Schistosomiasis and Infertility: What Do We Know?

There is increasing attention on the complex interactions occurring between schistosome parasites and their hosts. However, little is known about the occurrence, epidemiology, and mechanisms of schistosomiasis-associated infertility. In this article, we argue that an in-depth understanding of the interplay between parasites and the host endocrine system may significantly enhance current knowledge of infertility in infected individuals. We discuss the basic hormonal mechanisms that may lead to the discovery of entirely novel anthelmintic interventions against schistosomiasis.

[Neuroendocrine effects of helminthiases (A review)].

Nowadays the number of patients diagnosed with helminthiases shows tendency for steady growth around the world. During last few years, researches in the field of immunology have again turned their attention towards the question of parasitological immunity and tissue response. Helminthiases and other parasitic diseases in some instances can induce central nervous system disorders and violate human behavioral reactions. Studies have suggested an association between epilepsy and helminth infection, but a causal relationship is not established in many helminths, except perhaps with neurocysticercosis. The aim of this review is to reveal details of specific mechanisms of the general helminths' impact on the nervous system and the endocrine control level of physiological functions of the host organism. Finally, we discuss the current gaps in knowledge about the interaction between helminths, immunity, and human endocrine system. Key words: helminths, immunity, hormones, cytokines.

Nancy E. Beckage (1950-2012): pioneer in insect host-parasite interactions.

Nancy E. Beckage is widely recognized for her pioneering work in the field of insect host-parasitoid interactions beginning with endocrine influences of the tobacco hornworm, Manduca sexta, host and its parasitoid wasp Apanteles congregatus (now Cotesia congregata) on each other's development. Moreover, her studies show that the polydnavirus carried by the parasitoid wasp not only protects the parasitoid from the host's immune defenses, but also is responsible for some of the developmental effects of parasitism. Nancy was a highly regarded mentor of both undergraduate and graduate students and more widely of women students and colleagues in entomology. Her service both to her particular area and to entomology in general through participation on federal grant review panels and in the governance of the Entomological Society of America, organization of symposia at both national and international meetings, and editorship of several different journal issues and of several books is legendary. She has left behind a lasting legacy of increased understanding of multilevel endocrine and physiological interactions among insects and other organisms and a strong network of interacting scientists and colleagues in her area of entomology.

Neospora caninum and coxiella burnetii seropositivity are related to endocrine pattern changes during gestation in lactating dairy cows.

Q fever is a zoonotic infection caused by Coxiella burnetii that is endemic worldwide. Domestic ruminants are a source of infection for humans. Given the suggestion that the bacterium recrudesces during pregnancy in cattle, this study was designed to determine whether C. burnetii infection affects hormonal patterns, such as progesterone, cortisol, pregnancy associated glycoproteins (PAG), and prolactin during gestation in lactating cows. Possible interactions with Neospora caninum were also explored. The study was performed on 58 gestating non-aborting cows. Blood samples for hormone determinations were collected on Days 40, 90, 120, 150, 180, and 210 of gestation. For antibody determinations, blood was collected at day 40 postinsemination and postpartum. By GLM repeated measures analysis of variance, we established the effects of production and reproductive variables as well as Coxiella and Neospora seropositivity related to changes on cortisol, PAG, progesterone, and prolactin levels. Coxiella antibody levels were significantly related to cortisol, PAG, and plasma progesterone concentrations, whereas Neospora seropositivity was linked to plasma progesterone concentrations. The interaction between Coxiella and Neospora seropositivity was correlated with cortisol and plasma progesterone levels, whereas the interaction seropositivity against C. burnetii-plasma cortisol concentration was related to plasma PAG levels. Finally, an effect of lactation number only was observed on plasma prolactin. Our findings suggest that both the N. caninum and C. burnetii infection or the presence of both modify endocrine patterns throughout gestation. Cows seropositive to both, Neospora and Coxiella, showed higher plasma progesterone levels than the remaining animals examined. Seropositivity to C. burnetii was associated with placental damage and diminishing PAG levels throughout the second half of gestation, along with increased plasma cortisol levels on Day 180 of gestation.

Endocrine effects of the tapeworm Ligula intestinalis in its teleost host, the roach ( Rutilus rutilus).

The effects of parasite infection by the cestode Ligula intestinalis on the reproductive function and endocrine system of wild roach Rutilus rutilus were evaluated. Gonad maturation, plasma vitellogenin, plasma steroid concentrations (i.e. progesterone, 11-keto-testosterone and 17-beta-estradiol) and brain aromatase activity were investigated in relation with parasitization. A low prevalence (8%) of ligulosed roach and a moderate impact of parasitization (mean parasitization index of 8.8%) were found in the studied population. Inhibition of gonad maturation generally resulted from infestation but 5% of the ligulosed roach nevertheless reached maturity. Main sex steroid plasma content was depleted in both genders. Male 11-keto-testosterone, female 17-beta-estradiol and progesterone plasma concentrations of both genders were, respectively, 27, 5 and 3 times lower in ligulosed fish when compared to their non-infected counterparts. Progesterone levels were negatively correlated with the parasitization index in females. Brain aromatase activity of infected roach was reduced to 50% of that of the non-infected fish. These results demonstrate significant negative effects on the reproductive function of wild roach infected by the tapeworm L. intestinalis collected from a site with low contamination.