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Limoges, France

Four geographical strains of Galba truncatula living on riverbanks (the first on a sedimentary soil and the other three on an acid soil) were subjected to bimiracidial exposures with Fasciola hepatica to study their aptitude for cercarial shedding and to count metacercariae in snails dissected at day 42 post-exposure. All snails were reared in 14-cm Petri dishes at 24 °C, with the same spring water (60-73 mg/l of Ca2+) and the same diet (grass and lettuce leaves). Metacercariae of F. hepatica were noted in the four populations after a cercarial shedding or after snail dissection. However, in spite of the breeding method used, the characteristics of snail infections varied with the origin of each geographical strain. For example, the shell heights of infected snails at day 42 were close to those found for the corresponding adults in the field (6.8-8.0 mm for the population living on the sedimentary soil, but only 4.6-5.5 mm for another strain originating from the acid soil). This variability may be explained by assuming that the diet of these riverbank G. truncatula would be different from that of snails living in swampy meadows. However, another hypothesis based on the influence of snail habitat on the characteristics of snail life cannot be excluded. Source

Traore S.G.,University dAbobo Adjame | Odermatt P.,Swiss Tropical and Public Health Institute | Odermatt P.,University of Basel | Bonfoh B.,Center Suisse Of Recherches Scientifiques En Cote Divoire | And 7 more authors.
Parasites and Vectors

Background: Paragonimiasis is a neglected tropical disease caused by an infection with lung flukes that is transmitted through the consumption of undercooked crabs. The disease is often confused with tuberculosis. Paragonimiasis is thought to be endemic in south-western Côte d'Ivoire. Methods. Two cross-sectional surveys were carried out in the first half of 2009 in patients attending two tuberculosis centres of Abidjan. A third cross-sectional survey was conducted in May 2010 in children of two primary schools in Dabou, where crabs are frequently consumed. Patients with chronic cough provided three sputum samples plus one stool sample. Sputum samples were examined for tuberculosis with an auramine staining technique and for Paragonimus eggs using a concentration technique. Stool samples were subjected to the Ritchie technique. Schoolchildren provided a single stool sample, and samples were subjected to the Kato-Katz and an ether-concentration technique. A pre-tested questionnaire was administered to patients and schoolchildren to investigate food consumption habits. Additionally, between June 2009 and August 2010, shellfish were purchased from markets in Abidjan and Dabou and examined for metacercariae. Results: No human case of paragonimiasis was diagnosed. However, trematode infections were seen in 32 of the 272 shellfish examined (11.8%). Questionnaire results revealed that crab and pig meat is well cooked before consumption. Among the 278 patients with complete data records, 62 had tuberculosis, with a higher prevalence in males than females (28.8% vs. 13.9%, Χ2 = 8.79, p = 0.003). The prevalence of helminths and intestinal protozoa was 4.6% and 16.9%, respectively. In the school survey, among 166 children with complete data records, the prevalence of helminths and intestinal protozoa was 22.3% and 48.8%, respectively. Boys had significantly higher prevalences of helminths and intestinal protozoa than girls. Hookworm was the predominant helminth species and Entamoeba coli was the most common intestinal protozoon species (13.8%). Conclusions: Not a single case of Paragonimus was found in two high-risk groups of Côte d'Ivoire, most likely explained by food consumption habits. However, other helminth and intestinal protozoon infections were common. © 2011 Traoré et al; licensee BioMed Central Ltd. Source

Titi A.,University of Mentouri Constantine | Mekroud A.,University of Mentouri Constantine | Sedraoui S.,University of El-Tarf | Vignoles P.,UPRES EA No. 3174 | Rondelaud D.,UPRES EA No. 3174
Journal of Helminthology

Abstract Parasitological investigations on ruminal paramphistomosis were carried out in 2033 cattle over a 14-month period in three Algerian slaughterhouses to determine the prevalence and intensity of this disease. The prevalence of infection varied from different slaughterhouses (1.2% at El Khroub, 7.5% at Ferdjioua and 12.1% at Jijel). The worm burden was significantly higher in cattle from El Khroub than for those slaughtered in the other two sites (a mean of 984.1 parasites compared with 87.5 and 140.7 at Jijel and Ferdjioua, respectively). No significant correlation between prevalence, intensity of infection and age of cattle was noted. Overall, females were significantly more infected than males, whereas the sex of animals was independent of worm burdens recovered in slaughtered cattle. The climatic conditions of provinces in which the slaughterhouses were located (a more temperate climate for Jijel and semiarid conditions for the other two provinces) may partly explain variations noted in prevalence and intensity of infection. The present results will contribute to our understanding of the epidemiology of Paramphistomum daubneyi infections in north-eastern Algeria. © Cambridge University Press 2009. Source

Dar Y.,UPRES EA No. 3174 | Dar Y.,Tanta University | Djuikwo Teukeng F.F.,UPRES EA No. 3174 | Djuikwo Teukeng F.F.,University of Yaounde I | And 3 more authors.

Experimental infections of Egyptian Radix natalensis with French miracidia of Fasciola hepatica were carried out to determine if this snail might act as an intermediate host in the life cycle of this digenean in Egypt. Single exposures of R. natalensis to miracidia (2/snail) and two successive exposures (a total of 4 miracidia/ snail) were performed using lymnaeids measuring 1 to 6 mm in height. Live larval forms of F. hepatica were noted in single- and double-exposed snails. In double exposures, a significant increase of snail survival on day 28 post-exposure (at 24°C) and an decrease in prevalence were noted when the height of snails at exposure was increasing. Cercariae of F. hepatica were shed by these snails (90.7/snail) during a mean patent period of 24.3 days. All snails have released these cercariae during 2-13 waves of shedding. According to these results, R. natalensis can be considered a potential intermediate host of F. hepatica in Egypt. Source

Dar Y.,Tanta University | Vignoles P.,UPRES EA No. 3174 | Dreyfuss G.,UPRES EA No. 3174 | Rondelaud D.,UPRES EA No. 3174
Journal of Helminthology

Experimental infections of Egyptian Radix natalensis with a French isolate of Fasciola hepatica (each snail was subjected twice to a bimiracidial exposure) were carried out to determine how many sporocysts grew in these snails and to study the developmental patterns of redial generations. Single-sporocyst infections were found in 69.3% (34/49) of infected snails, with equivalent numbers of normal and abnormal patterns. Snails with two- and three-sporocyst infections were 24.4% and 6.1%, respectively. In single- and two-sporocyst infections at days 42 and 56 post-exposure, the total redial burden was significantly higher in snails with a normal redial development. In two- and three-sporocyst infections, the overall maturity of rediae was delayed at days 42 and 56. The high frequency of abnormal patterns in R. natalensis (53.1% of all infected snails showed degeneration of a first mother redia) might be due to incomplete adaptation between the snail population and the parasite. The delayed redial maturity in two- and three-sporocyst infections can mainly be explained by the volume of the snail body, which would be insufficient to allow the simultaneous differentiation of most rediae over time. Copyright © Cambridge University Press 2010. Source

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