May 24, 2021

Less deadly variant of ASF discovered in Chinese provinces


A research team from the Chinese Academy of Agricultural Sciences has found natural mutation in African swine fever (ASF) genotype II virus appearing in some provinces in China.


However, the epidemic strain of ASF showed low lethality.


The team had carried out systematic surveillance of ASF in some provinces and regions of China from June to December 2020, isolating 22 genotype II ASF epidemic strains.


A study, that was conducted by an ASF lab from the Harbin Veterinary Research Institute in Northeast China's Heilongjiang Province, found that there are at least four natural variants of ASF genotype II with low lethality.


The clinical manifestations of the variant are relatively concealed, and it is likely to have been prevalent among pigs in the fields, causing persistent infections, chronic course of diseases and deaths, according to the findings.


"The concealed manifestations of the variant will increase difficulty of early diagnosis of ASF and bring challenges to the prevention and control of the disease in China, so great attention must be paid to it and countermeasures should be formulated and adopted soon," said Zhao Dongming, a research fellow at the institute.


The study was published in Science China Life Sciences, a Chinese academic journal for life sciences.


At least 24 genotypes of ASF have been identified worldwide, and the most prevalent one in Asia is genotype II.


There are currently no commercial vaccines or effective treatment for ASF.


- Global Times