Clinical and epidemiological characteristics of influenza in 2015-2016 and 2016-2017
Objective. To analyze the clinical and epidemiological characteristics of influenza during the 2015-2016 and 2016-2017 epidemic seasons. Materials and methods. Federal State Statistical Observation Forms № 1, 2, 5, and 6; information from the official website of the Research Institute of Influenza, Ministry of Health of Russia; and the materials of the Russian Federal Service for Supervision of Consumer Protection and Human Welfare were used. Results. In the last season, influenza vaccination coverage in the Russian Federation increased from 31 to 38%. Immunization coverage increased in all risk groups and decreased by 18% among pregnant women in 2016 compared to 2015. Influenza vaccination of children in the 7-17 age group increased by 18.8% in 2016 compared to 2015. The compared epidemic seasons varied in timing and duration. The 2015-2016 season lasted 5 weeks while the rise in the incidence of influenza in 2016-2017 started earlier and its duration was 11 weeks. In the 2016-2017 epidemic season, the influenza mortality rates were 94.5% lower than those in 2015-2016. Conclusion. The found differences are clearly determined by the level of immunization coverage in all areas of the country, by the characteristics of the properties of the circulating pathogen, and by improvements in the clinical and laboratory diagnosis of infection.