Article presents materials on formation and development of sanitary-epidemiological service in the Russian Far East and in the Khabarovsk krai in particular. A link between opening new Amur region territory and organization of sanitary service is showed. Significance of public health during the years of civil war is presented. Importance of Khabarovsk infirmary that was organized on the base of existing sanitary-biological institute which is currently named as FBUN Khabarovsk research institute of epidemiology and microbiology of the Federal service for surveillance on consumers rights protection and human wellbeing (Rospotrebnadzor) is demonstrated. Three outstanding employees that stand at the origins of the institute organization are discussed.

By the decree of Council of People’s Commissars, dated September 15, 1922 foundation for development of specialized sanitary-epidemiological institutions was set. Establishment of sanitary-epidemiological service in the Khabarovsk krai as well as in the country took place during lean years after civil war has ended. Development of the service was carried out by training new sanitary physicians, widening their tasks and notable increase of sanitary-epidemiological institutions network. Current article presents main stages of the Khabarovsk krai service history and most important achievements of sanitary-epidemiological work during a lapse of a hundred years. Should be noted that sanitary-epidemiological service of the Khabarovsk krai had a challenging path of constant evolvement and improvement. During all stages of development, sanitary-epidemiological service presented scientific methodological organized nature, multitasking and coordinated integrity as well as ability to correctly and timely respond for the needs of society and government in realization of effective public health protection.

Tick-borne encephalitis stays a pressing issue for scientists and clinical practitioners infectious disease specialists, neurologists and epidemiologists. Article presents materials on history of tick-borne encephalitis discovery in the Russian Far East as well as results of many years of comprehensive research conducted by Far Eastern scientists on the study of this severe natural focal infection. Virus isolation and studies of the new disease in the Russian Far East played an important role in development of Russian virology. Expeditions in the Russian Far East during 1937-1940 years allowed to collect data that served as basis of academician E.N. Pavlovsky theory about natural-focality of vector-borne diseases. Modern economic interest in the Russian Far East, potential growth of migration indices make the issue of combat against tick-borne encephalitis and other natural-focal diseases important among non-immune population.

Current review illustrates recent science-to-practice achievements of the FBUN “Khabarovsk research institute of epidemiology and microbiology” of the Rospotrebnadzor. Implementation of seven scientific themes each of which can be applied to practice was discussed. Evaluation of pneumonia epidemiology associated with hospital acquired infections was most important topic during COVID-19 pandemic. Research based on molecular-genetic technologies applicable to epidemiology, prevention and diagnosis of HIV-infection, viral hepatitis, enterovirus infection, acute intestinal infections were important as well. Results of long-term research in the field of parasitic and natural focal diseases were demonstrated. Main goal of the institute work is methodological and practical support of sanitary epidemiological wellbeing concerning challenging infectious and parasitic diseases among population of the Far Eastern Federal district.

Fifth wave of COVID-19 pandemic was registered in the Far Eastern Federal district (FEFD) of the Russian Federation during winter and spring periods of year 2022. Highest incidence (931.3 0/0000) was registered during sixth calendar week of the year (from 7th to 13th February). Territorial divergence of COVID-19 incidence with highest rate in the Republic Sakha (Yakutia) was detected. Unstable situation was registered in Sakhalin, Amur and Jewish Autonomous oblasts. Decline in weekly mortality rate (from 1.8 to 1.34%) due to new coronavirus infection was revealed in the FEFD. Inverse correlation between mortality and Omicron genovariant percentage was discovered. It was revealed that Omicron has replaced Delta variant by week 10 (from 7th to 13th March) of the 2022 calendar year. Should be noted that during the period of observation proportions of Omicron genetic lines changed: BA.1 was characterized by weekly growth and subsequent decline, as for BA.2 – weekly growth of circulation activity among population was revealed. Significant positive correlation between percentage of BA.1 and BA.2 lines and percentage of vaccinated people among people infected with COVID-19 was detected. Common features of incidence growth and decrease of mortality in different constituent entities of the FEFD during fifth wave of COVID-19 were caused by importation of COVID-19 cases and following spread of new Omicron genetic variant. The new genovariant is more contagious compared to Delta variant and can cause breakthrough infections after vaccination or previous infection more often. Omicron infection generally causes less severe disease than infection with prior variants.

Epidemiologic and molecular-genetic surveillance of enterovirus infection (EVI) in 2021 in constituent entities of the Far Eastern federal district (FEFD) and Siberian federal district (SFD) allowed to reveal peculiarities of epidemic process development, identify constituent entities that have unfavorable situation concerning the disease. Conducted epidemiologic investigation of EVI outbreak revealed existence of single source of infection. Short-term prognosis of incidence for year 2022 showed significant tendency for growth of new infections in four territories of the FEFD (Primorsky and Zabaikalsky krai, Amur and Sakhalin oblast). Relatively favorable EVI incidence rates are expected in SFD constituent entities.

Analysis of infection rate with SARS-CoV-2 in different observation groups during years 2021 and 2022 (1st quarter of the year) was performed. A total number of 85188 people were observed. Infection rate among apparently healthy people equaled 2.4%, among people having ARI of unknown etiology – 14.0%, among close contacts – 10.8%. Dynamics of the virus infection rate during the observed year was revealed. Complex diagnosis of respiratory infections was preformed. This allowed to confirm previously observed trend – interference between SARS-CoV-2 virus and other respiratory viruses. SARS-CoV-2 predominance over other causative agents was detected among patients with pneumonia. Carriage of respiratory viruses without disease manifestation was discovered.

Highest indices of community-acquired pneumonia (CAP) incidence were registered during January, February and December of year 2021 in the Khabarovsk krai. Adult population of the Khabarovsk krai totaled 98.7% of CAP cases and incidence levels among adults was almost 20 times greater than among children. During first quarter of the year 2022 rise in number of CAP among adult population as well as increase of incidence among children were registered in the Khabarovsk krai. Etiological structure of CAP among the Khabarovsk krai population was mostly presented by viral pathogens in 39.5% of the cases, bacterial flora and intracellular pathogens caused CAP in 38.0% of cases, viral-bacterial mixt infections were presented by 22.5% of cases.

Article presents results of bacteriological evaluation of nasopharyngeal smears (110 samples) and sputum (68 samples) that were obtained from different patients suffering from pneumonia that were hospitalized in a certain medical institution during the same period. Comparative characteristics of causative agents types, their percentage in biological material of patients as well as drug resistance were performed. It is shown that percentage of main groups of bacterial pathogens isolated form nasopharyngeal smears and sputum did not differ significantly. Main causative agent found in both sputum and smears was Klebsiella pneumoniae. Sputum samples had more narrow spectrum of causative agents and lower percent of drug-resistant variants compared with similar data found in nasopharyngeal smears which could be the result of treatment. The results of comparative analysis provide evidence on nasopharyngeal smears usage as clinical samples for etiological diagnosis of pneumonia and drug-resistance analysis for further treatment regimen selection.

HIV-infection remains a pressing issue in both Russia and Far Eastern Federal district. Cumulative number of HIV-infected has reached 51 804 people in early January 2022. HIV screening coverage of district population has reached 28.5%. HIV-infection incidence rate equaled 31.1 per 100 000 of population and prevalence rate – 637.1 per 100 000 population in 2021. A high rate of men among newly infected people with HIV remained high. Heterosexual route of transmission was prevailing. A total number of 78.48% of people living with HIV were registered for regular medical check-ups and 79.9% of them received antiretroviral therapy. Current research presents results of epidemiological analysis of HIV epidemic in the Far Eastern Federal district and is aimed at determination of preventive work priorities.

Paper presents results of sociologic research that evaluated levels of students awareness on HIV-infection in the Khabarovsk krai in order to determine prognosis of epidemic development and management of preventive work. The study revealed adequate awareness on HIV-infection transmission routes. However, not all students have information about possible preventive measures in order to avoid being infected with HIV and can underrate the danger of individual risk of contracting HIV. Myths and phobias concerning HIV-positive people persist among young generation. Alongside with awareness programs on HIV-infection and formation of responsible behavior habit it is important to make HIV-testing accessible and free for young people.

HIV-infection epidemic remains a pressing issue for both Russian and Khabarovsk krai healthcare systems. Substance addiction plays a substantial role in spread of HIV. Parenteral route of HIV-infection spread due to drug injections in the Khabarovsk krai is declining during recent years. Surveillance over substance addiction incidence and its influence on the course of HIV-epidemic is needed in order to develop strategy of HIV-prevention work.

Current literature review addresses a pressing healthcare issue revealing ratio of COVID-19 active clinical forms to asymptomatic carriers based on data presented by Russian and foreign authors. It was shown that in the beginning of COVID-19 pandemic number of patients with manifestation of COVID-19 symptoms was higher than number of asymptomatic cases. However commencing from end of year 2020 number of COVID-19 asymptomatic “carriers” started to raise especially after spread of COVID-19 “Omicron” variant. This fact can increase the burden on the healthcare system due to spread of the virus by asymptomatic carriers that during one incubation period can become ill.

Lambliasis is a world-wide spread disease and is a common cause of diarrhea in children and adults. Causative agent of the disease is transmitted by fecal-oral route when water and food products that were contaminated by cysts were consumed. Main method of lambliasis laboratory diagnosis is detection of cysts or trophozoites of the parasite in stool samples. Several additional methods of lambliasis detection are also utilized polymerase chain reaction and enzyme-linked immunosorbent assay. Current article presents review of laboratory diagnosis methods of lambliasis and issues that are associated with their application.

Current short report presents results of molecular-epidemiological investigation of norovirus infection outbreak that occurred in January 2022 in kindergarten of the Vostochniy village located in the Khabarovsk krai. Norovirus GII.4 [P16] was identified as causative agent. Contamination of food products with the virus was most likely the cause of the outbreak.

Current article presents a case of West Nile fever diagnosed in an employee of National Guard of the Russian Federation. A fourfold increase of IgG specific antibodies against the virus in paired serum was detected as well as negative test-results of ELIZA for tick-borne encephalitis. This allowed to make a diagnosis of West Nile fever, mild flu-like form. This case of West Nile fever promotes interest because it had domestic route of transmission in the Far Eastern Federal district.