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The Georgia-07-like genotype II African swine fever virus (ASFV) with high virulence has been prevalent in China since 2018. Here, we report that genotype I ASFVs have now also emerged in China. Two non-haemadsorbing genotype I ASFVs, HeN/ZZ-P1/21 and SD/DY-I/21, were isolated from pig farms in Henan and Shandong province, respectively. Phylogenetic analysis of the whole genome sequences suggested that both isolates share high similarity with NH/P68 and OURT88/3, two genotype I ASFVs isolated in Portugal in the last century. Animal challenge testing revealed that SD/DY-I/21 shows low virulence and efficient transmissibility in pigs, and causes mild onset of infection and chronic disease. SD/DY-I/21 was found to cause necrotic skin lesions and joint swelling. The emergence of genotype I ASFVs will present more problems and challenges for the control and prevention of African swine fever in China.

The African swine fever virus (ASFV) was first reported in China on 3 August 2018, which subsequently triggered a severe epidemic that spreads across the country. While the ASFV has numerous underlying transmission paths in China, this study primarily assessed the possibility of ASFV transmission through the legal animal husbandry trade. The reason for this is that, historically, this transmission path is one of the critical contacts for exotic diseases to access disease-free areas. This study employed a stochastic model to assess the monthly possibility for ASFV entering respective Chinese provinces. The results of this model suggest that the risk of ASFV transmission though the legal live-pig trade is highest in the southeastern regions of China. Vulnerable regions centred around Zhejiang, Jiangsu and Anhui provinces, especially throughout the months of January and December. Liaoning province contributes most to transmission risk with 46.7% of the overall annual risk. This study quantified the risk of ASFV spread in China related to the legal trade of pigs and provides detailed and new information for the development of ASFV monitoring and control plans in China and other countries who also face the challenge of ASFV., (© 2020 Blackwell Verlag GmbH.)

African swine fever (ASF) has spread widely across China since 2018. It represents a significant threat to the pig production industry, as no treatment or vaccine is available for this disease. In this study, the geographical distribution and epidemiological features of ASF from all endemic regions of China were analyzed. We focused on the epidemiological data from 149 ASF cases among domestic pigs and wild boars, confirmed during 2018-2019. We found that, in the 1-year period from August 2018 to July 2019, ASF was reported in most geographical regions of the country, which comprises 31 provinces. The outbreaks were mainly located along the important economic zones and tended to increase southward in general. The southwest region was the most severely affected, with 22% of cases, followed by the Northeast, with 20% of cases. There was no significant difference among other regions. Additionally, the overall mean rate of case-incidence/fatality was 12.5% and 64%, respectively, in this period and varied significantly different months, with a general trend towards a decrease over time. The highest incidence rate (30.4%) occurred in April-May 2019, and the highest fatality rate (81.21%) in October-November 2018, demonstrating the marked seasonality in ASF transmission. Furthermore, anthropogenic effects were a major significant risk factor for the spread of the disease. In summary, this initial epidemiological analysis of ASF provides a global perspective on ASF and facilitates detection of trends and patterns, which will be useful for updating preventive actions at a national level and evaluating their impact on public health., (© 2019 Wiley Periodicals, Inc.)

A risk assessment was conducted to assess the risk of ASFV entry into Japan through pork products illegally brought in by air passengers from China and fed to pigs in Japan. Scenario tree modelling was used with the following entry and exposure pathway considered to be the most likely route of ASF entry: an ASFV infected pork product is illegally brought into Japan by air travellers from China; this pork product is then used in a restaurant where scrap waste is recycled for animal feed and subsequently fed to pigs without being heat-treated. Input parameter values were based on surveys conducted by the authors, scientific data gathered from the literature and official data published by government agencies. The annual probability of ASFV entry into Japan via this pathway was predicted to be 0.20 (90% prediction interval: 0.00-0.90). The wide prediction interval was mainly caused by the uncertainty regarding the dose response relation of ASFV, followed by the probability of an ASF infected pig dying on affected farms, the loading of ASFV in an infected pig and the probability of an illegally imported pork product being heat-treated in China and used in restaurants. The results of scenario analysis revealed that the annual probability of ASFV entry into Japan will increase with an increase in the number of ASF affected farms in China. The probability of ASFV entry will increase substantially even if only a small proportion of Ecofeed is not heat-treated during the production process. The probability will decrease if an increased proportion of farms that feed swill apply heat-treatment before feeding swill to their pigs. These findings indicate that stringent application of heat-treatment of Ecofeed and swill is key to protecting the Japanese pig industry from the introduction of ASFV., Competing Interests: The authors have declared that no competing interests exist.

The continuing spread of African swine fever (ASF) outside Africa in Europe, the Russian Federation, China and most recently to Mongolia and Vietnam, has heightened awareness of the threat posed by this devastating disease to the global pig industry and food security. In this review we summarise what we know about the African swine fever virus (ASFV), the disease it causes, how it spreads and the current global situation. We discuss current control methods in domestic and wild pigs and prospects for development of vaccines and other tools for control., (Copyright © 2019. Published by Elsevier B.V.)

A rapid risk assessment was conducted using a questionnaire composed of 10 questions asking experts in African swine fever (ASF) to identify and rank the potential risk factors associated with the introduction and spread of ASF in Japan. The experts participating in this risk assessment considered illegal food import, followed by transport routes and foreign workers, to be the most relevant pathway of ASF introduction into Japan. Kanto and Kyushu were identified as the most likely regions for ASF introduction. All experts agreed that China is the most likely source of ASF introduction into Japan. Most Japanese experts were of the view that the risk of ASF spread if introduced into Japan would be low, while foreign experts considered the risk to be moderate or high. Most experts answered that wild boars would play an important role in the persistence of ASF if the disease were to spread in Japan.