West Nile Fever in the Russian Federation in 2022, the Incidence Forecast for 2023

• Published in: Problems of Particularly Dangerous Infections
• Main Authors: E. V. Putintseva, S. K. Udovichenko, D. N. Nikitin, N. V. Boroday, A. A. Baturin, A. Yu. Machneva, A. S. Antonov, N. A. Zarubin, A. V. Toporkov
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: Federal Government Health Institution, Russian Research Anti-Plague Institute “Microbe” 2023
• Subjects: west nile fever; west nile virus; epidemiological situation; monitoring over the causative agent; prognosis; Infectious and parasitic diseases; RC109-216; khanty; khanty-mansi; Mansi
• Online Access: https://doi.org/10.21055/0370-1069-2023-1-75-84; https://doaj.org/article/8bab163a24884548b44a361ac5f99dde

The review presents an analysis of West Nile fever (WNF) epidemiological situation in the Russian Federation in 2022 and the summarized results of monitoring over the pathogen. The following features of the WNF epidemic process in Russia are outlined: the decrease (by 4 times) in the incidence rates compared to the long-term average values against an extremely extensive nature of manifestations (16 constituent entities in 6 federal districts), including the detection of local cases in 5 new territories (Tver, Tambov, Vladimir Regions, Khanty-Mansi Autonomous District, and Karachay-Cherkess Republic), predominant registration of incidence in the Central Federal District (51 %), early start and termination of the epidemic season. There is a decrease in the proportion of neuroinvasive forms in the structure of incidence, prevalence of females and the age group of “60 years and over”, as well as record rate values of people infected at the place of residence in cities, which is associated with the peculiarities of case detection, namely, screening examinations of febrile patients in hospitals by efforts of the Reference Center, according to the results of which 60 % of all registered patients with WNF in Russia were diagnosed. Monitoring studies of the Reference Center in the territory of the Central, Southern and North-Caucasian Federal Districts confirmed the intensive circulation of the pathogen. The low level of officially registered incidence is caused by insufficiently effective identification of patients. Molecular genetic studies have shown that West Nile virus lineage 2 circulated in the European part of Russia, both in epizootic and epidemic cycles. Phylogenetic analysis has revealed that 4 West Nile virus isolates found in Astrakhan, Volgograd Regions, the Republic of Kalmykia and Stavropol Territory in 2022 belong to a new genovariant of the genotype 2, first identified in Russia in 2021. Possible complication of the epidemiological situation in all federal districts of the center and south of the ...