THE IMPACT OF SEASONAL FACTORS ON THE DYNAMICS OF INCIDENCE RATE OF INFECTIOUS MONONUCLEOSIS IN DIFFERENT AGE GROUPS (ON THE EXAMPLE OF NIZHNY NOVGOROD)

Abstract

Infectious mononucleosis (IM) is a widespread disease. Currently, there are no clear data on the seasonality of IM, and factors affecting on the dynamics of the disease are not determined. The aim of the study was to investigate the seasonal factors affecting on the dynamics of IM incidence rate among children and adult population of the city of Nizhny Novgorod. A retrospective analysis of the incidence rate of IM among contingents of the different age in the city of Nizhny Novgorod in 2010-2015 was executed. The highest incidence rate was shown to be observed in children aged up to 6 years. The seasonal dynamics of the incidence rate of IM in different age groups was analyzed. The seasonal component derived from the decomposition of the time series of incidence rate was used for the analysis. The presence of the spring and autumn periods of seasonal rise and summer period of seasonal fall of the incidence rate, was shown regardless of the age of the group. The change of power of the impact of seasonal factors on the incidence rate of IM was found in 2010-2015. Over 6 years the contribution of seasonal factors in the incidence rate decreased in children under 13 years and, on the contrary, increased in adolescents over 13 years and adults. The dependence of the seasonal dynamics of the incidence rate of IM on climatic factors: temperature, humidity, precipitation and insolationwas studied. In children under 6 years and adults a negative correlation of the seasonal component values and the air temperature and precipitation values was found. In children aged of 7-13 years there was established a negative correlation between seasonal incidence rate of IM values and the air temperature and insolation values, as well as the positive correlation of the humidity values. In adolescents aged of 14-17 years a negative correlation of seasonal component values and the air temperature and insolation values was found.