RESUMEN
Background: Blastocystis is a zoonotic protozoan parasite habit in intestinal tract of humans and wide range of animals. Because of the mysterious nature and unknown or less-known aspects of Blastocystis, comprehensive information about epidemiology of this parasite is not available. The objective of this study was to investigate the available parasitology studies during the last decade in Iran and determine the prevalence of Blastocystis and its position among other intestinal parasites. As well as, investigate the effective factors in its prevalence.
Materials and Methods: All available studies related to the prevalence of intestinal parasites in Iran during the recent decade were collected using information databases. After determinant the mean prevalence of each parasite, the most common parasites, and effective factors on their prevalence were assessed and analyzed.
Results: Different studies showed that the most common intestinal parasite at this period of time was Blastocystis spp. with 14.6% prevalence rate. Additionally, in 44.5% of cases Blastocystis spp. allocated the first and in 100% of cases, the first to third rank of the most common intestinal parasites in Iran. Giardia lamblia and Entamoeba coli were in the next category.
Conclusion: To our knowledge, the present study is the first survey in which the Blastocystis spp. introduces as one of the most common intestinal parasites in human. Various factors, including the low sensitivity of routine diagnostic methods, hosts multiplicity, easy transportation and unknown impressive factors are effective in the increased prevalence of this parasite. The results of this study could improve the attitude of teachers and researchers towards Blastocystis spp.
RESUMEN
There are some genetic differences in Blastocystis that show the existence of species or genotypes. One of these genes that help in identifying Blastocystis is SSUrRNA. The aim of this study was assessment of genetic diversity of Blastocystis by PCR with seven pairs of STS primers. This study was done on 511 stool samples collected from patients referred to the health care centers of Khorramabad, Central Iran, in 2012. Ge-nomic DNA was extracted and in order to determine the Blastocystis subtype in contaminated samples, seven pairs of primers STS [subtype specific sequence-tagged site] were used. Out of 511 samples, 33 [6.5%] samples were infected with Blastocystis. Subtype [ST] of 30 samples was identified and three subtypes 2, 3 and 4 were determined. Mix infection was reported 10% which 3.33% of the infection was for the mixture of ST 3 and ST5 and 6.67% was for the mixture of ST 2 and ST 3. The predominant subtype was ST3 that is the main human subtype. The dominance of ST2 and 5 are important in this study. This superiority has been reported in some of the studies in ST 2 which is different from the studies in other countries, because they have announced priorities of the ST1 and ST6 after ST3