Background: Blastocystis hominis is recognized as a common intestinal parasite. Some studies have reported the effect of phenotypic, serologic, and biochemical indices on the parasites’ pathogenic characteristics. Objectives: This study aimed to introduce B. hominis as a pathogen, trying to change views about this parasite and introduce it as a parasite important in medical sciences. Methods: An open-ended, language-restricted (English) search was conducted in MEDLINE (PubMed), CINAHL, Scopus, and the Cochrane Library databases (from 1990 to 2018) using specific search criteria to identify Blastocystis spp. Results: The search of the literature retrieved 158 published articles on Blastocystis spp. Among these articles, the ones related to the pathogenicity of B. hominis were selected for further investigations. Results obtained in this study showed that the number of articles within five-year periods had an increasing trend. Also, studies of B. hominis have mainly investigated its pathogenic characteristics, accounting for 37. 34% of the studies. Conclusions: This study showed comprehensive reasons for proving the pathogenesis of the parasite. It is hoped that further studies would fill the existing gaps regarding this parasite and identify its true identity as a medically important parasite.

During 1998, a survey was carried out to collect and identify terrestrial Parasitengona mites associated with short-horned grasshoppers (Acrididae) in Karaj and Varamin, north- central regions of Iran. Samples of grasshoppers were taken twice a month from these regions. They were examined in laboratory for mites associated with them. In this study three new species of subfamily Callidosomatinae, genus Charletonia Oudemans, 1910 were collected and identitied as follows: The species C. damavandica sp. nov.on Acrotylus insubricus Scop. And Mioscirus wagneri Kitt. From Varamin; C. nazeleae sp. nov. on Heliopteryx humeralis Kuthy and Palasiella turcomana F-W. from Karaj: and C. saboorii sp. novo on Heteracris littoralis similis (Br.-W.) from Varamin. Type specimens were deposited to insects and mites collection, College of Agriculture, Tarbiat Modarres University, Tehran, Iran.