Problems of VirologyProblems of VirologyВопросы вирусологии0507-40882411-2097Central Research Institute for Epidemiology1663610.36233/10.36233/0507-4088-213gtekdxEDITORIAL CONCEPTРЕДАКЦИОННАЯ КОНЦЕПЦИЯReview ArticleAvian flu: «for whom the bell tolls»?Птичий грипп: «по ком звонит колокол»?https://orcid.org/0000-0002-3192-8405ZhirnovOleg P.ЖирновОлег Петрович
Russian Federation

Academician of the Russian Academy of Sciences, Professor, Dr Sci (Biology), Head of the Laboratory

чл.-корр. РАН, доктор биол. наук, профессор, руководитель лаборатории вирусного патогенеза

zhirnov@inbox.ruhttps://orcid.org/0000-0001-8176-6582LvovDmitry K.ЛьвовДмитрий Константинович
Russian Federation

Academician of the Russian Academy of Sciences, Professor, Dr Sci (Medicine), Chief Researcher

академик РАН, доктор мед. наук, профессор, главный научный сотрудник

dk_lvov@mail.ruThe D.I. Ivaovsky Institute of Virology, The N.F. Gamaleya Research Center of Epidemiology and Microbiology, The Russian Ministry of HealthИнститут вирусологии имени Д.И. Ивановского ФГБУ «Национальный исследовательский центр эпидемиологии и микробиологии имени почетного академика Н.Ф. Гамалеи», Минздрава РоссииThe Russian-German Academy of Medical-Social and Biotechnological Sciences, Skolkovo Innovation CenterРусско-немецкая академия медико-социальных и биотехнологических наук, Инновационный центр Сколково0605202469210111821032024Copyright ©; 2024, Zhirnov O.P., Lvov D.K.Copyright ©; 2024, Жирнов О.П., Львов Д.К.2024Zhirnov O.P., Lvov D.K.Жирнов О.П., Львов Д.К.https://creativecommons.org/licenses/by/4.0https://virusjour.crie.ru/jour/article/view/16636

The family Orthomyxoviridae consists of 9 genera, including Alphainfluenza virus, which contains avian influenza viruses. In two subtypes H5 and H7 besides common low-virulent strains, a specific type of highly virulent avian virus have been described to cause more than 60% mortality among domestic birds. These variants of influenza virus are usually referred to as «avian influenza virus». The difference between high (HPAI) and low (LPAI) virulent influenza viruses is due to the structure of the arginine-containing proteolytic activation site in the hemagglutinin (HA) protein. The highly virulent avian influenza virus H5 was identified more than 100 years ago and during this time they cause outbreaks among wild and domestic birds on all continents and only a few local episodes of the disease in humans have been identified in XXI century. Currently, a sharp increase in the incidence of highly virulent virus of the H5N1 subtype (clade h2.3.4.4b) has been registered in birds on all continents, accompanied by the transmission of the virus to various species of mammals. The recorded global mortality rate among wild, domestic and agricultural birds from H5 subtype is approaching to the level of 1 billion cases. A dangerous epidemic factor is becoming more frequent outbreaks of avian influenza with high mortality among mammals, in particular seals and marine lions in North and South America, minks and fur-bearing animals in Spain and Finland, domestic and street cats in Poland. H5N1 avian influenza clade h2.3.4.4b strains isolated from mammals have genetic signatures of partial adaptation to the human body in the PB2, NP, HA, NA genes, which play a major role in regulating the aerosol transmission and the host range of the virus. The current situation poses a real threat of pre-adaptation of the virus in mammals as intermediate hosts, followed by the transition of the pre-adapted virus into the human population with catastrophic consequences.

Семейство Orthomyxoviridae состоит из 9 родов, включая Alphainfluenza viruses, куда входят вирусы гриппа птиц. У двух субтипов ‒ Н5 и Н7 ‒ помимо обычных низковирулентных штаммов описана особая разновидность высоковирулентного вируса птиц, способного вызывать заболеваемость у птиц с летальностью выше 60%. Эти и ряд других разновидностей вируса гриппа, тесно связанных с птицами, принято обозначать термином «птичий вирус гриппа». Различие высоко- (HPAI) и низковирулентных (LPAI) вирусов гриппа обусловлено структурой аргининсодержащего сайта протеолитической активации в белке НА. Вирус высоковирулентного птичьего гриппа Н5 выявлен около 100 лет назад и на протяжении этого времени вызывает эпизоотии среди диких и домашних птиц, и лишь несколько локальных эпизодов болезни зарегистрированы среди людей с начала XXI в. В последние годы зафиксирован резкий подъем заболеваемости птиц высоковирулентным вирусом Н5N1 (клайд h2.3.4.4b) на всех континентах планеты, сопровождающийся переходом вируса на разные виды млекопитающих. Регистрируемая глобальная смертность среди домашних и сельскохозяйственных птиц от данного субтипа приближается к уровню 1 млрд особей. Опасным эпидемическим фактором становятся участившиеся вспышки птичьего гриппа с высокой летальностью среди млекопитающих, в частности морских львов и тюленей в Северной и Южной Америке, норок и пушных зверей в Испании и Финляндии, домашних и уличных кошек в Польше. Изолированные от млекопитающих штаммы птичьего гриппа H5N1 клайда h2.3.4.4b имеют признаки частичной адаптации к организму человека в генах РВ2, NP, HA, NA, играющих главную роль в регуляции аэрозольной трансмиссии и круга хозяев вируса. Создавшаяся ситуация представляет реальную угрозу предадаптации вируса в организме млекопитающих как промежуточных хозяев с последующим переходом предадаптированного вируса в популяцию людей и формированием пандемии с катастрофическими последствиями.

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