On November 29, 2018, European Food Safety Agency released African Swine Fever Epidemiological Analysis Report (from November 2017 to November 2018).
It is understood that the latest outbreak of African swine fever in the European Union shows that the outbreak season of African swine fever reaches its peak in winter and summer among all tested wild boars. For domestic pigs, summer is the peak of outbreak. Despite existing several observable seasonal factors, there is no evidence of causality.
Some of the original reports are as follows:
This updat on the African swine fever (ASF) outbreaks in the EU demonstrated that out of all tested wild boar found dead, the proportion of positive samples peaked in winter and summer. For domestic pigs only, a summer peak was evident. Despite the existence of several plausible factors that could result in the observed seasonality, there is no evidence to prove causality. Wild boar density was the most influential risk factor for the occurrence of ASF in wild boar. In the vast majority of introductions in domestic pig holdings, direct contact with infected domestic pigs or wild boar was excluded as the route of introduction. The implementation of emergency measures in the wild boar management zones following a focal ASF introduction was evaluated. As a sole control strategy, intensive hunting around the buffer area might not always be sufficient to eradicate ASF. However, the probability of eradication success is increased after adding quick and safe carcass removal.
Source: http://news.foodmate.net/2018/11/495968.html