[1] Charles Univ Prague, Dept ENT, Fac Med 2, Univ Hosp Motol, Prague 15006 5, Czech Republic
[2] Charles Univ Prague, Univ Hosp Motol, Fac Med 2, Dept Paediat, Prague, Czech Republic
[3] Hosp Rudolph & Stephanie, Dept Otorhinolaryngol, Benesov, Czech Republic
[4] Charles Univ Prague, Dept Microbiol & Immunol, Gen Fac Hosp, Fac Med 1, Prague, Czech Republic
[5] Charles Univ Prague, Inst Med Biochem & Lab Med, Gen Fac Hosp, Fac Med 1, Prague, Czech Republic
[6] Charles Univ Prague, Dept Otorhinolaryngol & Head & Neck Surg, Univ Hosp Motol, Fac Med 1, Prague, Czech Republic
[7] Charles Univ Prague, Mil Univ Hosp, Fac Med 3, Dept ENT, Prague, Czech Republic