[1] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Boston, MA USA
[2] Natl Ctr Dis Control, Tbilisi, Georgia
[3] CDC, Div Healthcare Qual Promot, Atlanta, GA 30333 USA
[4] Tbilisi State Univ, Tbilisi, Georgia
[5] Natl Ctr Surg, Tbilisi, Georgia
[6] Mechnikov State Med Acad, St Petersburg, Russia
[7] Harvard Univ, Childrens Hosp, Sch Med, Boston, MA USA