children(4) varicella(3) Preschool children(3) pediatric(3) outbreak(3) Chickenpox(3) Varicella vaccine(3) Complication(3) vaccine effectiveness(3) peripheral facial palsy(3) Breakthrough varicella(3) Treatment(2) Chronic Hepatitis B(2) leptospirosis(2) Diagnosis(1) Hepatitis A vaccine(1) socioeconomic development(1) childhood(1) Impact(1) endemicity(1) escape mutations.(1) Therapeutic plasma exchange(1) pair(1) vaccination(1) immunization program(1) hepatitis A virus(1) Meningitis(1) multipl organ failure(1) Cystic echinococcosis(1) Seroprevalence(1)