Crimean Hemorrhagic Fever in the World. Epidemiological and Epizootiological Situation in the Russian Federation in 2024, Morbidity Rate Forecast for 2025

The review discusses the situation on Crimean hemorrhagic fever (CHF) in the world and analyzes the epidemiological and epizootiological situation in the Russian Federation in 2024. 42 CHF cases were detected in Russia in 2024, which is 1.6 times higher than in 2023 and 1.8 times lower than the average annual values (2015–2024 average – 79.1 cases per year). The mortality rate was 4.7 %, which is 15 % higher than the long-term annual average (4.1 %). The epidemically significant index of abundance of the main vector of the Crimean-Congo hemorrhagic fever virus (CCHF virus), Hyalomma marginatum ticks, was 5.6 times higher than the threshold value at the points of long-term observation in April; the index of abundance on cattle reached 16. 8 (threshold value – 3). Cases of CHF were registered for the first time in Gergebil and Tsumadinsky Districts of the Republic of Dagestan. In Russia, in 2024, CCHF virus markers were detected in 0.64 % of samples; CCHF virus belonging to the genetic lineages Europe-1 (V) (82.3 %) and Europe-3 (VIII) (17.6 %), characteristic for the territory of the Russian Federation, circulated in endemic areas. Continuous registration of CHF cases, the prevalence of severe and moderately severe disease courses, the on-going expansion of epidemically active territory within the natural focus of CHF indicate the persistence of an unfavorable epidemiological situation regarding CHF in the south of the European part of the Russian Federation in 2025 with unsatisfactory implementation of preventive measures.