At present no effective measures for specific prevention and treatment of African swine fever have been developed. The control strategy for the disease is designed for rapid diagnosis of infected animals with subsequent slaughter and decontamination (stamping out). The present review deals with current epidemic situation for African swine fever and examines features of the virus genomics and genetic differentiation of the isolates. The Russian Federation has been ASF-infected since 2007. Since that time the disease has been one of the key problems in pig farming of this country inflicting great economic losses, both directly and indirectly. The disease continues to spread. In January 2014 African swine fever was introduced to Lithuania, then pervaded Poland, Latvia, Estonia, Romania, Belgium and Moldova. Since 2018 the disease outbreaks have been reported in Asia (China, Vietnam, and Mongolia). Specific structure of the virus and long genome, encoding genes with unknown function, and circulation of 24 genotypes and 9 serotypes of the virus hinder the development of ASF vaccine. The article shows that the use of many specific genetic markers during determination of relationship and study of pathways of ASF virus global spread is the most accurate method.

Functions of many African swine fever virus genes and multigene family members have not been yet understood. In particular, no virus genes directly associated with pig virulence have been identifed. Identifcation of such genes will enable preparation of deletion mutant ASF virus strains as well as development and testing of pilot safe vaccines based on the said virus strains. Comparative analysis of the virus biological characteristics and detection of differences in its genome structure affecting certain phenotypic features is a main method used for the virus basic pathogenicity and immunogenicity examination. The most interesting and effective approach to addressing this problem is an analysis of changes in the gene structure during ASF virus adaptation to replication in continuous cell culture. The said factors have made continuous cell culture-adapted variant ASF virus preparation necessary. Variant viruses with modifed biological features were prepared during adaptation of ASFV Odintsovo 02/14 isolate to replication in CV-1 cell culture. Lethality level was 16.7% when pigs were infected with adapted variant virus at 30th passage and survived animals became resistant to reinfection with homologous virulent ASFV Arm07 isolate. It should be noted that the virus passage in non-permissive cell culture up to 30 serial passages did not result in changes in its genotype; however, a large 3,000 bp deletion similar to that one in continuous Vero-cell culture-adapted BA71V strain genome appeared in right terminal variable region of the genome.

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РЕЗЮМЕВ настоящее время актуальным вопросом в профилактике и лечении вирус-ных инфекций является изучение действия на организм человека и животных индукторов синтеза интерферона -веществ природного или синтетического происхождения, стимулирующих продукцию собственного интерферона. Од-ним из синтетических индукторов интерферона является полудан. Он пред-назначен для стимуляции клеточного иммунитета, который способен предотвращать заражение и развитие заболевания, а также обладает противови-русным и иммуномодулирующим действием. В клетках и тканях организма по-лудан в основном стимулирует выработку α-интерферона и в меньшей степени -β-и γ-интерферона, образование которых препятствует размножению вируса в клетке. Представлены результаты влияния полудана на репродукцию ряда вирусов свиней в первичных и перевиваемых культурах клеток путем индукции синтеза интерферона и других цитокинов, понижающих уровень инфицирования клеток. В результате проведенных исследований выявили взаимосвязь внесения индуктора интерферона и изменения уровня репродукции вирусов репродуктив-но-респираторного синдрома свиней, трансмиссивного гастроэнтерита свиней и африканской чумы свиней. Также установлен высокий уровень интерфероно-генной активности полудана в первичных культурах клеток тестикул и селезенки свиней по сравнению с перевиваемыми линиями клеток почки эмбриона свиньи (СПЭВ) и почки макаки-резуса (MARC-145). Интерфероногенная способность по-лудана была умеренной для клеток MARC-145 и не установлена для клеток СПЭВ.Ключевые слова: репродуктивно-респираторный синдром свиней, трансмиссивный гастроэнтерит свиней, африканская чума свиней, полудан, интерферон.