[1] Hosp Nacl Ninos Dr Carlos Saenz Herrera, Serv Infectol, Pediat Infectol, San Jose, Costa Rica
[2] Serv Infectol Pediat Clin Colsanitas Bogota, Dept Enfermedades Infecciosas, Pediat Infectol, Bogota, Colombia
[3] Ctr Med Univ Cent Este, Pediat Infectol, Santo Domingo, Dominican Rep
[4] Univ Peruana Cayetano Heredia, Inst Nacl Salud Nino INSN, Oficina Epidemiol, Pediat,Fac Med,Pediat Infect, Lima, Peru
[5] Hosp Cayetano Heredia, Serv Pediat, Lima, Peru
[6] Univ Cent Caribe, Pediat, Epidemiol, San Juan, PR USA
[7] Consejo Adm Hosp Pediat, Buenos Aires, Argentina
[8] Amer Hlth Fdn, Publ Hlth WDC, Washington, DC USA
[9] Univ Metropolitana Santos, Pediat & Postgrad Med Sch, Sao Paulo, Brazil
[10] Hosp Univ Pediat Agustin Zubillaga, Serv Infectol, Barquisimeto, Venezuela
[11] Med UCLA, Barquisimeto, Venezuela
[12] Inst Nacl Pediat Mexico, Mexico City, DF, Mexico
[13] Minist Hlth, Tech Unit Surveillance Resp Transmiss & Immunopre, Sao Paulo, Brazil
[14] Univ Republ UdelaR, Fac Med, Dept Pediat, Clin Pediat, Montevideo, Uruguay
[15] Udelar, Fac Med, Escuela Grad, Diplomatura Profundizac Infectol Pediat, Montevideo, Uruguay
[16] Inst Nacl Pediat, Mexico City, DF, Mexico