FEATURES OF THE INFECTIOUS PROCESS OF AFRICAN SWINE FEVER

Abstract

The article presents a comprehensive analysis of the pathogenesis features of African swine fever (ASF) – a highly dangerous viral contagious disease affecting wild and domestic pigs of all breeds and ages. The main stages of pathogenesis are considered: portals of entry of infection, primary and secondary viremia, viral tropism for monocytes and macrophages, as well as mechanisms of immunopathological reactions. The relevance of the study is due to the ongoing threat of ASF spread, which causes colossal economic damage to pig farming, as well as the insufficient knowledge of pathogenetic mechanisms, which hinders the development of effective specific prevention tools. It is shown that the ASF virus enters the organism primarily through the oronasal route, after which primary replication occurs in the tonsils and regional lymph nodes. Viremia then develops, ensuring dissemination of the pathogen to target organs, which include the spleen, lymph nodes, liver, lungs and bone marrow. It has been established that the main target cells of the virus are monocytes and macrophages, in the cytoplasm of which viral genome replication occurs. Infection of these cells leads to the activation of pro-inflammatory cytokines, including interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), which induces the development of a "cytokine storm", which in turn causes massive apoptosis of T- and B-lymphocytes in lymphoid organs. It is noted that the ASF virus encodes specific genes involved in the regulation of apoptosis, which contributes to the survival of infected macrophages and long-term virus persistence in the host organism. It is shown that the nature of pathological changes depends on the form of the disease. In acute and peracute courses, lymphocyte apoptosis and necrosis of infected cells dominate, whereas in the chronic form, an autoimmune component with immune complex deposition is suggested. The results of the analysis indicate the extreme complexity of ASF pathogenesis and the need for further research to understand the mechanisms of viral persistence, immunosuppression and the development of prototype safe and effective vaccines.