As directed by the Federal service for surveillance on consumers rights protection and human wellbeing (Rospotrebnadzor) during two years professionals of the FBIS Khabarovsk research institute of epidemiology and microbiology of the Rospotrebnadzor carried out routine analysis of epidemiologic situation concerning COVID-19 in Republic Sakha (Yakutia), Kamchatka, Khabarovsk, Primorsky krai, Amur, Magadan and Sakhalin oblast, Jewish autonomous oblast and Chukotka autonomous okrug. Current article presents data according to comparative analysis of COVID-19 incidence in nine abovementioned regions of the Far Eastern Federal district conducted during weeks 31-43 of years 2020 and 2021. Growth rates and rise in intensive indices of incidence and mortality were shown as well as dynamic of diseased to convalescent COVID-19 patients’ ratio. An attempt of uncovering a relation between an increase of COVID-19 incidence and number of imported COVID19 cases as well as share of repeated cases of COVID-19 was performed.

Analysis of ARI and influenza etiology during COVID-19 pandemic was conducted. Substantial role of new coronavirus as an interfering factor with other ARI pathogens was showed. SARS-CoV-2 circulation among three cohorts of examined people (examination conducted among 124 039 people) during year 2020 was revealed. Viral RNA was detected in 18.5% of total cases, in 9.4% of exposed people and in 3.1% of people that underwent preventive screening. Assessment of circulation frequency among ARI pathogens was performed in years 2019, 2020 and during January – March of year 2021. SARS-CoV-2 predominated among other respiratory viruses and its prevalence during the last two years of observation equaled 34.4% and 33.6%. Senior citizens were mostly afflicted by new coronavirus.

A complex analysis of background objects contamination was performed during SARS-CoV-2 pandemic. SARS-CoV-2 presence was detected on household goods in a home site of infection, surface washouts in public areas, on food. Crude wastewater proved to be extremely contaminated – viral RNA was detected in 16.5±3.1% of samples, hospital surface washouts were also highly contaminated with SARS-CoV-2 RNA (6.6±3.1%).

Epidemiological and molecular-genetic analysis of enteroviral meningitis was conducted in constituent entities of the Far Eastern and Siberian Federal districts during the period from year 2017 up to year 2019. Unfavorable epidemic situation concerning enteroviral meningitis incidence was revealed during the examined period of time in the Khasnodar kray, Khabarovsk krai, Sakhalin oblast and Tyva Republic. Molecular-genetic methods of research identified prevalence of Enterovirus B in patients diagnosed with enteroviral meningitis. Annual changes of enterovirus types (excluding ЕСНО30, ЕСНО-9 и Coxsackie В-5) that caused diseases of central nervous system were revealed. Apart of that some novel virus types that can cause elevation of enteroviral meningitis incidence were detected in examined territories.

Epidemiological and molecular-genetic analysis of norovirus infection was performed during the period of years 2015-2020 in a number of constituent entities of the Far Eastern Federal district (Khabarovsk krai, Jewish autonomous region and Amur oblast). Incidence of acute intestinal infections during years 2015-2019 maintained at high levels with an increasing tendency of acute intestinal infections number of specified etiology. In the structure of the diseases, norovirus was prevalent. In the year 2020 significant decline of acute intestinal infections incidence compared to previous years of observation was registered in analyzed constituent entities of the Far Eastern Federal district. Molecular-genetic analysis revealed nine different norovirus genotypes in the observed territories of the Far Eastern Federal district that are spread globally and cause infection outbreaks in different regions of the world: GII.17, GII.2, GII.3, GII.4, GII.7, GII.12, GII.6, GIX.1 and GII.14.

The HIV epidemic both in Russia and in the Far Eastern Federal District continues to be an urgent medical and social phenomenon. The number of HIV-infected in the Far Eastern Federal District as of 01.01.2021 reached 49 046 people, while a decrease in the growth rate of the prevalence rate was noted, which is 414.4 per 100 thousand population. The epidemic is in a concentrated phase. The coverage of HIV testing in the district's population was 25.8%. In most cases, HIV infection occurs through heterosexual sex. 79.1% are registered at the dispensaries, and 59.9% of all people living with HIV receive ARVT. This publication presents the results of an epidemiological analysis carried out in order to identify the features of the development of the epidemic process in 2016-2020 among 11 territories that are part of the Far Eastern Federal District.

Molecular-genetic analysis of 48 serum samples collected from people diagnosed with HIV-infection residing in the Sakhalin oblast (n=14) and Republic Sakha (Yakutia) (n=34) was performed. Among observed patients HIV-variant IDU-A continues to be dominant and was found in 72.9±6.4% of samples. HIV-recombinant forms were found in 12 cases: CRF02_AG – 1 (2.1±2.1%), CRF63_02A1 – 11 (22.9±6.1%). Primary drug resistance mutations were detected in 25 patients that underwent antiretroviral therapy (ART) (25/45, 55.6±7,4%) which means that these patients need alternative regimen of ART. In the structure of drug resistant mutations most dominant were those that determine immunological and virological inefficiency of NRTI and NNRTI. Viral strains with multiple drug resistance against two classes of antiretroviral drugs were identified in 55.6±7.4% of samples.

Territorial centers for prevention and combat against AIDS of the Far Eastern Federal district (FEFD) conduct substantial outreach and awareness-raising campaigns in order to lower spread of HIVinfection among population of the region that resulted in decline of HIV-prevalence growth rate and increased public awareness levels on issues of HIV/AIDS. Preventive work in the FEFD include public events (special events, lectures, counselling) as well as issuing printed matter, posts on social media, Internet, TV programs and conducting behavioral studies.

Evaluation of herd immunity of healthy population of Khabarovsk city against relevant strains of influenza viruses during period preceding the epidemic season was performed. The lowest protection with specific immunoglobulins was revealed against virus strain A/Cambodia /е826360/2020/H3N2/. Mentioned viral strain circulation was revealed during 3^rd – 4^th quarters of the year 2021. Antigen structure of new A/H3N2/ variant differs from known strains of A/H3N2/. This fact allows us to assume that the new strain can overcome specific herd immunity that population acquired during previous diseases.

Current article presents results of epidemiological diagnosis and epidemiological assessment of events that took place in years 2017-2018 and in year 2021. First of them was a long-lasting outbreak of respiratory diseases and pneumonia in the Birobidzhan psychoneurological asylum with number of affected patients equaled 166 people (150 patients and 16 staff members). Fatal outcomes were registered. Main pathogens were as follows – Influenza virus B, S. pneumoniae, H. influenzae. Other bacteriological pathogens were also identified and all of them did not have sings of multiple drug resistance (MDR). Evaluation of autopsy material (lung tissue of patient that died from pneumonia) showed presence of K. pneumoniae with MDR and ESBL-production formation of which was associated with hospital environment.Second situation was associated with development purulent-septic infection among newborns (12 children) in an obstetric hospital of the Khabarovsk city. Phenotypical and molecular-biological typing showed differences between the strains isolated from children (K. pneumoniae ESBL +, RAPD-type А) and staff members (strains sensitive to drugs of different RAPD-types – B, C, D but hypermucoviscous,). Two independent strains of K. pneumoniae among newborns and staff members that caused outbreak in and obstetric hospital were detected. Third situation – formation of pneumonia outbreaks associated with SARS-CoV-2 during years 20202021. During the period of new coronavirus pandemic in year 2021 a total number of 106 samples of autopsy material obtained from patients with pneumonia were examined. Prevalence of carbapenem-resistant K. pneumoniae (43.4%) that replaced ESBL-variants was observed.Efficiency of task-oriented utilization of bacteriological and molecular-biological methods and techniques in order to provide scientifically grounded evaluation of different epidemiological situations was showed.

Current article presents the results of evaluation of ixodic tick suction territorial distribution in population of different administrative territories of the Khabarovsk city during epidemic season of years 2019-2021. Most of the inquiries concerning tick suction was observed in Zheleznodorozhniy, Krasnoflotskiy and Industrialniy city districts. Tick-borne borreliosis infection rate equaled 18.3% (95% CI: 15,1-21,5%). Tick-borne encephalitis virus antigen was detected in 23 ticks (2.4%; 95% ДИ: 1.423.38%). Performed analysis indicates a necessity of annual epidemiologic surveillance over infections spread by ixodic ticks in the territory of Khabarovsk city.

Epidemiologic analysis on helminthiases and protozoiases in the Khabarovsk krai was performed during years 2016-2020. Results of seroepidemioliogical and parasitological evaluation of region population are discussed. A discrepancy between registered and reported prevalence of helminthiasis causative agents among region population is presumed. The results of current research confirm a necessity of optimizing diagnostic subsystem of epidemiological surveillance over parasitic diseases.

Literature review covers the issue of COVID-19 disease progression in people living with HIV and oncology patients. These two groups of patients are at risk of infectious diseases of different etiology due to immune response impairment. Analysis of scientific data provided evidence of a higher risk of severe course of the disease and higher chance of fatal outcome due to COVID-19 in HIV-positive people and hemato-oncological patients as well as those with lung cancer. However, there are some peculiarities. For example, people living with HIV that undergo antiretroviral treatment and oncological patients with solid tumors without metastasis have not been reported to have heavier course of COVID-19 compared to control groups. On the other hand, comorbidities (tuberculosis, cardiovascular diseases, diabetes, kidney diseases) increase the risk of unfavorable outcome.