One of the most tragic and heroic pages in the history of our country - the Great Patriotic War - is getting further and further away from us every passing year. The challenges faced by the medical science and healthcare system during those years demonstrated their capacity to fight for the lives and health of people, the sanitary and epidemiological well-being of the country in extremely difficult conditions in the name of victory.The employees of the Khabarovsk Research Institute of Epidemiology and Microbiology, fully fulfilled their duties both on the war fronts and in scientific laboratories, and honorably wrote their own pages in the history of the Great Victory. The memory of those events is not just a tribute to those who fought in the rear and at the front for the Motherland, but also an important aspect of preserving our historical and cultural heritage and identity of our people.

Objective of the review: to evaluate the impact of HCV and HCV polymorphisms on the formation of hepatocellular carcinoma (HCC). Main statements: Development of HCC remains one of the unresolved and complicated issues of modern healthcare system. One of the most significant risk factors of HCC development are hepatotropic viruses, including HCV. It was established that all HCV proteins (Core, E1, E2, p7, NS2, NS3, NS4A, NS4B, NS5A, NS5B) lead to dysregulation of cell proliferation and immune system function including deterioration of NK- and T-cells responses. Inhibition of pro-apoptotic protein p53 and decrease of interferon production and its antiviral activity as well dysregulation of tumor suppressor proteins network lead to development of tumor in liver tissue. HCV high mutation rate favors emergence of amino acid substitutions in viral proteins and as a result may induce pro-oncogenic processes. Such mutations were detected in E2, NS5A, but most frequently in the core gene of the virus. Conclusion: R70Q/H, L91M and K10Q/R are most common amino acid substitutions of HCV core protein that are spread within viral population and detected in the cohort of patients with diagnosis of HCC. Analysis of existing data on the topic confirmed relevance of continuing the research of HCV polymorphisms that may induce development of HCC as well as evaluation of their prevalence among people suffering from chronic hepatitis C in order to create a diagnostic test-system based on PCR technology which will allow to establish patients that have an increased risk of HCC.

The annual seasonal increase in the incidence of enterovirus infection with the registration of out-breaks in the Russian Federation and the ability of enteroviruses to recombine, leading to the emergence of new genovariants, including those with high epidemic potential, determine the relevance of constant epidemiological surveillance and molecular genetic monitoring of enteroviruses. An analysis of enterovirus infection incidence in the Far East and part of Eastern Siberia in 2024 was conducted, epidemically unfavorable territories were identified, the predominant types of enteroviruses (E30, E25, СV-A6, СV-A10, and СV-A16) were established, and a short-term forecast of enterovirus infection incidence for 2025 was presented.

Studying the epidemiological features of the COVID-19 pandemic has become a priority for epidemiologists worldwide. Currently, the assessment of the COVID-19 pandemic is based on a well-known distinction between the course of epidemics in the pre-pandemic phase, the pandemic phase, and the post-pandemic phase. Changes in the phases are associated with changes of pathogen virulence and an increase in the number of immune individuals. In the post-pandemic phase there was a quantitative decrease in the number of COVID-19 cases caused by SARS-CoV-2 omicron variant. The dynamics of morbidity and mortality from Sars-CoV-2 in the post-epidemic phase in nine regions of the Far Eastern Federal District of the Russian Federation are analyzed.

HIV-infection remains a pressing issue in both Russia and Far Eastern Federal district. Current research was conducted to evaluate HIV epidemic tendencies in the Far Eastern Federal district. Cumulative number of HIV-infected has reached 59 498 people in early January 2025. HIV screening coverage of district population has reached 35.0%. HIV-infection incidence rate equaled 31.9 per 100 000 population, prevalence rate – 411.6 per 100 000 population in 2024. Rate of men among newly infected people with HIV remained high. Heterosexual route of transmission was prevailing. A total number of 89.9% of people living with HIV were registered for regular medical check-ups and 81.6% of them received antiretroviral therapy. Preventive work was actively carried out.

The spread of drug addiction and HIV-infection is a pressing health care issue in both Russia and Khabarovsk Krai. Parenteral rout of HIV transmission associated with injecting drug use was scarce, however understanding the impact of drug addiction among population on the spread of HIV-infection is necessary to develop a strategy of awareness-raising and educational work. The conducted analysis showed stable situation concerning drug addiction. The obtained information can help target prevention efforts to reduce HIV transmission among the region's population.

Current article presents the results of evaluation of immune structure response to nine species of parasitic invasions causative agents among population of the Khabarovsk city and Khabarovsk krai in 2024. Immunoglobulin G antibodies were found among conditionally healthy people against antigens of following pathogens: Echinococcus granulosus (10.8%; 95% CI: 8.88-12.74%), Trichinella spp. (5.8%; 95% CI: 4.15-7.39%), Toxocara canis (13.8%; 95% CI: 11.74-15.9%), Anisakis spp. (11.8%; 95% CI: 9.78-13.9%), Taenia solium (2.2%; 95% CI: 1.24-3.22%), Ascaris lumbricoides (19.3%; 95% CI: 16.89-21.75%),Clonorchis sinensis (3.4%; 95% CI: 2.21-4.57%), Opisthorchis felineus (5.3%; 95% CI: 3.88-6.74), Lamblia intestinalis (9,8%; 95% CI: 7,97-11,71%). Results of the research indicate an existing contact of population with causative agents of helminthiasis confirming the necessity of optimization of the diagnostic system of epidemiological surveillance over parasitic diseases.

The analytic material presents data on epidemiological situation on biohelminthiasis and geohelminthiasis incidence in the Khamchatsky krai as well as the results of sanitary and parasitological surveillance of environment during 2019-2023. A pronounced declining trend of ascaridiasis incidence was oserved. Results of sanitary-parasitic expertise of fishery products, environment, veterinary and sanitary expertise of wild meat showed a continuing biohelminthiasis and geohelminthiasis hazard in the Kamchatsky krai.

The article presents the results of long-term observations of 97 patients who had suffered various clinical forms of tick-borne encephalitis (TBE), with a long period of IgM antibody formation. The latter may indicate the persistence of the virus in the human body. Possible causes of this condition are discussed, including secondary (virus-mediated) immunodeficiency. The importance of life history and disease history in the process of differential diagnosis of residual effects of tick-borne encephalitis and progression of symptoms (chronization of the process) is also considered.The issue of the importance of life history and disease history in the process of differential diagnosis of residual effects of tick-borne encephalitis and progression of symptoms (chronization of the process) is also considered.