Please cite this article in press as: Dinleyici EC, et al. Children with breakthrough varicella infection requiring hospitalization in Turkey (VARICOMP Study 2008–2013). Vaccine (2015), http://dx.doi.org/10.1016/j.vaccine.2015.06.029 ARTICLE IN PRESS G Model JVAC-16569; No. of Pages 5 Vaccine xxx (2015) xxx–xxx Contents lists available at ScienceDirect Vaccine j our na l ho me page: www.elsevier.com/locate/vaccine Children with breakthrough varicella infection requiring hospitalization in Turkey (VARICOMP Study 2008–2013) Ener Cagri Dinleyici a,∗ , Zafer Kurugol b , Ates Kara c , Hasan Tezer d , Mehmet Ali Tas e , Ekrem Guler f , Olcay Yasa g , Ilker Devrim h , Ergin Ciftci i , Halil Ozdemir i , Ayper Somer j , Metehan Ozen k , Gulnar Sensoy l , Nazan Dalgic m , Emre Alhan n , VARICOMP Study Group 1 a Eskisehir Osmangazi University, Faculty of Medicine, Department of Pediatrics, Eskisehir, Turkey b Ege University, Faculty of Medicine, Department of Pediatrics, ˙ Izmir, Turkey c Hacettepe University, Faculty of Medicine, Department of Pediatrics, Ankara, Turkey d Gazi University, Faculty of Medicine, Department of Pediatrics, Ankara, Turkey e Dicle University, Faculty of Medicine, Department of Pediatrics, Diyarbakir, Turkey f Sutcu Imam University, Faculty of Medicine, Department of Pediatrics, Kahramanmaras, Turkey g Department of Pediatrics, Goztepe Training and Research Hospital, SB Istanbul Medeniyet University, Istanbul, Turkey h Department of Pediatrics, Dr. Behc ¸ et Uz Children’s Hospital, ˙ Izmir, Turkey i Ankara University, Faculty of Medicine, Department of Pediatrics, Ankara, Turkey j Istanbul University, Istanbul Faculty of Medicine, Department of Pediatrics, Istanbul, Turkey k Acibadem University, Faculty of Medicine, Department of Pediatrics, Istanbul, Turkey l 19 Mayis University, Faculty of Medicine, Department of Pediatrics, Samsun, Turkey m Department of Pediatrics, Sisli Etfal Training and Research Hospital, Istanbul, Turkey n Cukurova University, Faculty of Medicine, Department of Pediatrics, Adana, Turkey a r t i c l e i n f o Article history: Received 22 November 2014 Received in revised form 1 June 2015 Accepted 4 June 2015 Available online xxx Keywords: Varicella Chickenpox Varicella vaccine Breakthrough varicella a b s t r a c t Introduction: Varicella in previously immunized individuals, known as “breakthrough varicella”. While the majority of breakthrough cases are mild, some may be severe, requiring hospitalization in previously healthy children or children with an underlying condition. Methods: This report, as a part of the prospective national pediatric varicella hospitalizations study (including 29 centers, represent 50% of pediatric population) in Turkey, is aimed to evaluate breakthrough varicella infection requiring hospitalization before the routine use of single-dose live varicella vaccine in national program from 2008 to 2013 (<10% of the pediatric age group received a single-dose vaccine). Results: In the time period, 1939 children were hospitalized due to varicella infection in Turkey; 36 children (20 boys, 16 girls, mean age 68.0 + 37.6 months, all received single dose live varicella vaccine) with breakthrough varicella infection. Breakthrough varicella infection might be severe in previously healthy children (61.1%) and children with immune-compromising conditions (38.9%). The time elapsed between vaccination and hospitalization was approximately 5 years, and neurological complications, mainly encephalitis and meningitis, were the most common reason for hospitalization in previously healthy children. Conclusion: Pediatric breakthrough varicella requiring hospitalization have been seen in Turkey, is mainly observed in previously healthy children at 5 years after a single-dose varicella vaccine. The varicella vaccine has been implemented as part of the National Immunization Program in Turkey in 2013 (a single dose at age 12 months). Further surveillance in the same settings could evaluate the effectiveness of national immunization with single-dose varicella vaccine at 12 months of age and potential need for second dose of vaccine. © 2015 Elsevier Ltd. All rights reserved. ∗ Corresponding author at: Eskisehir Osmangazi University, Faculty of Medicine, Department of Pediatrics, Eskisehir TR26480, Turkey. Tel.: +90 222 23929279. E-mail address: timboothtr@yahoo.com (E.C. Dinleyici). 1 VARICOMP Study Group Members: Canan Kuzdan, Suleyman Nuri Bayram, Nihan Uygur-Kulcu, Cigdem Sag, Cagatay Nuhoglu, Ozge Metin, Meda Kondolot, Anıl Tapisiz, Solmaz Celebi, Mustafa Hacimustafaoglu, Saadet Akarsu, Denizmen Aygun, Fatih Akin, Murat Elevli, Sevtap Velipasalioglu, Selim Oncel, Melike Emiroglu, Adem Karbuz, Ozden Turel, Necdet Kuyucu, Mehmet Ceyhan, Dilek Yılmaz-Ciftdogan, Nevin Hatipoglu, Omer Kilic, Rengin Siraneci, Ahu Kara, Hursit Apa, Belgin Gulhan, Aslinur Parlakay, Emine Kocabas, Aysu Say, Nursen Belet, Ayse Baktır, Arzu Karli, Gonul Tanır, Erdal Ince, Berna Bal, Aybuke Akaslan, Yalcin Goksugur, Emin Sami Arisoy, Sami Hatipoglu. http://dx.doi.org/10.1016/j.vaccine.2015.06.029 0264-410X/© 2015 Elsevier Ltd. All rights reserved.