Search results for "liver fluke"
showing 10 items of 30 documents
Impact of fascioliasis reinfection on Fasciola hepatica egg shedding: relationship with the immune-regulatory response.
2019
Abstract Fascioliasis is a disease caused by liver flukes. In human fascioliasis hyperendemic areas, reinfection and chronicity are the norm. Control strategies in humans require the use of egg count techniques to calculate the appropriate treatment dose for colic risk prevention. The present study investigates how fascioliasis reinfection affects liver fluke egg shedding and its relationship with the immune-regulatory response. The experimental design reproduced the usual reinfection/chronicity conditions in human fascioliasis endemic areas and included Fasciola hepatica primo-infected Wistar rats (PI) and rats reinfected at 4 weeks (R4), 8 weeks (R8), 12 weeks (R12), and negative control …
First phenotypic and genotypic description of Fasciola hepatica infecting highland cattle in the state of Mexico, Mexico
2018
Abstract Fascioliasis is a plantborne and zoonotic parasitic disease caused by fasciolid liver flukes. Fasciola hepatica is the only fasciolid species described in the Americas. Human fascioliasis endemic areas are mainly located in high altitude areas of the Americas. Given the necessity to characterize F. hepatica populations involved, the phenotypic and genotypic features of fasciolid adults infecting cattle in the highland area of Toluca, State of Mexico, Mexico, were analyzed and compared to fasciolid materials from the Northern Bolivian Altiplano, representing the altiplanic transmission pattern in a hyperendemic scenario. A computer image analysis system (CIAS) was applied on the bas…
On the presence and immunoregulatory functions of extracellular microRNAs in the trematode Fasciola hepatica.
2017
Summary Liver flukes represent a paraphyletic group of endoparasitic flatworms that significantly affect man either indirectly due to economic damage on livestock or directly as pathogens. A range of studies have focussed on how these macroscopic organisms can evade the immune-system and live inside a hostile environment such as the mammalian liver and bile-ducts. Recently, microRNAs, a class of short non-coding gene-regulators, have been proposed as likely candidates to play roles in this scenario. MicroRNAs (miRNAs) are key players in development and pathogenicity and are highly conserved between metazoans: identical miRNAs can be found in flatworms and mammalians. Interestingly, miRNAs a…
Hyperendemic fascioliasis associated with schistosomiasis in villages in the Nile Delta of Egypt.
2003
Coprologic surveys were carried out in villages of the Behera Governorate in the Nile Delta region of Egypt to characterize the epidemiologic features of human fascioliasis caused by Fasciola hepatica and F. gigantica in this lowland endemic area by comparison with fascioliasis caused by only F. hepatica in areas hyperendemic for human disease in the Andean highlands of South America. The fascioliasis prevalences detected (range = 5.2-19.0%, mean = 12.8%) are the highest obtained in Egypt. The comparison with previous results suggests that in the Nile Delta, fascioliasis is spreading from an original situation of sporadic human cases in well-known endemic foci for animal disease to an endem…
The Extracellular Vesicles of the Helminth Pathogen, Fasciola hepatica : Biogenesis Pathways and Cargo Molecules Involved in Parasite Pathogenesis
2015
Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterisation of the total secretome of this zoonotic parasite. Fasciola secretes at least two sub-populations of EVs that differ according to size, cargo molecules and site of release from the parasite. The larger EVs are released from the specialised cells that line the parasite gastrodermus and contain the zymogen of the 37 kDa cathepsin L peptidase that performs a digestive function. The smaller exosome-like vesicle population originate from multivesicular bodies with…
Fascioliasis in Llama, Lama glama, in Andean Endemic Areas: Experimental Transmission Capacity by the High Altitude Snail Vector Galba truncatula and…
2021
Simple Summary The infection by the liver fluke Fasciola hepatica in South American camelids, mainly llamas and alpacas, has been the focus of many studies. However, their capacity to participate in the transmission of the disease and their potential reservoir role in human or animal endemic areas have never been studied. Therefore, all development stages of an isolate from Argentine llama of the high Andean plateau have been experimentally investigated, from egg embryogenesis to metacercarial infectivity, by using the vector snail Galba truncatula from the high altitude Bolivian Altiplano human hyperendemic area. Although eggs shed by llamas may successfully develop until the adult stage i…
Relationships between host species and morphometric patterns in Fasciola hepatica adults and eggs from the northern Bolivian Altiplano hyperendemic r…
2001
The highest prevalences and intensities of human fasciolosis by Fasciola hepatica are found in the northern Bolivian Altiplano, where sheep and cattle are the main reservoir host species and pigs and donkeys the secondary ones. Morphometric comparisons of many linear measurements, areas and ratios of F. hepatica adults (from sheep, cattle and pigs) and eggs (from sheep, cattle, pigs and donkeys) in natural liver fluke populations of the Bolivian Altiplano, as well as of F. hepatica adults and eggs experimentally obtained in Wistar rats infected with Altiplanic sheep, cattle and pig isolates, were made using computer image analysis and an allometric model. Although morphometric values of adu…
Developmental differences in the uterus of Fasciola hepatica between livestock liver fluke populations from Bolivian highlands and European lowlands
2001
A morphometric study of the uterus area (UA) of Fasciola hepatica adults was carried out with the aid of a computer linked to a stereomicroscopic 3CCD colour video camera using image analysis software. The UA of adult liver flukes found in naturally infected sheep, cattle and pig from the endemic human fascioliasis zone of the northern Bolivian Altiplano highlands was compared with that of flukes found infecting sheep and cattle from Valencia, Spain and cattle from Corsica, France (collectively, European lowlands). Liver fluke UA was examined using an allometric model. A comparison of the allometry of the liver fluke UA in different host species from Bolivia revealed no significant differen…
Patterns in Size and Shedding of Fasciola hepatica Eggs by Naturally and Experimentally Infected Murid Rodents
2002
Using samples collected on the island of Corsica, a comparative study was done of the morphometry of Fasciola hepatica eggs shed by cattle and by naturally and experimentally infected murid rodents (wild Mus musculus and Rattus rattus and Rattus norvegicus Wistar laboratory strain). Eggs shed by murids are smaller in size than those shed by naturally infected cattle. A second study analyzed the number of F. hepatica eggs shed in murid feces at different time intervals, i.e., months, days, and 6-hr periods, by the Kato-Katz technique. Both experimentally and naturally infected black rats (R. rattus) were used, and Wistar rats were experimentally infected and included for comparison. The pres…
Phenotypic analysis of adults and eggs of Fasciola hepatica by computer image analysis system
2005
AbstractKnowledge of the morphological phenotypes of the liver fluke Fasciola hepatica (Trematoda: Digenea) is analysed. The influence of parasite age on its dimensions, the adult fluke growth model, variation in a biometric variable versus time, and variation in a biometric variable versus another biometric variable (allometric model) are revised. The most useful allometric model appears to be (y2m]#x2212;y2)/y2=c [(y1m−y1)/y1]b, where y1=body area or body length, y2=one of the measurements analysed, y1m, y2m=maximum values towards which y1 and y2, respectively, tend, and c, b=constants. A method based on material standardization, the measurement proposal and allometric analysis is detaile…