6.5 Correlation between the epidemiological cycles of ASF
The ASF outbreaks in several countries in Europe in the year 2014-2017, seems to follow the common domestic epidemiological cycle, i.e. the infection circulates among small pig farms, affecting few commercial farms, and frequently spills over to wild boars (EFSA, 2014).From these data, a previously undescribed epidemiologic cycle of ASF became evident: a cycle that focuses on the wild boar population and its habitat as a virus reservoir and led to the addition of a new cycle known as ‘wild boar-habitat cycle’ (Chenais et al., 2018; FAO, 2020b). This cycle is characterized by (i) direct transmission between infected pigs/wild-boar and susceptible wild boar; and (ii) indirect transmission through ASF contaminated carcasses in the habitat and the possible subsequent intraspecies scavenging, and thus, the cycle continues (Probst et al., 2017).
Possibility of future outbreaks or establishment of endemism of ASF in India will depend upon the maintenance of epidemiological cycles of ASF as well as distribution of reservoirs and susceptible hosts. We have analysed the four established epidemiological cycles of ASF from Indian perspective to describe the risk associated with each cycle (Figure 2).