Background : Parasites are important enteric pathogens among patients with immunodeficiency virus (HIV) infection. In our country there are very few reports on prevalence of intestinal parasites among these patients.

Materials and methods : In the present study we have determined the prevalence of intestinal parasites among HIV-positive individuals visited in different medical centers in Iran . Single stool samples were collected and analyzed for various intestinal parasites from 206 HIV-positive individuals with different immune status. The data were tested for statistical significance with χ² and Mann-Whitney U tests.

 Results : The overall prevalence of intestinal parasites was 18.4% (95%CI: 13.7-24.3). In particular, the following parasites were identified: Giardia lamblia (7.3%), Blastocystis hominis (4.4%), Entamoeba coli (3.9%), and Cryptosporidium parvum (1.5%). Strongyloides stercoralis and Hymenolepis nana were also found in two cases and Dicrocoelium dendriticum in one. Intestinal parasites were significantly more common among patients with diarrhea (n=28) than those without (n=178) (p<0.001). Besides, CD4 counts were significantly lower among individuals with diarrhea than those without (p<0.001).

 Conclusions: This study highlights the importance of testing for intestinal parasites among Iranian HIV-positive patients especially those with low immunity presented with diarrhea.