What can we learn from the five-year African swine fever epidemic in Asia?

Abstract

Today’s global swine industry is exposed to the unprecedented threat of African swine fever (ASF). Asia, the site of the most recent epidemics, could serve as a huge viral reservoir for the rest of the world given the severity of the damage, the huge swine industry, and the high volume of trade with other countries around the world. As the majority of ASF notifications in Asia today originate from pig farms, the movement of live pigs and associated pork products are considered critical control points for disease management. Particularly, small-scale or backyard farms with low biosecurity levels are considered major risk factors. Meanwhile, wild boars account for most notified cases in some countries and regions, which makes the epidemiological scenario different from that in other Asian countries. As such, the current epidemic situation and higher risk factors differ widely between these countries. A variety of studies on ASF control have been conducted and many valuable insights have been obtained in Asia; nevertheless, the overall picture of the epidemic is still unclear. The purpose of this review is to provide an accurate picture of the epidemic situation across Asia, focusing on each subregion to comprehensively explain the disease outbreak. The knowledge gained from the ASF epidemics experienced in Asia over the past 5 years would be useful for disease control in areas that are already infected, such as Europe, as well as for non-affected areas to address preventive measures. To this end, the review includes two aspects: a descriptive analytical review based on publicly available databases showing overall epidemic trends, and an individualized review at the subregional level based on the available literature.

Strategies for Transboundary Swine Disease Management in Asian Islands: Foot and Mouth Disease, Classical Swine Fever, and African Swine Fever in Taiwan, Japan, and the Philippines

“…Another important differentiating factor lies in the presence or absence of TADs. Given the threat of the ASF pandemic in Asia since its first appearance in 2018 [ 6 ], it is essential to comprehend the prevalence and management of FMD and CSF to evaluate the resilience and vulnerability of swine industries in each island ( Figure 1 ). Disparities in disease control measures ( Table 1 ) and response strategies give rise to distinct challenges and opportunities within their pig farming sectors.…”

“…The swine industry faced an unprecedented threat with the onset of the 2018 ASF outbreak in China and neighboring countries. These outbreaks led to considerable economic losses, affecting more than 18 Asian countries [ 6 ]. Additionally, ASF outbreaks were reported in both wild boars and domestic pigs.…”

— Invited Review — Current status, challenges and prospects for pig production in Asia

“…Over the last two decades, major infectious diseases such as FMD and PRRS have caused a direct impact on pig production in Asia countries, especially on farms with low biosecurity (small-scale pig farms) [11,[44][45][46]. In Asia, following the emergence of ASF virus in China in 2018, ASF has been reported in several other Asian countries, including Vietnam, Cambodia, North Korea, Laos, North Korea, Myanmar, Indonesia, Republic of Korea, India, and Thailand [47]. The spread of ASF has reduced pig populations and pork production, causing substantial economic losses to pig production in Asian countries [11,14,48].…”

Disease Course of Korean African Swine Fever Virus in Domestic Pigs Exposed Intraorally, Intranasally, Intramuscularly, and by Direct Contact with Infected Pigs

“…The first epidemic began in 1957 and was terminated in 1999 in Europe, except for in Sardinia, Italy [ 1 ]. When ASFV suddenly emerged at a pig farm in Georgia in 2007 [ 2 ], the second epidemic started and unprecedented pandemics have continued [ 3 ]. ASF rapidly transmitted from Georgia to the other Caucasus countries and Russia and has expanded westward and eastward [ 4 ].…”