hossein hooshyar dept. of parasitology, school of medicine, kashan university of medical sciences, kashan, iran. parvin rostamkhani dept. of parasitology, school of medicine, kashan university of medical sciences, kashan, iran. mostafa rezaeian dept. of medical parasitology and mycology, school of public health, tehran university of medical sciences, tehran, iran and center for research of endemic parasite of iran (crepi), tehran university of medical sciences, tehran, iran.