[1] FBUN Res Inst Epidemiol & Microbiol, St Petersburg, Russia
[2] City Clin Hosp 40, St Petersburg, Russia
[3] City Clin Hosp 31, St Petersburg, Russia
[4] City Childrens Hosp 17, St Petersburg, Russia
[5] St George Great Martyr Hosp, St Petersburg, Russia
[6] City Childrens Hosp 1, St Petersburg, Russia
[7] City Mariinsky Hosp, St Petersburg, Russia
[8] Inst Emergency Care, St Petersburg, Russia
[9] FBUN Central Res Inst Epidemiol, Moscow, Russia
[10] Eastern Central Hosp, Tallinn, Estonia
[11] Univ Tartu, Tartu, Estonia
[12] Vilnius City Clinic Hosp, Vilnius, Lithuania
[13] Univ Clin Hosp, Riga, Latvia