Considered in the article are current trends of perfection of laboratory diagnostics of particularly dangerous infectious diseases. They are as follows: development and practical introduction of laboratory diagnostics methods based on the modern diagnostic techniques, standardization of the laboratory investigations, accreditation of the laboratories carrying out laboratory diagnostics of particularly dangerous infectious diseases, perfection of the system of external control of the laboratory investigations quality, staff training.

Заболеваемость населения ЛЗН в 2015 г. на Северо-Американском континенте была следующей. В США, по данным Центра по контролю и предотвращению заболеваний США (Centers for Disease Control and Prevention, CDC, http://www.cdc.gov/), на 17.11.2015 г. зарегистрировано 1812 случаев ЛЗН, из них 65 % с нейроинвазивной формой инфекции (в 2014 г.-1935 случаев, из них 59,4 %-нейроинвазивная ЛЗН) [5]. В Канаде в сезон 2015 г., по данным Агентства общественного здравоохранения (Public Health Agency of Canada, PHAC, http://www. publichealth.gc.ca), выявлено 78 случаев ЛЗН (в сезон 2014 г.-21) [6].

The trend towards an increase in the West Nile fever incidence among the population in the Russian Federation, recorded in the season of 2018, continued and led to a significant increase in the incidence in 2019 (the indicator was 2 times higher than the long-term average). The features of manifestations of the epidemiological process of WNF in 2019 were identified: early registration of cases of the disease, activation of natural and natural-anthropourgic foci in the Southern Federal District (90 % of the total incidence in the Russian Federation), an increase in the share of neuro-invasive forms, dominance of patients aged 50 and older in the structure of the incidence, late epidemic season ending. It was established that in the season of 2019, the lineage 2 of WNV circulated in the European part of Russia. In the Volgograd Region, simultaneous presence of the West Nile virus and Sindbis virus in mosquitoes Culex pipiens and Culex modestus was identified. It was shown that the most significant factors for predicting the epidemiological situation on West Nile fever in the Volgograd Region are the average seasonal summer air temperature and monthly average indicators of relative humidity in the spring and summer periods, and the average monthly air temperatures in the spring and summer in the Rostov Region. In the Astrakhan Region, a significant correlation dependence of the influence of the considered factors on the incidence of the population has not been established. The forecast of the development of epidemic situation in 2020 does not exclude a possible increase in the incidence in the territories of the European part of Russia, endemic for West Nile fever, and the occurrence of local outbreaks in individual constituent entities, if the complex of climatic conditions and social factors favorable for West Nile virus coincide.

Within the period of 2000-2011, in the West of Kazakhstan, identified have been five, previously unknown in the territory, natural foci of dangerous infectious diseases such as hemorrhagic fever with renal syndrome, Astrakhan spotty fever, Crimean hemorrhagic fever, West Nile fever, and tick-borne viral encephalitis. The reason is that key ecological factors for the persistence of the infections in the local biocoenoses occurred. It is characteristic that circulation of the agents of new infectious diseases is registered in the territory of the long-established natural plague and tularemia foci. Since 2000 and on, hemorrhagic fever with renal syndrome morbidity is registered in the Western-Kazakhstan Region on a regular basis. There is some evidence to identification of West Nile fever patients in the territory of Russia in 2012, which came from Kazakhstan. Based on the spatial distribution of the natural foci of various infections, Western-Kazakhstan Region has been subdivided into four areas. In order to provide for the effective prophylaxis of emerging diseases, it is essential that healthcare facilities and services dealing with infectious diseases are consolidated and reinforced, and epidemiological surveillance is improved with the current conditions in mind.

В статье на примере Саммита «Группы двадцати» в Санкт-Петербурге (5-6 сентября 2013 г.) обоснованы основные принципы обеспечения санитарно-эпидемиологического благополучия в период подготовки к мероприятию. Показана важность и необходимость оценки эпидемиологических рисков, определены приоритетные направления мероприятий в подготовительный период. Установлена приоритетность проведения эпидемиологического надзора и лабораторного контроля в отношении планируемых мест проживания участников мероприятия, поставщиков продуктов и предприятий общественного питания.Ключевые слова: массовое мероприятие, эпидемиологический надзор, эпидемиологические риски, лабораторный контроль, противоэпидемические мероприятия.Established are the basic principles of sanitary-epidemiological welfare provision in the preparations to and managing of the public event by the example of "G-20" Summit. Outlined is the significance and essentiality of epidemiological risk assessment. Specified are the areas of priority as regards anti-epidemic activities in the run-up period. Established is the priority of epidemiological surveillance and laboratory control over the places of residence of participants, caterers and supplying companies, and public catering facilities.