem in pigs, although it's a commensal in horses, probably originated in China," explains Dr Sundberg.

"It looks like that was the first report of this particular Streptococcus showing up in China and that was 20 years ago.

"Now, this year, for unknown reasons, we see it in North America and we see what's happening.

"We do know from the epidemiology work with looking at the bacteria and its effect in pigs and how it's moved in those assembly yards that it can be a very quick progression of disease with very high mortality rates and that is certainly of concern.

"But I also want to stress that this is a normal Streptococcus out in the environment that got into the wrong species and it's causing problems in there so we want to make sure that we learn those lessons and do the best we can do to make sure we know how to clean and disinfect and prevent infections in the future."

Dr Sundberg stresses this doesn't appear to be an epidemic or to be widespread but rather it appears to be related infections moving from one place to another.