Demand-driven spreading patterns of African swine fever in China

Abstract

African Swine Fever (ASF) is a highly contagious hemorrhagic viral disease of domestic and wild pigs. ASF has led to huge economic loss and social impact worldwide. The biological mechanism of ASF's infections is still not fully understood, and the lack of preventative options at the individual level further complicates this major global health challenge. In this paper, we propose a novel method to model the spread of ASF in China by integrating the data of pork import/export, transportation networks, and port distribution centers. We first empirically analyze the overall patterns of ASF spread and performs extensive experiments to evaluate the efficacy of a number of distance measures. These empirical analyses show that the arrival of ASF is not purely based on the geographic distance from existing infected regions. The pork supply-demand patterns have clearly influenced the spread of ASF, which cannot be well explained by conventional geographical distance and the recent effective distance methods. Predictions based on the new distance measure achieve better performance in predicting the disease spreading among Chinese provinces and thus have the potential to enable more proactive and accurate deployment of interventions.

Tracing the Origin of Genotype II African Swine Fever Virus in China by Genomic Epidemiology Analysis

“…Te putative-ancestor-virus-centered radial shape of the Asian cluster suggests that samples collected from different provinces in China and other Asian countries may come from the same virus origin. According to the feld epidemiology investigation, long-distance transmission of animal or animal products played an important role in the spread of ASFV in Asia [54,55]. Not only it is true that more than half of the world's domestic pigs are raised in Asia, but also it has the highest population density of farmed pigs in the world.…”

Estimating the spatial distribution of African swine fever outbreak in China by combining four regional-level spatial models

“…China accounts for about 50% of the world’s pig production [ 11 ], and long-distance transport of pigs is inevitable given not uniformly distributed of China’s pig industry and the rapid circulation of pigs and their products. The pork demand of each province in China is uneven [ 48 ], the legal trade of live pigs is necessary and has become one of the critical spreading routes for ASF entering disease-free areas [ 18 ]. According to model prediction result, some preventive and control measures should be taken in the ASF risk area, further stopping the spread of the epidemic.…”

Development of a quadruple PCR-based gene microarray for detection of vaccine and wild-type classical swine fever virus, African swine fever virus and atypical porcine pestivirus

“…With the rapid response of our government and a series of precise control policies, the outbreak has been effectively controlled and the pig industry has been recovering in an orderly way [ 25 ]. In 2021, however, new situations for the ASF epidemic in China emerged, which showed reduced mortality, and atypical clinical signs, and some "natural variant strains" showed no hemadsorption (HAD) [ 26 ]. These natural variant ASFV strains caused subclinical symptoms, which were difficult to identify and detect at the early stage and can be easily confused with other diseases, leading to problems in differential diagnosis and prevention and control of ASFV [ 27 ].…”