Strep Zoo Outbreaks Caused by Different Strains

The Swine Health Information Center reports outbreaks of Strep zoo, which caused high mortality in the United States, were caused by different strains of the bacteria. Streptococcus zooepidemicus, a bacterial infection which results in the sudden death of pigs, was identified in Canada in March 2019 and has since been found in several U.S. states, including outbreaks in 2019 in Ohio and Tennessee and in January, 2021 in Indiana.

The outbreaks prompted the Swine Health Information Center to fund a project conducted at Iowa State University and the National Veterinary Services Laboratory to provide more information.

SHIC Executive Director Dr. Paul Sundberg says the infection in Indian wasn't as severe as the one in Tennessee and Ohio and although both were identified as Strep zoo, they had different sequences.

Clip-Dr. Paul Sundberg-Swine Health Information Center:

You might say it was close cousin but it wasn't the same bacteria. This bacteria is common in a number of different animals and we wanted to make sure that we understood whether or not a particular bacteria was starting to circulate in our swine herd.

If a particular strain or a particular sequence was circulating in the swine herds, that gives us a different picture of a potential emerging issue. What probably happened was isolated transmission from some other species to pigs for these isolated outbreaks.

They're not necessarily related even though they are Strep zooepidemicus. It looks like it's a different bacteria and that's what we're watch for because we want to make sure we understand the transmission, we understand the risk to the national swine herd should there be one from Strep zoo.