African swine fever (ASF) is a highly contagious disease, caused by the African swine fever virus (ASFV), with nearly 100% mortality in infected pigs in Africa and Eurasia (Galindo & Alonso 2017). Following the recent outbreaks of ASF in Far East Russia and areas close to the borders of China in 2017 (Kolbasov et al. 2018), the first case of ASF outbreak in China was confirmed in the northeastern province of Liaoning in early August 2018 (Zhou et al. 2018). In mid-August 2018 outbreaks were also confirmed in Jiangsu and Zhejiang in East China and also in Henan in south-central China (Table 1). The number of confirmed cases increased from 4 in August to 19 in September, 24 in October and 26 in November, but then decreased to 21 in December 2018 and 5 in January 2019. By 25 January 2019 (when this editorial was finished), ASF were confirmed in 21 provinces (autonomous regions) and all four municipalities in China—infected over 14,000 pigs and killed over 10,000; as a result, over 169,000 pigs in infected farms were culled (Table 1). The control measures for infected farms and imposed quarantine were highly effective (Table 1), but reoccurring cases up to January 2019 in some provinces that were already on high alert (e.g. Heilongjiang and Jiangsu) suggest other problems. Although the policies of the central government are good, less strictly enforced quarantine at the local levels may be one problem. Other problems may be unknown means of transmission and reservoirs of ASFV. A report in this issue by Chen et al. (2019) adds a new twist to this emerging crisis. They showed for the first time that ASFV can infect sheep and bovines in addition to Suidae, and Dermacentor hard ticks (not just Ornithodoros soft ticks) can be vectors. They also showed the transovarian transmission of ASFV in D. niveus. The new results highlight the urgent need to study new means of ASFV transmission (esp. wildlife/domestic interface—Quembo et al. 2018) and the development of new prevention and control measures for ASF in China—the world's largest producers and market of pork.
TABLE 1.
Outbreaks of African swine fever in China since August 2018*.
