[1] Hosp Medina del Campo, Serv Microbiol & Parasitol, Medina Del Campo 47400, Spain
[2] Hosp Clin Univ Valladolid, Serv Endocrinol & Nutr, Valladolid, Spain
[3] Hosp Clin Univ Valladolid, Ctr Salud Cartama Estac, Valladolid, Spain
[4] Hosp Clin Univ Valladolid, Serv Microbiol & Immunol, Valladolid, Spain
[5] Univ Valladolid, Fac Med, Area Pediat, Valladolid, Spain
[6] Univ Valladolid, Hosp Clin, Valladolid, Spain