frequency of intestinal parasites in tehran

background: for a long time, intestinal parasite infections are among the major problems of public health in iran. our aim was epidemiological studies on the frequency of intestinal parasites in patients re­ferred to three hospitals in tehran during 2007-2008. methods : during 2007-2008, by simple random selection, 1000 stool samples were collected from mi­lad, hazrat-e-rasoul and shahid fahmideh hospitals in tehran, iran. we examined the samples using di­rect smear, formol-ethyl acetate concentration, agar-plate culture and ziehl-neelsen staining tech­nique. results : the frequency of intestinal parasites were: blastocystis hominis 12.8%, giardia lamblia 2.5%, en­tamoeba coli 4.8%, iodamoeba butschlli 0.9%, unknown 4 nuclei cysts 0.4%, endolimax nana 3.2%, chilomastix mesnili 0.4%, strongyloides stercoralis 0.1%, hymenolepis nana 0.2% and taenia sagi­nata 0.2%. coccidian parasites were not found. results show that infection with intestinal parasites does not statistically significant according to sex and age. conclusion: the intestinal parasites, especially helminthic infections have been decreased during re­cent years.