Routes of Senecavirus A transmission identified in breeding herds
A study of the way swine breeding herds were likely infected with Senecavirus A (SVA) underscores the importance of encouraging adherence to biosecurity procedures.
Researchers from Iowa State University conducted an epidemiological investigation of six US swine breeding herds infected with SVA, which has been associated with vesicular signs that can resemble foot-and-mouth disease.
Their study included large and small herds with varying degrees of biosecurity in both swine-dense and swine-sparse areas.
The investigators used a standard form to collect relevant data and had detailed discussions with herd veterinarians and farm personnel about SVA’s clinical presentation and risk events that occurred in the 4 weeks prior to the first observation of clinical signs. Next, they subjectively assigned each event with a risk level of low, medium or high for SVA introduction.
While they identified multiple potential routes of infection, the researchers concluded the highest risks for introducing SVA were by indirect transmission by contaminated people — particularly on-farm employee entry — by livestock trailers or by carcass-removal equipment, K.L. Baker and colleagues reported in the February 2017 issue of Transboundary and Emerging Diseases.
They recommend the veterinary industry improve communication with producers about the importance of biosecurity measures and provide encouragement to improve compliance to protect herds from SVA and other diseases.
One of the farms in their study, for example, had biosecurity procedures better than typical for US breeding herds, but compliance wasn’t 100%. Five of the six farms didn’t have any written biosecurity protocols or formal biosecurity training for employees, they said.
 Baker KL, et al. Systematic Epidemiological Investigations of Cases of Senecavirus A in US Swine Breeding Herds. Transbound Emerg Dis. 2017 Feb;64(1):11-18.