The influenza epidemic in Russia during the 2014–2015 season

The goal of this study was to compare the data on the intensity of the influenza A(H3N2) and B epidemic (especially the death toll) in the 2014–2015 season with the previous epidemic of the 2013-2014 season. The data on weekly morbidity, hospitalization, deaths from influenza, and acute respiratory diseases in different age groups of inhabitants of 59 cities located in 7 Federal districts of the Russian Federation were collected using the database of the Research Institute of Influenza.Analysis of this data showed that the influenza epidemic in 2014-2015 began earlier (in December) compared to the epidemic of 2013-2014, and spread mainly from Europe through Russia to the East. The intensity of the epidemic of 2014-2015 was higher compared to the previous one. The epidemic was more prevalent by regions and cities and a wider engagement of different age groups (except children up to 2 years of age) was observed. At the peak of the epidemic, the morbidity level was higher, the average duration of the epidemic was longer, and the number of patients among cities’ inhabitants (especially among children 7-14 years of age and adults) was higher than in the previous season. The rates of hospitalization with influenza and acute respiratory viral infections (ARVI) among patients older than 65 years were also higher (1.4 times) as well as the frequency of hospitalization with a diagnosis of “influenza” (2.7 times) and the number of deaths from laboratory confirmed influenza (1.8 times).Although the influenza pandemic virus strain A(H1N1)pdm09 was not the main causative agent of the 2015 epidemic and was distributed sporadically it still remained the leading cause of deaths from influenza in the course of this epidemic (45.5% of all cases). The deaths associated with this strain were recorded only in the European part of Russian Federation.The goal of this study was to compare the data on the intensity of the influenza A(H3N2) and B epidemic (especially the death toll) in the 2014–2015 season with the previous epidemic of the 2013-2014 season. The data on weekly morbidity, hospitalization, deaths from influenza, and acute respiratory diseases in different age groups of inhabitants of 59 cities located in 7 Federal districts of the Russian Federation were collected using the database of the Research Institute of Influenza. Analysis of this data showed that the influenza epidemic in 2014-2015 began earlier (in December) compared to the epidemic of 2013-2014, and spread mainly from Europe through Russia to the East. The intensity of the epidemic of 2014-2015 was higher compared to the previous one. The epidemic was more prevalent by regions and cities and a wider engagement of different age groups (except children up to 2 years of age) was observed. At the peak of the epidemic, the morbidity level was higher, the average duration of the epidemic was longer, and the number of patients among cities’ inhabitants (especially among children 7-14 years of age and adults) was higher than in the previous season. The rates of hospitalization with influenza and acute respiratory viral infections (ARVI) among patients older than 65 years were also higher (1.4 times) as well as the frequency of hospitalization with a diagnosis of “influenza” (2.7 times) and the number of deaths from laboratory confirmed influenza (1.8 times). Although the influenza pandemic virus strain A(H1N1)pdm09 was not the main causative agent of the 2015 epidemic and was distributed sporadically it still remained the leading cause of deaths from influenza in the course of this epidemic (45.5% of all cases). The deaths associated with this strain were recorded only in the European part of Russian Federation

Эпидемия гриппа в России в сезон 2014–2015 гг.

The goal of this study was to compare the data on the intensity of the influenza A(H3N2) and B epidemic (especially the death toll) in 2014–2015 season with the previous epidemic of 2013-2014. The data on weekly morbidity, hospitalization, deaths from influenza and acute respiratory diseases in different age groups of inhabitants of 59 cities located in 7 Federal districts of the Russian Federation were collected using the database of the Research Institute of Influenza. Analysis of this data showed, that the influenza epidemic in 2014-2015 began earlier (in December), compared with the epidemic of 2013-2014, and spread mainly from Europe through Russia to the East. The intensity of the epidemic 2014-2015 was higher, compared to the previous one. The epidemic was more prevalent by regions and cities and wider engagement of different age groups (except children up to 2 years) was observed. At the peak of the epidemic the morbidity level was higher, the average duration of the epidemic was longer and the number of patients among cities inhabitants (especially among children 7-14 years of age and adults) was higher than in the previous season. The rates of hospitalization with influenza and ARI among patients older than 65 years were also higher (1.4 times) as well as frequency of hospitalization with a diagnosis of “influenza” (2.7 times) and the number of deaths from laboratory confirmed influenza (1.8 times). Although the pandemic influenza virus A(H1N1)pdm09, was not the main causative agent of the epidemic 2015, it still was the main cause of deaths from influenza (45.5% of all cases). In spite of influenza A(H1N1)pdm09 virus sporadic prevalence, deaths from it were reported only on the European part of territory of Russia.Целью работы было сравнение показателей интенсивности эпидемии гриппа, вызванной штаммами вирусов гриппа А(H3N2) и В, в сезон 2014–2015 гг. с предшествующей эпидемией 2013–2014 гг. Особое внимание уделено летальным исходам от гриппа. Использована база данных НИИ гриппа по еженедельной заболеваемости, госпитализации, летальным исходам от гриппа и ОРЗ в различных возрастных группах населения 59-ти наблюдаемых городов, расположенных в семи Федеральных округах Российской Федерации. По сравнению с эпидемией 2014 г. эпидемия гриппа в 2014–2015 гг. началась раньше (в декабре) и распространялась, в основном, с запада на восток – из Европы по территории России в восточном направлении. Показатели интенсивности эпидемии 2015 г., в сравнении с предыдущей, были выше в отношении распространенности по округам, городам и вовлеченности возрастных групп населения (кроме детей до 2-х лет). Показатели заболеваемости на пике эпидемии, средней продолжительности эпидемии, уровней заболеваемости населения в городах (особенно среди детей 7–14 лет и взрослого населения) были выше, чем в предыдущем сезоне. Участились и случаи госпитализации с гриппом и OPВИ среди лиц старше 65 лет (в 1.4 раза), среди госпитализированных повысилась доля больных с диагнозом «грипп» (в 2.7 раза) и число летальных исходов от лабораторно подтвержденного гриппа (в 1.8 раза). Штамм пандемического вируса гриппа, A(H1N1)pdm09, хотя и не был основным возбудителем эпидемии 2015 г., попрежнему стал основной причиной летальных исходов от гриппа (в 45.5% всех случаев); причем случаи смерти, ассоциированные с этим штаммом, регистрировали только на европейской территории России при спорадическом уровне его распространения