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G Vassiliades

Publications and source records attributed to G Vassiliades.

At least 19 recordsLinked to original sources
PubMed1992

Preliminary observations on helminth parasite populations of the dromedary in northern Mali.

An abattoir survey on gastrointestinal parasites of the dromedary (Camelus dromedarius) was carried out in March/April 1987 in northern Mali. Parasitological examination of the digestive tract contents of 11 dromedaries revealed that Haemonchus longistipes was the predominant parasite with a prevalence as high as 85.7%. The genera Impalaia, Trichostrongylus, Cooperia, and Oesophagostomum were also recovered, but with a lower level of infection and frequency. The larval stage of the canine cestode Echinococcus granulosus was recorded in a single instance.

Abattoirs↗
PubMed1991

[Epidemiology of intestinal schistosomiasis with Schistosoma mansoni in Richard-Toll (Delta of the Senegal River). Malacological study].

A recent outbreak of intestinal schistosomiasis (1989) has been reported in Richard-Toll (Delta of Senegal River) with a global prevalence of 43%. A malacological survey has been carried in order to study, the density of Biomphalaria pfeifferi the intermediate hosts, their distribution and rate of infection, and to identify the transmission sites. Ten districts have been selected. The snails have been collected in the different water points of these localities which are the river, the Taouey marigot, the Taouey channel and the irrigation channels and drains of the CSS (Senegal Sugar Company). A total of 1,210 Biomphalaria have been collected in 45 sites with a variable density of 2 to 150 snails. The overall rate of infestation of snails is 44% but varies according to the districts (9 to 64%). The transmission is acting in all the districts mainly in the Taouey channel (28% of infested snails) the Taouey marigot (38% of infested snails) and particularly in the channels of CSS (47% of infested snails). The situation is alarming and requires urgent action be undertaken to decrease the prevalence and reduce the transmission.

Animals↗
PubMed1987

[Morphology of the teguments of Schistosoma haematobium; comparison with S. curassoni, S. bovis and S. intercalatum].

Study by SEM of the anterior dorsal teguments of male Schistosoma haematobium from infected rodents. Only paired males, at least hundred days post infection, display a typical morphology. Differentiation from other closely related species obtained experimentally from rodents is possible: bovis: no spines on the tubercles; haematobium: tubercles 10 to 15 microns wide with closely packed spines; curassoni: tubercles over 15 microns wide, with large, closely packed spines; intercalatum: tubercles under 10 microns wide, with scattered spines. It is suggested that the three haematobium genotypes A, B and D are slightly different: A: pointed spines, numerous small additional spines between the tubercles; B: pointed spines, no small additional spines between the tubercles; D: blunt spines. Moreover, the lengths of the prepatent periods in the molluscs of the three S. haematobium genotypes are possibly different: A 72-86 days, B 38-46 days, D 55-58 days. The differentiation of A, B and D is supported by limited data and conclusions on this particular aspect are presented only as a working hypothesis.

Animals↗
PubMed1985

[Survey on Schistosomes of man and livestock in Senegal using specific identification given by chetotaxy of cercaria. I. New arguments for the validation of S. curassoni Brumpt, 1931, parasite of man and domestic Bovidae].

Study of Senegal cercariae emitted by naturally infected snails or by snails experimentally infected using eggs from human urine or from sheep liver, and study of the corresponding eggs. The relative position of the dorsal sensillae of cercariae is described by an "AD index" and the ratio length/width of eggs by an "L/l index." At the present time, we have not finished the epidemiological studies, certain experiments are imperfect and the isoenzyme analysis of the corresponding adults is incomplete. Nevertheless information given by the indices AD and L/l agree and lead us to admit the existence of a Schistosome different to mattheei, haematobium and bovis and which, following Brumpt and Gretillat we refer to as Schistosoma curassoni. If one relies on the indices, the study indicates that: a) S. mattheei has not been found in Senegal, b) S. bovis is quite rare, c) S. haematobium apparently exists in pure infections in Casamance and in mixed infections with S. curassoni in man in the north and in the east, d) S. curassoni is apparently the dominant species in domestic ruminants and in man in the north and in the east, e) Bulinus umbilicatus is the principal vector of S. curassoni and S. haematobium.

Animals↗
PubMed1983

[Argyrophilic structures of the larval forms of 2 strains of Paramphistomum microbothrium: 1 a parasite of Isidora guernei and Ovis aries, the other a parasite of Isidora truncata and Bos taurus].

The life cycle of a Paramphistome from North Senegal is completed starting from cercariae shed by naturally infected Isidora guernei: a sheep and then uninfected Isidora guernei were successively infected experimentally. Adults obtained were identifiable as P. phillerouxi or as P. microbothrium. Species determination cannot be made on the basis of argentophilic structures in the miracidium. Morphology of sporocysts and rediae differs from that observed in P. phillerouxi but is undistinguishable from that described in P. microbothrium. Cercarial chaetotaxy differs from that of P. phillerouxi. Mollusc host: Isidora guernei belongs to the same genus as Isidora truncata and I. alluaudi, reported hosts to P. microbothrium. Therefore the material is provisionally identified as P. microbothrium. To confirm this, a strain of P. microbothrium from naturally infected Bos taurus in Egypt was studied. Miracidia were used to experimentally infect Isidora truncata; cercariae obtained were identical to those previously described for this species from I. truncata and I. alluaudi. Cercarial chaetotaxy was not significantly different from that of material from North Senegal. They represent therefore two strains of Paramphistomum microbothrium.

Animals↗
PubMed1981

[Superficial argentophilic structures of miracidium and cercaria of Paramphistomum phillerouxi Dinnik, 1961 (Trematoda, Paramphistomidae) (author's transl)].

Superficial argentophilic structures of the miracidium and cercaria of Paramphistomum phillerouxi Dinnik, 1961, are descrifed in detail. Concerning the miracidium they are similar to those of the miracidia of some species belonging to the genus. On the other hand the chaetotaxy of the cercaria is different from that of the cercaria of P. togolense (Alberet et coll., 1978) and therefore this appears to constitute a good criterium for the taxonomy of this group.

Animals↗