October 15, 2015

 

 Vesicular disease found in more swine herds

Posted Sept. 30, 2015

A virus associated with vesicular disease in pigs has been found in at least 12 U.S. herds in 2015.

Dr. Paul Sundberg, executive director of the pork industry’s Swine Health Information Center, said infections with the Seneca Valley virus, or Senecavirus A, has been associated with clinical signs identical to those of foot-and-mouth disease. Those signs include vesicular lesions on snouts and coronary bands, according to information from the American Association of Swine Veterinarians.

In some infected U.S. herds, mortality rates among the neonatal have been double normal rates, reaching 15 to 18 percent for one to two weeks, Dr. Sundberg said.

But Dr. Sundberg said studies so far have not confirmed that the virus causes disease, which is a subject of center-funded research.

Dr. Tom Burkgren, AASV executive director, said veterinarians need to treat any vesicular disease as a possible FMD infection and report the infection to state or federal animal health authorities.

“You have to err on the side of caution and eliminate foot-and-mouth disease as a potential diagnosis,” he said.

From Jan. 1 to Sept. 1, investigators with the Foreign Animal Disease Diagnostic Laboratory in the Department of Agriculture’s Animal and Plant Health Inspection Service received samples from 22 swine vesicular case investigations. Of 22 cases, nine were positive for SVV by virus isolation and PCR analysis, five were positive for SVV by PCR analysis only, and eight were negative for SVV, according to information provided by agency spokeswoman Joelle Hayden. In 2014, the agency conducted only five such investigations and isolated the virus in two.

The APHIS information also indicates SVV has been isolated from pigs with other clinical signs, such as those associated with central nervous system or enteric diseases, and agency officials do not know what role the virus has in any of the clinical presentations, including idiopathic vesicular syndromes. The agency also has limited data and lacks a validated serologic test, so the agency has no estimates on prevalence, incidence, or epidemiologic trends.

Dr. Sundberg said the virus has spread across the U.S., appearing in states ranging from Alabama to Hawaii. How the virus spreads and where it originated remain unknown.