Цель: Проведение анализа результатов многолетнего мониторинга вируса гриппа птиц в одной из ключевой точек Северной Евразии — оз. Убсу-Нур, Республика Тыва. Методы. Проведен анализ доступных источников и результатов собственных исследований. Для построения филогенетической дендрограммы использована программа MEGA 5.2. Топология дерева восстановлена при помощи метода присоединения соседей. Эволюционные расстояния рассчитаны с применением метода максимального правдоподобия. Достоверность оценивалась посредством бутстреп-анализа (1000 репликаций). Результаты. Проведен биогеографический анализ котловины Больших Озер и сделан обзор литературы и собственных результатов исследований циркуляции и молекулярной эпидемиологии высокопатогенного вируса гриппа H5N1 на озере Убсу-Нур. Заключение. Многолетние наблюдения на озере Убсу-Нур выявили важную роль данного биогеоценоза для сохранения и распространения вируса гриппа А в популяциях диких птиц. Плановый экологовирусологический мониторинг является основой для корректных выводов о динамике эпизоотических процессов, контроля инфекции, а также для оценки эпидемического и пандемического потенциала новых вирусных штаммов.

High pathogenicity avian influenza has a significant negative impact on poultry farming, international trade and health of wild bird populations, therefore the infection requires the utmost attention of the entire international community. The article investigates the evolutionary and epidemic processes observed in recent years in many countries of the world where avian influenza outbreaks occur; describes the ways of the infection spread; the prevalence of the virus types for the last several years, as well as the expansion of the host range, including among representatives of the Mammalia class. The change in the ratio between the virus types starting from 2020, when H5N8 subtype was responsible for the overwhelming number of the disease outbreaks reported, until 2022, when an obvious predominance of H5N1 subtype was detected is demonstrated. A noticeable expansion of the disease-affected areas in Central and South America, the influence of migration, anthropogenic and other factors on influenza spread are highlighted. The conditions facilitating the occurrence of the infection outbreaks affecting mammals, wild animals and livestock, zoo and companion animals are described. Cases of mammals’ infection on the North American and Eurasian continents in zoos, nature parks, backyards and fur farms, asa rule, coincide in time with the infection outbreaks in waterfowl populations. The WAHIS data were analyzed and the high ability of the virus to spillover from birds to mammals, such as martens (minks, otters, ferrets, badgers), cats (domestic cats, cougars, leopards, lynxes), pinnipeds (common seals, grey seals), bears (brown, grizzly, American black), bottlenose dolphins, skunks, foxes, opossums, raccoons was demonstrated. Changes in the habitats of both migratory birds and mammals, including due to some human economic activities, add an ecological and urban component to the complex task of the control and prevention of the epidemic, also posing a potential threat to humans.

The paper demonstrates data on global and national spread of subtype H9 low pathogenic avian influenza in poultry. Due to no need of the mandatory disease notification to the OIE, published data are used for the analysis of the infection spread. Cases of combined low pathogenic avian influenza clinical manifestation in poultry population are described. Challenges of the infection eradication are addressed. Global spread of А/Н9 virus in poultry, its rapid evolution and zoonotic potential require close attention. Since the disease signs and clinical course are similar to the ones of other avian infectious diseases (Newcastle disease, infectious laryngotracheitis, infectious bronchitis, metapneumovirus infection, mycoplasmosis, infectious coryza, etc.), the routine laboratory diagnosis should include tests for low pathogenic avian influenza thus facilitating the rapid response to the threat. Н9 virus circulation is reflected not only in the physical condition of birds and their productivity, but it also affects the live vaccines’ efficacy during scheduled immunizations through the reduction of their protective effect and increase of post-vaccination reactions. In spite of the availability of specific prevention, the opinions of the researchers divided between its opponents and proponents. On the one hand, the vaccination eliminates the economic loses and the virus escape into the environment, but on the other hand, it can aid to “silent” spread of the virus and its established variation that is typical in case of low strength of the poultry population immunity.

The results of the scientific expedition to Tere Khol and Uvs Nuur Lakes in the Republic of Tyva with the purpose of active monitoring of highly dangerous diseases in wild migratory waterfowl and epidemic analysis of these biotope water areas are presented in the paper. The Uvs Nuur Lake is a kind of an indicator for avian influenza introduction to the Russian Federation, because this is the resting and nesting area for many migratory wild birds during the period of mass migrations from Central and South-East Asian countries. In the process of active monitoring the complete autopsy of bird carcasses with description of organs and systems and sampling for laboratory diagnostics were performed. Droppings (pooled samples), parts of internal organs from dead and shot birds, blood (if possible) served as biological and pathological material for testing. While sampling, species were identified using an ornithological guide. The autopsy of dead waterfowl and birds shot for diagnostic purposes demonstrated a high worm burden of nematodes and cestodes. Two samples from European herring gulls were positive for avian influenza type A virus genome and subtype H13N6 was identified in one of them. Avian paramyxovirus serotype 1 (APMV-1), the agent of Newcastle disease, was found in one sample from gulls. The lakes of the Republic of Tyva are the most significant sites for sampling of biological material from wild birds, as the primary detection of highly pathogenic avian influenza virus in this territory is a serious signal of potential further virus spread and a precursor to a probable epizooty. Notwithstanding the absence of AIV very virulent isolate detections in wild bird populations the middle term prognosis for 2020 can be designated as cautious, as the avian influenza epidemic situation is deteriorating globally, especially in the European countries, and the threat of the virus introduction to the Russian territory with migratory birds still exists.

Introduction. The Lower Volga region, including the Volgograd Oblast, remains one of Russia’s most rabies-affected areas to date. Data on the genetic diversity of rabies viruses (RABVs) currently circulating in the Volgograd Oblast are insufficient, making phylogenetic analysis of RABV isolates from this region a relevant scientific objective.Objective. The study aims to conduct a phylogenetic analysis of current RABV isolates recovered from animals in the Volgograd Oblast, based on the full-length nucleoprotein gene sequence.Materials and methods. Brain tissue samples from animals diagnosed with rabies were used. The obtained nucleotide sequences of the RABV nucleoprotein gene were analyzed using the Bayesian strict molecular clock method. The spatial distribution of RABV isolates was described using Natural Earth physical map.Results. Full-length nucleoprotein gene sequencing was performed for 13 RABV isolates collected in the Volgograd Oblast. Phylogenetic analysis revealed that the RABV population in this region comprises distinct genetic variants of genetic group C, formed at different times. Genetic relationship to the isolates from Kazakhstan, Ukraine, Moldova and Central/Southern Russia indicates intensive RABV circulation in Southern European Russia. Notably, distinct virus variants were detected on the left and right banks of the Volga River.Conclusion. All studied RABV isolates collected in the Volgograd Oblast belonged to genetic group C and exhibited high genetic diversity among variants.

The paper presents the results of monitoring tests performed in the FGBI “ARRIAH” Branch in 2018 to detect AIV circulation in the Republic of Crimea. As AIVs are most frequently detected in aquatic and semiaquatic birds wild waterfowl present the greatest threat of the disease introduction and spread. That’s why the paper gives special attention to the Azov Sea and Sivash water area and describes natural biotopes of the Central and Eastern Sivash. During expeditions biological material samples were collected, bird species were identified and bird fauna was estimated in waterfowl aggregation sites. Laboratory PCR tests of the biological material collected during the expedition as well from killed birds and poultry revealed no AIV type A. As the number of wildfowl in the their usual aggregation sites decreased due to the fact that fresh water supply through the North-Crimean Canal ceased it can be assumed that the Crimean peninsula will manage to maintain HPAI freedom despite the fact that the disease is being reported close to the peninsula. Nevertheless, the threat of the virus introduction to the commercial and backyard farm stocks still exists as the peninsula is located in the bird migration routes and AI epidemical monitoring is a topical task.