Frequency of Intestinal Parasites in Patients With Gastrointestinal Disorders, in Different Parts of Iran During 2012-2013

Background: Intestinal parasites of humans are one of the most important health problems worldwide, especially those located in tropical and subtropical areas. Objectives: The aim of this study was to determine the frequency of intestinal parasites in patients with gastrointestinal disorders, in different parts of Iran. Patients and Methods: A total of 1520 stool samples were collected from patients with gastrointestinal disorders. The stool specimens were examined by direct wet mount, formalin-ether concentration and a modified version of the Ziehl-Neelsen staining technique. Amoeba-positive samples were cultured for further differentiation of Entamoeba histolytica, E. dispar, E. moshkovskii. DNA-based methods were used to differentiate these amoebas and to detect Cryptosporidium- positive samples. Statistical analysis was carried out by SPSS ver. 16. Results: Out of the 1520 individuals studied, 153 (10.06%) were infected at least with one intestinal parasite. 781 (51.4%) of patients were male and 738 (48.6%) were female. The prevalence of protozoan parasites 148 (9.7%) was significantly higher than helminth parasites 5 (0.3%) (P < 0.001). The frequency of intestinal parasites was as follows: Blastocystis sp., 72 (4.73%); Giardia intestinalis, 35 (2.30%); Entamoeba coli 21 (1.38%); Endolimax nana 10 (0.92%); Cryptosporidium spp., 1 (0.06%); Entamoeba dispar, 1 (0.06%); Dientamoeba fragilis, 1 (0.06%); Hymenolepis nana, 3 (0.19%); Dicrocoelium dendriticum, 2 (0.13%). In five (0.32%) of the positive samples, co-infections with two parasites were found. G. intestinalis was more prevalent in male 22/35 (62.86%) than female 13/35 (37.14%) as well as in 0-9 years old group. In one sample Heterodera ova contained larva were seen. Conclusions: Blastocystis and G. intestinalis were the predominant intestinal parasites detected in patient with gastrointestinal disorders. The results indicated that the intestinal parasites, particularly helminth infections have been significantly declined in recent years.