Transmission of Calicophoron daubneyi and Fasciola hepatica in Galicia (Spain): Temporal follow-up in the intermediate and definitive hosts

Background Paramphistomosis caused by Calicophoron daubneyi and fasciolosis caused by Fasciola hepatica are common parasitic diseases of livestock animals. Transmission of the diseases depends on the presence of intermediate hosts, i.e. freshwater gastropods such as lymnaeids. We carried out a 2-year-long study of the dynamics of the snail population acting as the intermediate host for these parasites, considering the population structure in terms of size/age and infection status. In addition, we determined the kinetics of trematode egg excretion in grazing cows. Generalized Additive Models (GAMs) were used to analyze the associations between different response variables and snail size, sampling month and weather-related variables. Results Of the molluscan species examined, Galba truncatula, Radix peregra, Anisus (Anisus) leucostoma and Pisidium casertanum (n = 2802), only G. truncatula was infected with C. daubneyi or F. hepatica, at prevalence rates of 8.2% and 4.4% respectively. The probability of infection with C. daubneyi or F. hepatica was linearly related to snail size, although in different ways (negative for C. daubneyi and positive for F. hepatica). The total snail population increased in winter, when specimens of all size classes were found. Infected snails were more abundant during spring-autumn. Mature cercariae of both parasites were found in most seasons. In the statistical models, the sampling month accounted for a high percentage (71.9–78.2%) of the observed variability in snail abundance. The inclusion of climatic variables in the models moderately increased the percentage of deviance explained (77.7–91.9%). Excretion of C. daubneyi eggs in cow faeces was always higher than that of F. hepatica eggs. Conclusions Particular care should be taken to prevent pastures and the surrounding environment being contaminated with parasite eggs during winter-spring, when the number of snails susceptible to miracidial infections is maximal. This is therefore the optimal time for treating grazing animals. Nevertheless, control of trematodosis based only on chemotherapy is difficult in an area such as the study area, where environmental factors favour the regular appearance of snail populations harbouring mature cercariaeThe present study was financially supported by the Ministerio de Economía y Competitividad (AGL2011-30563-C03-03). The funders did not have any role in the study design, data collection and analyses, decision to publish or preparation of the manuscriptS

Paramphistomosis bovina en Galicia

Las paramphistomosis son infecciones producidas por trematodos de la familia Paramphistomidae Fischoeder, 1901, que incluye diferentes géneros y especies que parasitan el tracto gastrointestinal de rumiantes. Los animales se infectan al ingerir pastos contaminados con metacercarias producidas tras el enquistamiento de las fases larvarias emitidas por moluscos que actúan como hospedadores intermediarios. En Galicia, donde también se han detectado explotaciones con altas prevalencias de infección, se desconocían aspectos básicos sobre la epidemiología de estas parasitosis. En consecuencia, se ha realizado un amplio estudio en el que se han abordado muchos aspectos

Susceptibility of some Helicella spp. to the infection by Dicrocoelium dendriticum (Tramatoda: Dicrocoeliiidae)

Trabajo presentado al: Septième Congrès International de Malacologie (Perpignan-Banyuls, Francia, 31 de agosto al 7 de septiembre de 1980)Dicrocoelium dendriticum (Rudolphi, 1819) Looss, 1899 is a common parasite of the bile ducts of mammals, widespread all over the world...Peer reviewe

Susceptibility of some species of the genus Helicella Ferussac, 1821 (Gastropoda, Helicidae) to the infection by Dicrocoelium dendriticum (Trematoda)

4 pages, 2 tables, 2 figures.-- Proc. Seventh International Malacological Congress, Perpignan-Banyuls-sur-Mer, (France) 31 August-7 September 1980. Colloque Pathologie et Parasitologie.Three species of the genus Helicella Férussac, 1821 (H. zaratei, H. ordunensis and H. bierzona) have been tested as intermediate hosts of Dicrocoelium dendriticum under experimental conditions. The percentages of egg hatching in the midgut are similar for all three species (86.49, 82.21 and 80.20). In all three species, sporocysts were found during examination 60 days after infection, their size varying between 429.2 m and 58.0 m. According to the results it would seem that H. zaratei is a better intermediate host than the other two species. We discuss the ecological value of the species, with reference to their distribution.Peer reviewe

Helmintos y moluscos, con especial atención a la familia Helicidae

P. 525-539Basándose en investigaciones propias y en estudios bibliográficos se analiza el papel de los moluscos como hospedadores intermediarios de helmintos, concediendo particular atención a los miembros de la familia Helicidae. En sendos cuadros se recogen los trematodos y cestodos y nematodos que utilizan Helicidae en sus ciclos, indicando los hospedadores definitivos correspondientes

Parsimony methods applied to the system of Helicoidea

Trabajo presentado al 10th International Malacological Congress (Tübingen, R.F.A., 27 de agosto al 2 de septiembre de 1989).Disagreements referring to the clasification of the genera, subfamiliee and families, which form the euperfamily Helicoidea, have been pointed out lately...Peer reviewe

A tool for diagnosis of Dicrocoelium dendriticum infection: hatching eggs and molecular identification of the miracidium

7 páginas, 2 figuras, 1 tabla.-Received: 13 December 2012 / Accepted: 18 January 2013 / Published online: 6 February 2013DNA primers were designed from the 18S rRNA sequence from the relevant digenean trematode Dicrocoelium dendriticum to evaluate a polymerase chain reaction-based diagnostic method of this parasite from its eggs in faeces of naturally and experimentally infected sheep. In order to get DNA from D. dendriticum eggs, several hatching mechanisms were studied. Successful results were obtained when the eggs were frozen to -80 A degrees C and/or in liquid nitrogen and then defrosted. This method allowed the opening of the egg operculum and the liberation of the miracidium. DNA from D. dendriticum adults and from hatching egg miracidia was obtained and an amplification single band of 1.95 kb was observed using primers designed for the total 18S rRNA sequence in both cases as well as when the template DNA was from adults of the closely related parasite Fasciola hepatica; in addition, a single and specific 0.8-kb band was obtained when primers based on an internal partial 18S rRNA sequence were used. The method showed to be useful not only in samples coming from adults, but in eggs from gall bladder and faeces as well. F. hepatica internal 18S rRNA primers were also designed and used as a negative control to prove that the eggs in faeces came from D. dendriticum and not from F. hepatica. A molecular tool able to detect a minimum of about 40 D. dendriticum eggs in one of the definitive host faeces has been developed for the first time and could provide a useful molecular tool to improve the conventional coprological diagnosis for detecting D. dendriticum eggs.This work was supported by the Spanish CICYT (Project No. AGF96-0416) and Castile and León Autonomy (Proyect No. CSI5/98). H. Sandoval was supported by a Scientist Research Contract from the CSIC.Peer reviewe

Study on the experimental susceptibility of two Cernuella species (Mollusca: Stylommatophora) to Dicrocoelium dendriticum (Digenea)

1 page.-- Contributed to: World Congress of Malacology, Washington, DC, 25-30 July, 1998The small liver fluke Dicrocoelium dendriticum (Rudolphi, 1819) is the parasite responsible for sheep and cattle dicrocoeliosis in various parts of the world. Several species of land mollusks and ants are its first and second intermediate hosts, respectively. The experimental susceptibiity of two species of Cernuella (Stylommatophora) to D. dendriticum was studied to understand the natural infection data and dicroceliosis epidemiology. Two batches of 150 C. (C.) virgata (Da Costa, 1778) and 70 C. (Microxeromagna) vestita (Rambur, 1868) specimens were tested with doses of 60 and 20 D. dendriticum eggs per mollusk, respectively. These mollusks were maintained under laboratory conditions (22.2°C ± 0.18 SE; 42.4% ± 0.30 relative humidity) and killed periodically. [The following results concerning C. (C.) virgata are marked by one asterisk (*); those of C. (M) vestita by two (**).] D. dendriticum hatched eggs were observed inthe feces eliminated by 34.6%* d 357%** of the mollusks. The parasite was detected using the stereomicroscope in 36%* and 24.8%* * of the snails. The first observation of D. dendriticum (daughter sporocysts with undifferentiated germinal masses) in the mollusks was on day 61 * post-infection (p. i.) and 62* * p. i. Sporocysts with developed cercariae were observed in C. (C.) virgata from day 135p. i. until the end of the experiment (167 p.i.), while only inmature cercariae were detected in C. (M.) vestita until day 132 p.i.Supported by CICYT Ref. AGF92- 0588Peer reviewe

Dynamique de l’élimination d’œufs de Dicrocoelium dendriticum (Trematoda, Digenea) dans les fèces des ovins du Bassin de la Porma (León, Nord-Ouest de I’Espagne)

5 pages, 1 table, 2 figures.-- PMID: 1952698 [PubMed].http://www.ncbi.nlm.nih.gov/pubmed/1952698[EN] The elimination of Dicrocoelium dendriticum eggs in sheep faeces from 4 localities in the upper and middle Porma river basin was recorded at monthly intervals between March 1986 and March 1987. The faecal material was taken directly from the rectum of the animals (10 % of the flock in each village). The sedimentation technique and McMaster egg counting chambers were used to analyze the faecal samples. Of the 995 samples examined, 63.6 % contained D. dendriticum eggs and the number of eggs per gram (epg) varied from 33 to 5,340 (average 323.4 ± 18.5). The highest elimination rate was observed in winter, not only because of prevalence (90.5 %) but also because of the epg (average 726.6 ± 88.4). Prevalence of infection (from 61.5 to 65.4 %) was similar for all age groups, although the highest mean epg value (367.6 ± 50.9) was found in lambs.[FR] De mars 1986 à mars 1987, à intervalles mensuels, l’élimination d’œufs de Dicrocoelium dendriticum dans les fèces d’ovins a été mesurée dans 4 localités du bassin supérieur et central du fleuve Porma. Les matières fécales étaient prises directement au rectum des animaux (sur 10 % du troupeau d’ovins de chaque village). Les échantillons de fèces sont analysés selon la technique de sédimentation et les œufs comptés en cellule de McMaster. Des 995 échantillons examinés, 63,6 % contenaient des œufs D. dentriticum et le nombre d’œufs par gramme (opg) variait entre 33 et 5340 (moyenne 323,4 ± 18,5). Le niveau d’élimination le plus haut (prévalence et opg) était rencontré pendant I’hiver. La prévalence d’infestation (de 61,5 à 65,4 %) était similaire pour tous les groupes d’âge, bien que le niveau moyen le plus haut d’opg (367,6 ± 50,9) soit rencontré chez les agneaux.This study was supported by the Spanish CSIC (Project No. ID-608), the "Junta de Castilla y León" (Project No. 0701/89) and DGICYT (Project GAN89-0525).Peer reviewe

Coprological study of theDicrocoelium dendriticum (Digenea) egg elimination by cattle in highland areas in León Province, Northwest Spain

4 pages, 2 figures.-- PMID: 8415564 [PubMed].Dicrocoelium dendriticum egg output in cattle from five locations of the Porma river basin (León Province, Northwest Spain) was studied at monthly intervals between March 1986 and March 1987. We found D. dendriticum eggs in 37.64% of the 1251 samples examined, and the number of eggs per gram (epg) ranged from 10 to 1000 (average, 41.65 ± 2.73). The main egg elimination period, for prevalence, was autumn-winter. The average epg values were quite similar during all months except March, when the maximum was detected. The infection prevalence increased in cattle aged up to 2 years and then a slight, gradual decrease was observed with increasing host age. The average epg values ranged from 40.08 ± 3.24 to 48.33 ± 12.42 in all age groups except the oldest animals, for which the figures were lower. The rate of egg elimination was higher in animals that came from locations situated at a greater altitude.This study was supported by the Spanish CSIC (Project ID-608) and by the Junta de Castilla y León (Project 0701/89).Peer reviewe