abolghasem siyadatpanah faculty of paramedical science, mazandaran university of medical sciences, sari, ir iran fatemeh tabatabaei department of parasitology and mycology, tehran university of medical sciences, tehran, ir iran amir emami zeydi department of nursing, faculty of nursing and midwifery, mazandaran university of medical sciences, sari, ir iran; faculty of nursing and midwifery, mashhad university of medical sciences, mashhad, ir iran adel spotin department of parasitology and mycology, shahid beheshti university of medical sciences, tehran, ir iran; student research committee, shahid beheshti university of medical sciences, tehran, ir iran vahid fallah-omrani department of parasitology and mycology, shahid beheshti university of medical sciences, tehran, ir iran; department of parasitology and mycology, shahid beheshti university of medical sciences, tehran, ir iran. tel: +98-9117333391, fax: +98-2172019014 mehrdad assadi department of microbiology, faculty of medicine, tabriz branch, islamic azad university, tabriz, ir iran