Low Pathogenetic Strain of ASF Detected in China Causing New Concern

A new low virulent strain of African Swine Fever identified in China that may be less likely to be detected is raising concern. A low virulent Genotype 1 strain of African Swine Fever similar to a strain that caused infection in Portugal many years ago has been identified by a laboratory in China.

Swine Health Information Center Executive Director Dr. Paul Sundberg says this new Genotype 1 virus is less virulent than the Georgia 07 Genotype 2 virus that is causing the epidemic around the world and may be more difficult to detect.

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

Genotype 1 is a relatively low virulent genotype of ASF. It still causes infection but it doesn't cause the devastating disease that Genotype 2 does. Genotype 1 can make a pig sick but generally they can recover. The implication for that is that Genotype 1 may be able therefore to spread among a population, a region, between farms with more ease and lower detectability than Genotype 2 that is more highly pathogenic.

If you have a virus that will cause severe disease in pigs and have 100 percent mortality in a group of pigs or in a region, it's rather easy to say I've got something. There's something different going on here and we better find out what it is.

If you have a virus that causes a disease that looks very much like other things that are normal or endemic in the area and pigs recover and go on in production it's easier to dismiss that and say it must have been this or it must have been that rather than checking for ASF so it may be harder to detect because of the lower virulence and that's really the concern.