Sexual transmission of American trypanosomiasis in humans: a new potential pandemic route for Chagas parasites

Abstract

BACKGROUND The Trypanosoma cruzi infection endemic in Latin America has now spread to several countries across four continents; this endemic involves triatomine vector-free protists. We hypothesised that the sexual transmission of T. cruzi contributes to the ongoing spread of Chagas disease.OBJECTIVES A short-term longitudinal study was conducted to evaluate this hypothesis.METHODS The study population comprised 109 subjects from four families, among whom 21 had been diagnosed with acute Chagas disease by direct parasitological analysis. Blood mononuclear cells and serum samples were obtained from each study subject once per year for three consecutive years. Enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence serological examinations were used to detect specific T. cruzi antibodies. Polymerase chain reaction of T. cruzi DNA revealed 188-nucleotide bands, which hybridised to a specific radiolabelled probe and were confirmed by cloning and sequencing.RESULTS Three independent assessments at different time points revealed T. cruzi nuclear DNA footprints in 76% (83/109) of the study population with active infection. In contrast, the ELISA and indirect immunofluorescence assays detected the T. cruzi antibody in 28.4% (31/109) of the study samples. Moreover, the semen from 82.6% (19/23) of subjects people revealed harboured the 188- bp base pair T. cruzi footprint. Interestingly, the ejaculates of nuclear DNA-positive Chagas patient transmitted the T. cruzi upon peritoneal injection or infusion in the vagina of mice, and amastigotes were detected in the skeletal muscle, myocardium, vas deferens, and uterine tube.MAIN CONCLUSIONS T. cruzi infections can be transmitted from females or males to naïve mates through intercourse, and progeny showed discrepancies between the ratios of nuclear DNA footprints and specific antibody that can be explained by the tolerance attained during early embryo growth. Additional studies are needed to develop drugs to eradicate the infections. Additionally, the importance of a vigorous education, information, and communication program to prevent sexually transmitted Chagas disease in humans cannot be underemphasised.

Thiol efflux mediated by an ABCC-like transporter participates forTrypanosoma cruziadaptation to environmental and chemotherapeutic stresses

“…Alternatively, T. cruzi may be transmitted by the consumption of food contaminated with vector feces or with the secretion of infected mammals (4), donation of blood, organs or tissues, especially in countries that do not screen samples for T. cruzi (5), and during pregnancy (6). Furthermore, sexual transmission (7,8) and other species as potential vectors (9) show up as possible routes for spreading of disease mainly in nonendemic areas.…”

Noninvasive Biological Samples to Detect and Diagnose Infections due to Trypanosomatidae Parasites: A Systematic Review and Meta-Analysis

“…Chagas Disease. The main transmission route of T. cruzi is via reduviids, but sexual and transplacental transmission have been described and have epidemiological relevance [317,318]. In 1911, Vianna described testis lesions in experimentally T. cruzi-infected guinea pigs [319].…”

“…In females, T. cruzi invades cells of the vagina, uterus, oviduct, ovary, and clitoris [313,315]. In addition, T. cruzi DNA has been detected in the semen of patients suffering from Chagas disease [317,324]. Limited data exist for humans, but the presence of T. cruzi was reported in seminiferous tubules and ovarian cells of children who succumbed to Chagas disease and in menstrual blood of infected patients [30,325].…”

Evidence for Previously Unidentified Sexual Transmission of Protozoan Parasites

“…Our search resulted in 5 parasite species with demonstrated presence in seminal fluid of humans: Entamoeba hystolytica ( 3 ), Schistosoma haematobium ( 4 ), Trichomonas vaginalis ( 2 ), Trypanosoma cruzi ( 5 ), and Toxoplasma gondii ; the latter has been documented as sexually transmitted among animals, but not humans ( 6 ) (Table). E .…”

“…Parasitic involvement of the male genital tract, alteration in semen characteristics ( 7 ), and the presence of the parasite’s DNA in semen have recently been identified in chronically infected patients ( 5 ) . Furthermore, an experimental mouse model has demonstrated infection through intravaginal infusion of semen from infected humans, posing the possibility of sexual transmission among humans ( 5 ). …”