Source: Du Caicai and Cai Xuejiao, Caixin, 21 June 2021, photo credit: Space and Culture
New, difficult-to-detect variants of the African swine fever virus circulating in China have spread the disease to pig herds across the country this year, leading to rising incidents of mass infection on farms and stepped-up control measures to stop swine fever’s further spread into livestock supply chains.
Since late last year, provinces including Henan, Shandong, Hebei, Jiangsu and Guangdong, as well as the Guangxi Zhuang autonomous region, have reported new outbreaks. Farms have reported that infected pigs typically show only mild symptoms in the early stages but have a longer incubation period, making it difficult to diagnose the disease before mass infection spreads across farms.
In late February, researchers from the Harbin Veterinary Institute said in a report published in the academic journal Science China Life Sciences that they had documented a milder but harder-to-detect mutation of the virus.