iraj sedighi department of pediatrics, school of medicine, hamedan university of medical sciences, hamedan, ir iran amir hosein zahirnia department of medical entomology, school of medicine, hamedan university of medical sciences, hamadan, ir iran; department of medical entomology, school of medicine, hamedan university of medical sciences, hamedan, ir iran. tel: +98-9188115375, fax: +98-8118234391 mojdeh afkhami department of pediatrics, school of medicine, hamedan university of medical sciences, hamedan, ir iran