African Swine Fever: Spread and seasonal patterns worldwide.

Abstract

African Swine Fever (ASF) is a viral disease affecting both wild and domestic swine, with the potential for major lethality rates. In addition to direct losses for producers, its notification in a free country or zone leads to international trade restrictions. The disease has spread globally at concerning levels, with outbreaks reported in recent years across five continents. Time series analysis of ASF outbreak notifications indicates an increasing trend in Europe and Asia. For Europe, including both domestic pigs and wild boar, seasonality was pronounced in the summer and autumn (July, August, and October). Wild boar represented 78.00 % (25,017) of the reported outbreaks in the continent, with pronounced seasonality in winter (December, January and February) and a peak in summer (July). In domestic pigs, seasonality was pronounced mainly in the summer (July and August) and autumn (October). Poland and Romania were the countries with the highest number of reported outbreaks on the continent, representing 35.34 % and 22.50 % of the total in Europe, respectively. In Asia, analysis including both domestic pigs and wild boar showed pronounced seasonality in February and March. For domestic animals, a higher number of outbreaks occur in the early months of the year (mainly February, and March), in the third quarter and early fourth (August, September, October and November), with a decrease in the middle (July) and at the end of the year (December). In China, the notifications are predominantly in domestic swine, with 97.21 % (209) of the reported outbreaks in the country. For wild boars, South Korea accounts for 96.46 % (1690) of the notifications in Asia. Seasonality in Europe may be related to increased human movement during these periods and wild boar behavior. In Asia, seasonality coincides with the period immediately following the Chinese New Year, probably related to the increased national demand for pork and the movement of people and by-products in the country. Recent notifications in 2021 and 2022 in the Caribbean region have raised concerns across the Americas.