I. A. Krotov
Peoples Friendship University of Russia (RUDN University); National Medical Research Center of Children Health
Russian Federation

Ivan A. Krotov - post-graduate student of the department Peoples Friendship University of Russia (RUDN University).

6 Miklukho-Maklaya str., Moscow 117198; 2/1 Lomonosov ave., 119296.

O. E. Konovalov
Peoples Friendship University of Russia (RUDN University)
Russian Federation

Oleg E. Konovalov - MD, PhD, DSc, professor, professor of department of public health, health care and hygiene Peoples Friendship University of Russia (RUDN University).

6 Miklukho-Maklaya str., Moscow 117198.

R. N. Terletskaya
National Medical Research Center of Children Health
Russian Federation

Rimma N. Terletskaya - MD, PhD, DSc, professor, project leader of organizational and analytical department National Medical Research Center of Children Health.

2/1 Lomonosov ave., 119296.

S. N. Gres
Peoples Friendship University of Russia (RUDN University)
Russian Federation

Sofiya N. Gres - assistant of the department Peoples Friendship University of Russia (RUDN University).

6 Miklukho-Maklaya str., Moscow 117198.