Summary We investigated the prevalence of intestinal protozoan parasites in patients with
gastrointestinal complaints in medical centers in Zahedan, Iran. total of 1562 stool samples
was examined from July 2004 to January 2006 using microscopy (direct smear, formalin-ether
concentration)xenic culture and PCR techniques. Four hundred and twenty-seven (27.3%of
the patients were infected with one or more intestinal parasites. Giardia lamblia (10.1%)Enta-
moeba coli (10%)E. hartmanni (1.7%)Blastocystis hominis (2.2%)Chilomastix mesnili (1.7%)
Trichomonas hominis (0.7%)E. histolytica/E. dispar (0.51%and Iodamoeba butschlii (0.45%
were the most prevalent protozoa detected with microscopy. Of the eight microscopy-positive
E. histolytica/E. dispar samples, six were identified as E. dispar by PCR/gel electrophore-
sis, whereas E. histolytica was not detected at all. Although Zahedan is an area with poor
hygiene located in tropical area near the border of Pakistan and Afghanistan, the prevalence
of E. histolytica and E. dispar here compared with other parasites and infectious diseases is
unexpectedly low.
