0000000000041576
AUTHOR
M. Adela Valero
Fasciola spp: Mapping of the MF6 epitope and antigenic analysis of the MF6p/HDM family of heme-binding proteins
MF6p/FhHDM-1 is a small cationic heme-binding protein which is recognized by the monoclonal antibody (mAb) MF6, and abundantly present in parenchymal cells and secreted antigens of Fasciola hepatica. Orthologs of this protein (MF6p/HDMs) also exist in other causal agents of important foodborne trematodiasis, such as Clonorchis sinensis, Opisthorchis viverrini and Paragonimus westermani. Considering that MF6p/FhHDM-1 is relevant for heme homeostasis in Fasciola and was reported to have immunomodulatory properties, this protein is expected to be a useful target for vaccination. Thus, in this study we mapped the epitope recognized by mAb MF6 and evaluated its antigenicity in sheep. The sequenc…
Fasciola hepatica reinfection potentiates a mixed Th1/Th2/Th17/Treg response and correlates with the clinical phenotypes of anemia.
Background: Fascioliasis is a severe zoonotic disease of worldwide extension caused by liver flukes. In human fascioliasis hyperendemic areas, reinfection and chronicity are the norm and anemia is the main sign. Herein, the profile of the Th1/Th2/Th17/Treg expression levels is analyzed after reinfection, correlating them with their corresponding hematological biomarkers of morbidity. Methodology/Principal findings: The experimental design reproduces the usual reinfection/chronicity conditions in human fascioliasis endemic areas and included Fasciola hepatica primo-infected Wistar rats (PI) and rats reinfected at 8 weeks (R8), and at 12 weeks (R12), and negative control rats. In a cross-sect…
Impact of climate change and man-made irrigation systems on the transmission risk, long-term trend and seasonality of human and animal fascioliasis in Pakistan
Large areas of the province of Punjab, Pakistan are endemic for fascioliasis, resulting in high economic losses due to livestock infection but also affecting humans directly. The prevalence in livestock varies pronouncedly in space and time (1-70%). Climatic factors influencing fascioliasis presence and potential spread were analysed based on data from five mete- orological stations during 1990-2010. Variables such as wet days (Mt), water-budget-based system (Wb-bs) indices and the normalized difference vegetation index (NDVI), were obtained and correlated with geographical distribution, seasonality patterns and the two-decade evolution of fascioliasis in livestock throughout the province. …
Epidemiology and management of foodborne nematodiasis in the European Union, systematic review 2000–2016
Background: Foodborne nematodiasis are caused by the ingestion of food contaminated by helminths. In Europe, these diseases are present in all countries. Objectives: To review the available data on epidemiology and management of foodborne nematodiasis in the European Union, detect any trends and determine the possible causes of the observed changes. Methods: A review of available literature published between 2000 and 2016 was conducted. Results: Out of 1523 cases described in the literature, 1493 cases were autochthonous and 30 cases were imported. The detected parasites were Toxocara spp (34.7%), Ascaris lumbricoides (27.1%), Trichinella spp (21.9%), Anisakis spp (15.5%) and Angiostrongylu…
Domestic pig prioritized in one health action against fascioliasis in human endemic areas: Experimental assessment of transmission capacity and epidemiological evaluation of reservoir role
The Northern Bolivian Altiplano is the human fascioliasis hyperendemic area where the highest prevalences and intensities in humans have been reported. Preventive chemotherapy was implemented in the last ten years. Surveillance showed high human infection and re-infection rates in between the annual triclabendazole monodose treatments. A complementary One Health control action was launched to decrease the infection risk. Among the multidisciplinary axes, there is the need to establish animal reservoir species priorities for a more efficient control. Laboratory and field studies were performed for the first time to assess the Fasciola hepatica transmission capacity of the pig and its potenti…
Distribution of Fasciola hepatica and F. gigantica in the endemic area of Guilan, Iran: Relationships between zonal overlap and phenotypic traits
Fascioliasis is a zoonotic disease emerging in numerous parts of the world. In any endemic area, the characterisation of scenarios and patterns of infection must always be considered the starting point before implementing any control measure. Fascioliasis is a parasitic disease of different epidemiological, pathological and control characteristics depending on the endemic area and the causal agent, Fasciola hepatica and Fasciolagigantica. Classically it has been accepted that F. hepatica is present worldwide, while the distribution of the two species overlaps in many areas of Africa and Asia. Fascioliasis caused by F. hepatica, F. gigantica and intermediate forms is present in Guilan provin…
Patterns in Size and Shedding of Fasciola hepatica Eggs by Naturally and Experimentally Infected Murid Rodents
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…
Impact of fascioliasis reinfection on Fasciola hepatica egg shedding: relationship with the immune-regulatory response.
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 …
Donkey Fascioliasis Within a One Health Control Action: Transmission Capacity, Field Epidemiology, and Reservoir Role in a Human Hyperendemic Area.
A One Health initiative has been implemented for fascioliasis control in a human hyperendemic area for the first time. The area selected for this multidisciplinary approach is the Northern Bolivian Altiplano, where the highest prevalences and intensities in humans have been reported. Within the strategic intervention axis of control activities concerning animal reservoirs, complete experimental studies, and field surveys have been performed to assess the fascioliasis transmission capacity and epidemiological role of the donkey for the first time. Laboratory studies with altiplanic donkey-infecting Fasciola hepatica and altiplanic Galba truncatula snail vector isolates demonstrate that the d…
Immune suppression in advanced chronic fascioliasis: an experimental study in a rat model.
Chronicity and Th2 immune responses are features of helminth infections in humans. The liver fluke promotes its own survival through several strategies to down-regulate the immune response of the host during the early phase of infection. However, there is no evidence that this modulation occurs much later. The immune response in advanced chronic fascioliasis was analyzed in an experimental rat model at 20 weeks after infection. Cytokine quantification in infected rat serum revealed basal levels. The predominant immunoglobulin (Ig) isotype was IgG1. Flow cytometry analysis of T cell (CD3 + , CD4 + , and CD8a + ), B cell (CD45R + ), and macrophage (CD11b + ) populations in spleens showed no s…
Higher physiopathogenicity byFasciola giganticathan by the genetically closeF. hepatica: experimental long-term follow-up of biochemical markers
Background: Fascioliasis is caused by Fasciola hepatica and F. gigantica. The latter, always considered secondary in human infection, nowadays appears increasingly involved in Africa and Asia. Unfortunately, little is known about its pathogenicity, mainly due to difficulties in assessing the moment a patient first becomes infected and the differential diagnosis with F. hepatica. Methods: A long-term, 24-week, experimental study comparing F. hepatica and F. giganticawas made for the first time in the same animal model host, Guirra sheep. Serum biochemical parameters of liver damage, serum electrolytes, protein metabolism, plasma proteins, carbohydrate metabolism, hepatic lipid metabolism and…
Sheep and Cattle Reservoirs in the Highest Human Fascioliasis Hyperendemic Area: Experimental Transmission Capacity, Field Epidemiology, and Control Within a One Health Initiative in Bolivia
The Northern Bolivian Altiplano is the human fascioliasis hyperendemic area where the highest prevalences and intensities of infection by Fasciola hepatica in humans have been reported. Four animal species are the reservoir species for F. hepatica in this area, namely, sheep, cattle, pigs, and donkeys. Livestock for the Aymara inhabitants is crucial because vegetable cultures are not viable due to the inhospitality of the very high altitude of 3,820–4,100 m. A One Health initiative has been implemented in this area in recent years, as the first such control action in a human endemic area ever. Among the different control axes included, special focus is devoted to the two main reservoirs she…
CIAS detection of Fasciola hepatica/F. gigantica intermediate forms in bovines from Bangladesh
Fascioliasis is an important food-borne parasitic zoonosis caused by two trematode species, Fasciola hepatica and Fasciola gigantica. The characterisation and differentiation of Fasciola populations is crucial to control the disease, given the different transmission, epidemiology and pathology characteristics of the two species. Lineal biometric features of adult liver flukes infecting livestock have been studied to characterise and discriminate fasciolids from Bangladesh. An accurate analysis was conducted to phenotypically discriminate between fasciolids from naturally infected bovines (cattle, buffaloes) throughout the country. Morphometric analyses were made with a computer image analys…
Fluke egg characteristics for the diagnosis of human and animal fascioliasis by Fasciola hepatica and F. gigantica
In trematodiases, shape and size of the fluke eggs shed with faeces are crucial diagnostic features because of their typically reduced intraspecific variability. In fascioliasis, the usual diagnosis during the biliary stage of infection is based on the classification of eggs found in stools, duodenal contents or bile. The aim of the present study is to validate the identification of Fasciola species based on the shape and size of eggs shed by humans, characterizing their morphometric traits using a computer image analysis system (CIAS). The influence of both the geographical location and of the host (human and livestock) has been analysed. Coprological studies were carried out in fasciolias…
Assessing the validity of an ELISA test for the serological diagnosis of human fascioliasis in different epidemiological situations
Objectives To improve the diagnosis of human fascioliasis caused by Fasciola hepatica and Fasciola gigantica, we evaluated the diagnostic accuracy of an enzyme-linked immunosorbent assay (ELISA), with Fasciola antigen from the adult liver fluke, for the detection of IgG against fascioliasis in human sera. Methods The sera of 54 fascioliasis cases, originating from three endemic areas, were used in this evaluation: (i) a hyperendemic F. hepatica area where humans usually shed a great number of parasite eggs in faeces (11 sera); (ii) an epidemic F. hepatica area where humans usually shed small amounts of parasite eggs (24 sera) and (iii) an overlap area of both Fasciola species and where huma…
First morphogenetic analysis of parasite eggs from Schistosomiasis haematobium infected sub-Saharan migrants in Spain and proposal for a new standardised study methodology
International audience; Schistosomiasis is a Neglected Tropical Disease caused by trematode species of the genus Schistosoma. Both, autochthonous and imported cases of urogenital schistosomiasis have been described in Europe. The present study focuses on eggs, considered pure S. haematobium by genetic characterisation (intergenic ITS region of the rDNA and cox1 mtDNA). A phenotypic characterisation of S. haematobium eggs was made by morphometric comparison with experimental populations of S. bovis and S. mansoni, to help in the diagnosis of S. haematobium populations infecting sub-Saharan migrants in Spain. Analyses were made by Computer Image Analysis System (CIAS) applied on the basis of …
Fasciola hepatica phenotypic characterization in Andean human endemic areas: Valley versus altiplanic patterns analysed in liver flukes from sheep from Cajamarca and Mantaro, Peru
Fascioliasis is a zoonotic parasitic disease caused by Fasciola hepatica and Fasciola gigantica. Of both species, F. hepatica is the only one described in the Americas, mainly transmitted by lymnaeid snail vectors of the Galba/. Fossaria group. Human fascioliasis endemic areas are mainly located in high altitude areas of Andean countries. Given the necessity to characterize F. hepatica populations involved, the phenotypic features of fasciolid adults infecting sheep present in human fascioliasis endemic areas were analysed in the Cajamarca Valley and Mantaro Valley (valley transmission patterns) and the northern Bolivian Altiplano (altiplanic transmission pattern). A computer image analysis…
Very High Fascioliasis Intensities in Schoolchildren from Nile Delta Governorates, Egypt: The Old World Highest Burdens Found in Lowlands
Quantitative coprological analyses of children were performed in Alexandria and Behera governorates, Egypt, to ascertain whether individual intensities in the Nile Delta lowlands reach high levels as those known in hyperendemic highland areas of Latin America. Analyses focused on subjects presenting intensities higher than 400 eggs per gram of faeces (epg), the high burden cut-off according to WHO classification. A total of 96 children were found to shed between 408 and 2304 epg, with arithmetic and geometric means of 699.5 and 629.07 epg, respectively. Intensities found are the highest hitherto recorded in Egypt, and also in the whole Old World. A total of 38 (39.6%) were males and 58 (60.…
First phenotypic and genotypic description of Fasciola hepatica infecting highland cattle in the state of Mexico, Mexico
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…
Hyperendemic human fascioliasis in Andean valleys: an altitudinal transect analysis in children of Cajamarca province, Peru.
Abstract A coprological survey including 476 2–18 year old school children from six rural localities between 2627 and 3061 m altitude was performed in Cajamarca province, Peru. Prevalences of fascioliasis ranging from 6.7 to 47.7% (mean 24.4%) proved to be the highest so far recorded in that human hyperendemic area. Higher prevalences in females and in the 2–5 year old group were not significant. Intensities ranged from 24 to 864 eggs per gram (arithmetic mean: 113; geometric mean: 68), the majority shedding less than 100, and without significant differences according to gender or age group. Fasciola hepatica was the most common helminth within a spectrum of 11–12 protozoan and 9–11 helmint…
The wild boar (Sus scrofa Linnaeus, 1758) as secondary reservoir of Fasciola hepatica in Galicia (NW Spain)
Fasciolosis is an emerging or reemerging human and animal disease in numerous parts of the world. In Galicia (NW, Spain), the wild boar (Sus scrofa) is the main wild ungulate in terms of abundance and distribution. Its population has continuously increased over the past decades and this population growth has been accompanied by a reduction of habitats, so that the wild boar populations encroach more and more frequently onto agricultural lands. The increase of the interface area between livestock and the wild boars frequently involves the sharing of pastures and water sources, so that the circulation of common pathogens is propitiated. This is the first report concerning the importance of th…
Direct and indirect affection of the central nervous system by Fasciola infection
Fascioliasis is a worldwide, zoonotic disease caused by the liver trematodes Fasciola hepatica and Fasciola gigantica. Neurological fascioliasis has been widely reported in all continents, affecting both sexes and all ages. Two types of records related to two physiopathogenic mechanisms may be distinguished: cases in which the neurological symptoms are due to direct effects of a migrating juvenile present in the brain or neighboring organ and with cerebral lesions suggesting migration through the brain; and cases with neurological symptoms due to indirect immuno-allergic and toxic effects at distance from flukes in the liver. Neurological manifestations include minor symptoms, mainly cephal…
Relationships between host species and morphometric patterns in Fasciola hepatica adults and eggs from the northern Bolivian Altiplano hyperendemic region
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…