title: Human parasitic protozoan infection to infertility: a systematic review.
abstract: Protozoan parasitic diseases are endemic in many countries worldwide, especially in developing countries, where infertility is a major burden. It has been reported that such infections may cause infertility through impairment in male and female reproductive systems. We searched Medline, PubMed, and Scopus databases and Google scholar to identify the potentially relevant studies on protozoan parasitic infections and their implications in human and animal model infertility. Literature described that some of the protozoan parasites such as Trichomonas vaginalis may cause deformities of the genital tract, cervical neoplasia, and tubal and atypical pelvic inflammations in women and also non-gonoccocal urethritis, asthenozoospermia, and teratozoospermia in men. Toxopalasma gondii could cause endometritis, impaired folliculogenesis, ovarian and uterine atrophy, adrenal hypertrophy, vasculitis, and cessation of estrus cycling in female and also decrease in semen quality, concentration, and motility in male. Trypanosoma cruzi inhibits cell division in embryos and impairs normal implantation and development of placenta. Decrease in gestation rate, infection of hormone-producing glands, parasite invasion of the placenta, and overproduction of inflammatory cytokines in the oviducts and uterine horns are other possible mechanisms induced by Trypanosoma cruzi to infertility. Plasmodium spp. and Trypanosoma brucei spp. cause damage in pituitary gland, hormonal disorders, and decreased semen quality. Entamoeba histolytica infection leads to pelvic pain, salpingitis, tubo-ovarian abscess, and genital ulcers. Cutaneous and visceral leishmaniasis can induce genital lesion, testicular amyloidosis, inflammation of epididymis, prostatitis, and sperm abnormality in human and animals. In addition, some epidemiological studies have reported that rates of protozoan infections in infertile patients are higher than healthy controls. The current review indicates that protozoan parasitic infections may be an important cause of infertility. Given the widespread prevalence of parasitic protozoa diseases worldwide, we suggest further studies to better understanding of relationship between such infections and infertility.
authors.affiliation: Department of Midwifery, Mazandaran University of Medical Sciences, Sari, Iran.
authors.forename: Malihe Nourollahpour
authors.initials: MN
authors.lastname: Shiadeh
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Niyyati
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran.|Razi Herbal Medicines Research Center, Lorestan University of Medical Science, Khorramabad, Iran.
authors.forename: Shirzad
authors.initials: S
authors.lastname: Fallahi
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. alirostami1984@gmail.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Rostami
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D007246:Infertility / Q000209:etiology*; D008297:Male; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic; D011528:Protozoan Infections / Q000150:complications*; D012661:Semen / Q000469:parasitology
keywords: Infections; Infertility; Protozoan parasites