Clinical and epidemiology characteristics of Influenza in seasons 2016/17 and 2017/18

Abstract

Оп the analysis of 257 maps of children with influenza A and B at the age of 2 months — 1 7 years, two groups were distinguished: 1 group — 90 people of the 201 6/1 7 season; 2 group — 167 people of the 2017/18 season.

In the 201 6/1 7 season influenza A dominated (93.3%, n = 84) compared with influenza B (6.7%, n = 6) (p < 0,05). 2017/18 was characterized by the detection of influenza A in 68.9% (n = 115) of patients and B in 31.1% (n = 52) (p < 0,05). Along with the late onset of an epidemic rise in the incidence of influenza in 2 group, the 2017/18 season was characterized by the simultaneous circulation of influenza A and B, while in 1 group there was a sequential change of influenza A to B. Patients with influenza up to 2 years prevailed in 1 group (25.6%) compared with 2 group — 1 2.6% (p < 0,05). In the 2017/18 season more often patients were hospitalized 2—5 years old (40.1%, n = 67 vs 33.3%, n = 30) and 6—1 0 years old (29.9%, n = 50 vs 1 5.5%, n = 14) (p < 0,05). In 2 group the majority of those hospitalized were 2—3 and 6—7 years old (23.9% and 1 8.6% respectively). In both seasons the influenza had typical clinical symptoms, but in 2 group 7.7% had hemorrhagic and myalgic syndromes, which was not observed in 1 group. In the blood of patients of 2 group leukopenia prevailed at all ages: up to 1 year 55.5%, 1—5 years old — 43%, 6—10 years old — 52.5%, older than 1 2 years old — 1 0% compared with patients of 1 group (p < 0,05). Lymphocytosis in normocytosis was detected in children over 1 2 years old (82%). In 2 group compared with 1 group thrombocytopenia was more frequently detected at all ages: 50.3% (n = 84) versus 14.4% (n = 13) (p < 0,05).