fariba khoshzaban department of parasitology and mycology, faculty of medical sciences, shahed university, tehran, ir iran; department of parasitology and mycology, faculty of medical sciences, shahed university, tehran, ir iran. tel: +982188964792, fax: +982188966310 fatemeh ghaffarifar department of parasitology, faculty of medical sciences, tarbiat modares university, tehran, ir iran hamid reza jamshidi koohsari department of parasitology and mycology, faculty of medical sciences, shahed university, tehran, ir iran