[1] Univ Hosp Essen, Univ Duisburg Essen, Dept Pediat III, Essen, Germany
[2] Univ Hosp Dusseldorf, Heinrich Heine Univ Duesseldorf, Inst Virol, Dusseldorf, Germany
[3] Univ Hosp Dusseldorf, Heinrich Heine Univ Dusseldorf, Dept Gynecol & Obstet, Dusseldorf, Germany
[4] Univ Hosp Dusseldorf, Heinrich Heine Univ, Dept Otorhinolaryngol Head Neck Surg, Dusseldorf, Germany