As there is currently no vaccine for African Swine Fever, the only way to fight the virus is to have extremely good biosecurity practices in place on farm and across borders. Knowledge is power in this respect: ASFv is an ‘enveloped virus’. What does this mean in practice and how does it help to be as well prepared as possible?
由于目前还没有针对非洲猪瘟的疫苗，对抗这种病毒的唯一方法是在农场和边境上采取非常好的生物安全措施。在这方面，知识就是力量：非洲猪瘟病毒是一种“包膜病毒”。这在实践中意味着什么？如何尽可能做好准备？
As is well known, African Swine Fever (ASF) is a highly contagious viral haemorrhagic disease that can be fatal to pigs and wild boars. Currently, for this virus, no approved vaccine exists.
众所周知，非洲猪瘟（ASF）是一种高传染性病毒性出血热，可致猪死亡。目前，对于这种病毒，还没有获批的疫苗。
According to different sources, the routes of transmission of the infectious agent are as follows:
根据不同来源，传染媒介的传播途径如下：
·Oro-nasal route by contact with an infected animal carrying the virus and by exchange of secretions. The virus is present in all body fluids and tissues of the infected animal;
·经口鼻途径与携带病毒的受感染动物接触和交换分泌物。病毒存在于受感染动物的所有体液和组织中；
·Oro-nasal route by direct contact with the virus present in the environment where it can survive (excrement, fodder, liquid manure, manure, litter, equipment, vehicles, clothing, etc.);
·经口鼻途径直接接触病毒所存在的环境（粪便、饲料、水肥、粪肥、垃圾、设备、车辆、衣物等）；
·Through the air, in the barn, over very short distances in the case of high density pigs;
·高密度养殖群中，空气传播；
·Ingestion of water or contaminated food (contaminated food waste, contaminated fresh meat that has not been sufficiently heat treated, etc.);
·摄入受污染的水或食物（受污染食物废料、未经充分热处理的受污染鲜肉）；
·Bites from ticks of the genus Ornithodoros carrying the virus and biting flies as well.
·被携带病毒的鸟齿龙属的扁虱或苍蝇叮咬。
Good biosecurity is essential to protect pigs from ASF. Photo: Koos Groenewold
良好的生物安全在预防猪瘟上至关重要。图：Koos Groenewold
Sensitive to disinfectants
对消毒剂敏感
African Swine Fever virus is a double stranded DNA virus single member of genus Asfivirus and the family Asfarviridae. Several genotypes (22) of the species have, however, been identified and virulence differs greatly from one isolate to another.
非洲猪瘟病毒是一种双链DNA病毒，是非洲猪瘟病毒属和非洲猪瘟病毒科的一个成员。目前已识别该物种的22个基因型，但毒力在不同的分离株之间有很大的差异。
The extracellular enveloped viruses have a diameter that varies between 175 to 215 nm. They are relatively large compared to other viruses, some of which only measure 10 to 30 nm (see Figure 1). Their capsid is an icosahedral structure of capsomeres surrounded by an outer layer mainly made up of lipids, qualifying them as large enveloped viruses. This outer envelope is essential for infection.
细胞外包膜病毒的直径在175到215纳米之间。与其他病毒相比，它们相对较大，其中一些病毒只有10 - 30nm长(见图1)。它们的衣壳是由主要由脂质组成的外层包围的衣囊二十面体结构，因此被认为是大包膜病毒。这个外膜是造成感染的必要条件。
In the fight against ASF, it is an advantage that these viruses belong to groups of large enveloped viruses, as they are much more sensitive to disinfectants than viruses without an envelope (known as ‘naked’), especially if they are small.
在与非瘟的斗争中，有一个优势是这些病毒属于大包膜病毒，比没有包膜的病毒（即“裸病毒”）对消毒剂更敏感，特别在其很小的时候。
That is why the virucidal activity of disinfectants is tested on a reference virus: Cytopathic Bovine Orphan (ECBO) virus. It is a small naked virus (27 nm in diameter), easy to grow in the laboratory and very resistant to biocides. Therefore, the disinfectants’ virucidal activity which has been demonstrated on this reference virus, according to European standardised methods, is capable of demonstrating virucidal activity on ASFv, whatever the genotype.
这就是为什么消毒剂的抗病毒活性是在一个参考病毒上测试的：牛呼肠孤病毒（ECBO）。这是一种小型的裸病毒（直径27纳米），易于在实验室中生长，对杀菌剂有很强的抵抗力。因此，消毒剂的抗病毒活性已经在这一参考病毒上得到了证明，根据欧洲标准方法，能够证明其对非瘟病毒的抗病毒活性，无论哪种基因型。
Dissemination of the virus
病毒传播
The virus is relatively resistant in the environment and can therefore spread very quickly. Some strains can remain infectious across a wide range of pH values from 4 to 13. Studies also show virulent activity of strains stored for five and seven years at 5°C, for 18 months at 20°C and between ten and 30 days at 37°C. The virus can also survive in protective media such as soil or animal faeces for five to six months and up to 30 months in chilled meat. However, it is inactivated at a temperature of 60°C applied for 30 minutes.
非瘟病毒在环境中抵抗力相对更强，因此可以迅速传播。有些菌株在pH值4-13的范围内仍然具有传染性。研究还表明，在5°C条件下保存5年和7年、在20°C条件下保存18个月、在37°C条件下保存10天到30天的菌株具有剧毒活性。病毒还可以在土壤或动物粪便等保护性介质中存活5至6个月，在冷冻肉中存活30个月。然而，在60°C的温度下，30分钟便失活。
In general, it is observed that resistance and survival of enveloped viruses is much higher based on temperatures below 10°C compared to high temperatures (above 20°C), in the environment or under disinfectant treatment (see Table 1).
总体而言，我们观察到，与高温（20℃以上）环境或消毒剂处理下相比，在10℃以下，包膜病毒的抗性和存活率要高得多。
General biosecurity measures
常规生物安全措施
The fight against the disease lies in prevention: avoiding the spread of the virus from infected or endemic areas (strict imports, monitored transportation of animals, etc.).
与非瘟的斗争重点在于预防：避免病毒从受感染或流行地区传播进来（严格控制进口、监测动物运输等）。
On farms, it is essential to ensure the protection of the animals with regards to all external sources and entrants:
在农场，必须切实保护生猪，免受所有外来物料的威胁：
·Access to buildings should be controlled: use of personal protective equipment is pivotal to access livestock buildings;
·进入猪舍应受到控制：使用个人防护设备是进入牲畜栏舍的关键；
·Footbaths should be placed at the entrances of each building;
·每栋建筑物的入口处应设置洗脚盆；
·Vehicles should be cleaned and disinfected inside and out and on-site (including inner parts of the mudguard);
·车辆里外（包括挡泥板内侧）应进行清洁消毒；
·Tractors and trailers used should be cleaned and disinfected to remove manure;
·使用的拖头及拖架须清洁及消毒，以清除粪便；
·All clothing should be washed at 60°C;
·所有衣物应在60°C下洗涤；
·Improvement of building maintenance, pest control, rodent control, liquid manure removal, etc.;
·改善猪舍维修、防治虫鼠、灭鼠、清除粪肥等；
·Improvement of cleaning and disinfection procedures on all surfaces of buildings and equipment and the environment in general;
·改进栏舍和设备所有表面的清洁和消毒程序，以及整体环境；
·Monitoring of entrants (food, water, etc.);
·监控进入猪场的物料（水源、饲料等）；
·Monitoring of animal health (abnormal signs or symptoms).
·监测生猪健康状况（及时发现异常体征或症状）。
Biocidal strategy
生物消毒剂
Animal health company Huvepharma is marketing the biocidal glutaraldehyde/ammonium products Vulkan Max and Vulkan Air. Both have been tested on ECBO virus according to EN standards. Vulkan Max, in particular, demonstrated efficacy on specific ASFv:
动保公司Huvepharma正在出售生物杀灭戊二醛/铵产品Vulkan Max和Vulkan Air。根据欧洲标准，这两种病毒都经过了ECBO病毒测试。尤其是Vulkan Max，其对特异性非瘟病毒的疗效得到了证明：
·At less than 0.8%, according to the last EN 14675 standard; 30 minutes at 10°C;
·根据最新的EN14675标准，10℃下作用30分钟，低于0.8%，；
·At 0.2% according to the Russian standard; 1 hour at 20°C at low soiling level conditions;
·按俄罗斯标准，20°C低污条件下作用1小时，0.2%；
·At 0.5% according to the Russian standard; 1 hour at 20°C at high soiling level conditions.
·按俄罗斯标准，20°C高污染条件下作用1小时，0.5%。
If the disease is reported
若疾病确诊
If a case is proven, establishment of a management procedure for hazardous areas includes:
一旦病情得到证实，危险区域管理程序的建立包括：
·Elimination of animals: slaughter of all animals in the farms concerned;
·扑杀生猪：屠杀相关猪场所有生猪；
·Isolation and securing of the site: rigorous and controlled confinement and isolation procedures;
·猪场隔离保护：严格和受控的限制和隔离程序；
·Cleaning and disinfection of premises in collaboration with the competent authorities and selected service providers.
·与有关当局和选定的服务商合作，对猪场进行清洁和消毒。
As observed in Europe and in some regions of Asia, the transmission of ASF seems to depend largely on the wild boar population density and their interaction with low-biosecurity pig production systems. Good knowledge and management of the wild boar population and a good coordination among the veterinary services, wildlife and forestry authorities are required to successfully prevent and control ASF.
正如在欧洲和亚洲一些地区所观察到的，非洲猪瘟的传播似乎在很大程度上取决于野猪种群密度及其与低生物安全性生猪生产系统的相互作用。要成功地预防和控制非洲猪瘟，需要对野猪种群有良好的认识和管理，并在兽医服务、野生动物和林业部门之间建立良好协调。
原文链接
https://www.pigprogress.net/Health/Articles/2019/10/Preparing-for-ASFv-An-enveloped-virus-479463E/
文章来源：Pig Progress
（文/爱猪网记者刘坤颖编译，爱猪网原创，转载请注明出处）
