Showing papers in "Parasite in 2002"

An outbreak of cutaneous leishmaniasis among soldiers in Belém, Pará State, Brazil, caused by Leishmania (Viannia) lindenbergi n. sp. - A new leishmanial parasite of man in the Amazon region

Abstract: Eight cases of cutaneous leishmaniasis are recorded among soldiers of the Brazilian Forest Infantry stationed in Belem, State of Para, north of Brazil. The infections, all acquired during manoeuvres in nearby degraded primary forest, are attributed to a new member of the subgenus Viannia, Leishmania (V.) lindenbergi n, sp. A further infection by this parasite was encountered in a woman, who lived very close to the same piece of forest. The new parasite has been characterised and differentiated from other known species of the subgenus Viannia following the combined use of enzyme electrophoresis and monoclonal antibodies techniques. The eco-epidemiology of L. (V.) lindenbergi is discussed: by far the most abundant anthropophilic sandfly in the type locality was identified as Lutzomyia (Nyssomyia) antunesi (Coutinho), and this remains high on the list of possible vectors.

Identification of trypanosomes in wild animals from Southern Cameroon using the polymerase chain reaction (PCR)

Abstract: One possible explanation of the maintenance of many historical foci of sleeping sickness in Central Africa could be the existence of a wild animal reservoir. In this study, PCR was used to detect the different trypanosome species present in wild animal captured by hunters in the southern forest belt of Cameroon (Bipindi). Trypanosomes were also detected by a parasitological method (Quantitative buffy coat: QBC). Parasite could not be isolated in culture medium (Kit for in vitro isolation: KIVI). Specific primers of T. brucei s.l., T. congolense forest type, T. congolense savannah type, T. vivax, T. simiae and T. b. gambiense group 1 were used to identify parasites in the blood of 164 animals belonging to 24 different species including ungulates, rodents, pangolins, carnivores, reptiles and primates. Of the 24 studied species, eight were carrying T. b. gambiense group 1. Those parasites pathogenic to man were found in monkeys (Cercocebus torquatus and Cercopithecus nictitans), in ungulates (Cephalophus dorsalis and C. monticola), in carnivores (Nandinia binotata and Genetta servalina) and in rodents (Cricetomys gambianus and Atherurus africanus). 13 species (54%) were carrying T. brucei s.l. identified as non-gambiense group 1.

Alternative treatment for Anacanthorus penilabiatus (Monogenea: Dactylogyridae) infection in cultivated pacu, Piaractus mesopotamicus (Osteichthyes: Characidae) in Brazil and its haematological effects.

Abstract: Ce travail a etudie l'effet de 0, 1 000, 1 500 et 2000 mg d'ail en poudre par kg de ration seche sur Piaractus mesopotamicus (Osteichthyes: Characidae), pesant 73,6 ± 39,4 g et mesurant 15,0 ± 2,7 cm, alimente pendant une periode de 15, 30 et 45 jours. Apres 15 jours d'alimentation avec 1 000 et 2000 mg d'ail, une diminution significative du nombre d'Anacanthorus penilabiatus (Monogenea: Dactylogyridae) sur les branchies a ete observee. L'addition de l'extrait d'ail dans la ration alimentaire a provoque une augmentation significative du nombre d'erythrocytes et de thrombocytes dans le sang du poisson. Toutefois, une diminution des lymphocytes a ete aussi observee. Apres 45 jours de traitement, le poisson alimente avec ail a montre une augmentation significative des taux d'erythrocytes, de leucocytes, de thrombocytes et d'hemoglobine.

Hepatozoon kisrae n. sp. infecting the lizard Agama stellio is transmitted by the tick Hyalomma cf. aegyptium.

Abstract: Hepatozoon kisrae n. sp. a ete decouvert chez Agama stellio dans une localite du sud-est de la Samarie (Palestine). Ces Lezards sont egalemant les hotes de Hyalomma cf. aegyptium. Il est demontre que cet lxodide est le vecteur de l'Hemogregarine. Le cycle ne s'effectue que dans une zone precise : les Tiques d'une region voisine sont indemnes. Les micro et macromerontes se trouvent essentiellement dans les poumons, alors que les kystes (la plupart contenant deux cystozoites) siegent dans le foie. Les gametocytes intraerythrocytaires murs, de forme trapue, sont encapsules. Le developpement depuis l'oocyste jusqu'au sporocyste, qui a lieu dans l'hemocele de la Tique, a ete etudie en microscopie electronique. Les Lezards s'infectent par ingestion, soit de Tiques infectees de sporocystes, soit de visceres de Lezards infectes. Les Tiques s'infectent par repas sur Lezards infectes; la sporogonie est achevee 40 jours apres la fixation de la nymphe, lorque le stade adulte est atteint.

The effect of substrate on survival and development of two species of desert fleas (Siphonaptera: Pulicidae).

Abstract: Fleas Xenopsylla conformis mycerini and Xenopsylla ramesis replace each other on the same rodent host (Meriones crassus) in two habitats that differ in substrate texture (sand and loess-like sediments, respectively). We hypothesized that the substrate is an important factor determining flea distribution and studied survival of larvae, pupae and newly emerged adults as well as the rate of pre-imaginal development of these flea species in sand and loess rearing medium (= substrate). Texture of rearing medium did not affect survival and development rate of eggs in either X. c. mycerini or X. ramesis. Larval survival and the rate of development were both affected by the factor of substrate. Survival of X. c. mycerini larvae was significantly higher in sand than in loess substrate, whereas survival of X. ramesis larvae did not differ in different substrates. Larvae of both species developed faster in sand substrate than in loess substrate. Maximal survival time of X. c. mycerini larvae that died before pupation did not depend on substrate, whereas X. ramesis larvae survived significantly longer in loess than in sand substrate. Most pupae of both species survived successfully on both substrates, but the duration of pupal stages in sand substrate was longer than that in loess substrate in both species. Newly emerged adults of both species survived similar time in both sand and loess substrate. Irrespective of substrate, adult X. c. mycerini survived for a shorter time than did adult X. ramesis. No between-sex within-species differences in survival time of newly emerged adults in sand versus loess substrate were found in X. c. mycerini. Survival time of males and females of X. ramesis differed in sand substrate but not in loess substrate.

Insecticide mixtures for mosquito net impregnation against malaria vectors.

Abstract: Insecticides belonging to the pyrethroid family are the only compounds currently available for the treatment of mosquito nets. Unfortunately, some malaria vector species have developed resistance to pyrethroids and the lack of alternative chemical categories is a great concern. One strategy for resistance management would be to treat mosquito nets with a mixture associating two insecticides having different modes of action. This study presents the results obtained with insecticide mixtures containing several proportions of bifenthrin (a pyrethroid insecticide) and carbosulfan (a carbamate insecticide). The mixtures were sprayed on mosquito net samples and their efficacy were tested against a susceptible strain of Anopheles gambiae, the major malaria vector in Africa. A significant synergism was observed with a mixture containing 25 mg/m2 of bifenthrin (half the recommended dosage for treated nets) and 6.25 mg/m2 of carbosulfan (about 2% of the recommended dosage). The observed mortality was significantly more than expected in the absence of any interaction (80% vs 41%) and the knock-down effect was maintained, providing an effective barrier against susceptible mosquitoes.

Intestinal parasitoses among Wayampi Indians from French Guiana

Abstract: Intestinal parasitism and its epidemiological characteristics were studied in an isolated Amerindian population from Upper Oyapock (French Guiana) that has retained its traditional social and cultural specificities. This population consisted of 138 Wayampi Indians, 68 adults and 70 children (below the age of 15 years), with a sex ratio (M/F) of 0.86, spread over the four villages of the community of Trois Sauts, corresponding to more than two thirds of the population recorded as inhabiting the sector in the last census (375 inhabitants). Fecal examination combined the direct examination of fresh feces with the quantitative techniques of Kato-Katz method, Baermann and MIF staining. Overall, 92% of the subjects were found to have intestinal parasites, 85% if only direct examination of fresh stools was taken into account. Fourteen species of human parasite were identified: seven protozoa and seven helminths. We observed in particular 1) a high frequency of hookworm infection due to Necator americanus. Over 50% of subjects were affected, with a range of 25% to 75% according to the village, but with only moderate parasite loads; 2) a high level of parasitism by E. histolytica/E. dispar (17%), Stongyloides stercoralis (16%) and Hymenolepis nana (18%); 3) a lower level of parasitism by Ascaris lumbricoides and very low levels (almost absent) of Trichiuris trichiura; 4) the absence of Schistosoma and fluke eggs. With the exception of H. nana, which was more frequent in children than in adults, there was no significant difference in the level of parasitism according to sex and age. Although the Wayampi of French Guiana are French citizens and consequently have quite high incomes and ready access to clinics and medicines, intestinal parasites are far from under control in this population. A lack of fecal hygiene and the habit of walking barefoot are widespread in the unchanging Amazonian environment and contribute to this phenomenon.

Echinococcus granulosus down regulates the hepatic expression of inflammatory cytokines IL-6 and TNF alpha in BALB/c mice.

Abstract: Hydatid disease is caused by the metacestode of Echinococcus granulosus. Different experimental models have been used to understand hydatid disease. In current studies BALB/c mice were used to evaluate the hepatic response of IL-6 and TNF alpha triggered by Echinococcus granulosus. BALB/c mice were intraperitoneally infected with protoscoleces from E. granulosus; hydatid cysts appeared on the liver eight weeks after inoculation. The RNA extracted from hepatic sections was used for RT-PCR amplification with primers for IL-6, TNF alpha, IL-10, TGF beta and G3PDH. In situ cytokine expression was assessed by FISH. Complete parasite cysts on the liver surface were observed 16 weeks after infection; controls were negative. The expression of IL-6 and TNF alpha was normal at baseline and declined progressively eight weeks after infection; in some animals such expression was abrogated 16 weeks after infection. On the other hand IL-10 and TGF beta were increased progressively. Controls expressed the cytokines normally. Present results suggest that E. granulosus induces a local immunosupression probably mediated by IL-10 and TGF beta; therefore it seems possible that such a mechanism would assist the parasite in escaping the harmful host cell-mediated response.

Diversification of Cercopithifilaria species (Nematoda: Filarioidea) in Japanese wild ruminants with description of two new species.

Abstract: Twelve of the 17 Cervus nippon nippon deer from Kyushu Island, Japan, that we examined were infected with one or two Cercopithifilaria species. C. longa n. sp. adults were in the subcutaneous tissues of limbs and the abdomen, and C. crassa n. sp. adults were in the skin, mainly in the anterior part of the back ; the distribution of the dermal microfilariae generally matched that of the adult worms. The two new species were assigned to the group of primitive Cercopithifilaria species that parasitize ruminants (bovids and cervids), but the new species could readily be distinguished from others morphologically. C. longa was more primitive and resembled C. bulboidea, one of the five species from the serow Capricornis crispus , a Japanese member of the Caprinae, and species from Bovidae in Africa. C. crassa had a thick body and large spicules like C. rugosicauda from Capreolus capreolus in Europe, the only previously known Cercopithifilaria species from cervids, but it also had one or two hypertrophied pairs of caudal papillae, an unusual character found so far only in Japanese parasites. Among the 12 species known from ruminants, four are African, one is European and more highly evolved, and seven are Japanese, with some being primitive and some more evolved. The great diversity of Cercopithifilaria species in the two wild ruminants that live in Japan seems to have resulted from local speciation, which occurred during the Pleistocene, from a primitive form of the C. longa type derived from Eurasiatic ancestors, which has disappeared or, more probably, not yet been discovered.

Monitoring the drug-sensitivity of Plasmodium falciparum in coastal towns in Madagascar by use of in vitro chemosensitivity and mutation detection tests.

Abstract: La dissemination des souches de Plasmodium falciparum mutantes et resistantes contribue a la diffusion de la resistance aux antipaludiques. Les populations des zones portuaires sont particulierement exposees aux isolats de Plasmodium introduits associes a des cas de paludisme d'importation. Le traitement par la chloroquine aussi bien que par l'association sulfadoxine/pyrimethamine demeure une methode efficace pour la prise en charge des acces palustres simples a Madagascar. Dans le cadre du programme de surveillance du paludisme, des approches in vitro etaient utilisees pour evaluer la sensibilite des isolats de P. falciparum dans deux villes cotieres et portuaires malgaches : Mahajanga sur la cote Ouest et Toamasina sur la cote Est. Les isolats testes dans ces deux sites etaient tous sensibles a l'amodiaquine, a la quinine, a la pyrimethamine et au cycloguanil. A Mahajanga, les isolats ont ete sensibles a la chloroquine (n = 25; moyenne CI50 = 22,6 nM, intervalle de confiance 95 %: 16,8-28,7 nM), alors que trois isolats de Toamasina etaient de phenotype chloroquinoresistant (n = 18; moyenne CI50 = 66,3 nM; intervalle de confiance 95 %: 42,6-90 nM). La frequence des mutations Pfcrt Thr-76 et de dhfr Asn-108 etait estimee par PCR/RFLP. Les 43 isolats de P. falciparum analyses etaient tous de genotype sauvage (Pfcrt Lys-76 et dhfr Ser-108), classiquement associe a un phenotype sensible. Le phenotypage et le genotypage demontrent que la prevalence de souches de P falciparum resistantes a la chloroquine ou a la pyrimethamine est encore tres faible a Madagascar. Il s'avere ainsi que l'approche basee sur le test in vitro et le genotypage des marqueurs de resistance seraient utiles i) pour surveiller l'emergence des plasmodies resistantes aux antipaludiques majeurs a Madagascar, et ii) notamment pour pallier le manque d'equipes medicales competentes et experimentees pour la conduite des etudes in vivo. Le risque associe aux cas importes de paludisme est discute.

Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France.

Abstract: Four freshwater pulmonate species (Lymnaea ovata, L. stagnalis, Physa acuta, Planorbis leucostoma) were living in several watercress beds known for their relationships with human cases of fasciolosis, whereas L. truncatula was never found. The aims of these studies were to determine the prevalence of natural infections with Fasciola hepatica in snails and to verify if these species might ensure the full larval development of this trematode (with cercarial shedding) when they were experimentally subjected to F. hepatica only, or to co-infections with an other trematode species. Investigations were so carried out in six snail populations living in watercress beds (including three for P. acuta) and in four others originating from three brooks or a pond (as controls). Snails naturally infected with F. hepatica were found in two watercress beds inhabited by L. ovata (prevalence of infection: 1.4%) and P. leucostoma (0.1%), respectively. The L. ovata from the watercress bed could be infected at a higher size than those from the control population and the prevalence of this infection was greater in the bed population. Similar findings were noted for L. stagnalis. Despite single or dual infections, the results obtained with the four populations of P. acuta were unsuccessful. In contrast, the co-infections of young P. leucostoma with Paramphistomum daubneyi and F. hepatica resulted in the shedding of some F. hepatica cercariae. According to the authors, the occurrence of fasciolosis in these watercress beds would be the consequence of frequent natural encounters between parasite and snails (L. ovata, L. stagnalis), or of co-infections with P. daubneyi and F. hepatica (P. leucostoma). In watercress beds only colonized by P. acuta, a lymnaeid species would have ensured the larval development of F. hepatica but it would have been eliminated by P. acuta, as this last species was known to be invasive and could colonize open drainage ditches on siliceous soil.

Description of Paranoplocephala etholeni n. sp. (Cestoda: Anoplocephalidae) in the meadow vole Microtus pennsylvanicus, with a synopsis of Paranoplocephala s. l. in holarctic rodents.

Abstract: Nous decrivons Paranoplocephala etholeni n. sp., parasite du Campagnol des Prairies Microtus pennsylvanicus eh Alaska et Wisconsin. Paranoplocephala etholeni est morphologiquement le plus proche de l'espece nearctique Paranoplocephala ondatrae (Rausch, 1948). Les donnees disponibles suggerent que P etholeni est une espece dont l'hote est specifique et localement rare, mais neanmoins avec une aire de repartition large et sporadique en Amerique du Nord. La decouverte de cestodes du type P. ondatrae dans des especes de campagnols Microtus spp. suggerent que cette espece peu connue est en fait une espece parasite des campagnols, plutot que du rat musque (decrit comme hote type). Un synopsis sous forme de tableau de toutes les especes de Paranoplocephala s. l. de la region holarctique avec leurs principales caracteristiques morphologiques est donne.

La taeniose/ cysticercose à Taenia solium dans la Menoua (Ouest-Cameroun)

Abstract: La presente etude a ete conduite d'aout 1999 a avril 2000 et avait pour objectif de determiner la prevalence de la taeniose due a Taenia solium dans Bafou et Bamendou, deux groupements villageois de la Menoua (Ouest-Cameroun). Quatre (0,13 %) sur 3 109 echantillons de matieres fecales humaines ont ete trouves positifs pour des oeufs de Taenia spp. par la technique de la flottaison. Trois des quatre vers expulses etaient des T. solium et un etait T. saginata . Deux cas de cysticercose etaient presents dans une des familles ou vivait un porteur de T. solium .En plus, des enquetes coprologique et serologique pour la taeniose et la cysticercose a T. solium ont ete faites chez un groupe a risque constitue de bouchers et/ou langueyeurs (n = 137). Les resultats ont ete compares a ceux d'un groupe temoin (n = 198). Aucun porteur de Taenia n'a ete detecte par l'examen microscopique. Les prevalences de la cysticercose dans les deux groupes ont ete respectivement 3,6 et 4,5 %.

Activity of natural and synthetic naphthoquinones against Toxoplasma gondii, in vitro and in murine models of infection.

Abstract: L'effet de 14 naphthoquinones naturelles et synthetiques a ete evalue sur la multiplication de Toxoplosma gondii. Les etudes in vitro ont ete effectuees avec des cultures de fibroblastes 2C4 infectes avec la souche RH. Un ELISA a ete utilise pour mesurer la croissance du parasite. Pour les etudes in vivo, les souris ont ete infectees avec des tachyzoites de la souche RH ou des kystes de la souche EGS de T gondii. Les essais in vitro avec sept naphthoquinones ont demontre une inhibition importante du developpement intracellulaire de T gondii aux concentrations de 1 et 5 μg/ml. Seulement trois composes ont demontre une activite protectrice in vivo: 2-hydroxy-3'-(3'-pentenyl)-1,4-naphthoquinone (PHNQ4), 2-hydroxy-3-(1'-vinylphenyl)-1,4-naphthoquinone (PHNQ5) et 2-hydroxy-3-(1'-propen-3'-phenyl)-1,4-naphthoquinone (PHNQ6). Dans le groupe des animaux infectes avec la souche EGS et traites avec PHNQ4 (50 mg/kg/jour per os), une augmentation de sept jours de la survie des animaux a ete observee. Le traitement avec 100 mg/kg/jour per os ou 50 mg/kg/jour i.p. de PHNQS a provoque une augmentation de la survie de cinq et 16 jours respectivement. Le traitement avec 50 mg/kg/jour per os ou 50 mg/kg/jour i.p. de PHNQ6 a entraine une augmentation de la survie de quatre et de plus de 30 jours apres le traitement, respectivement. Ces resultats montrent donc que les naphthoquinones peuvent etre des molecules d'avenir pour le traitement de la toxoplasmose.

PCR-RFLP analysis of Giardia intestinalis using a Giardia-specific gene, GLORF-C4.

Abstract: Un clone d'ADN complementaire codant pour le gene GLORF-C4 qui etait considere comme specifique des souches de l'assemblage B a ete isole de la souche WB (de l'assemblage A) de Giardia intestinalis. Ce gene GLORF-C4 a ete amplifie a partir de tous les groupes de G. intestinalis en utilisant des oligonucleotides specifiques du gene GLORF-C4 de la souche GS, prototype des souches de l'assemblage B, et utilise pour detecter la presence de cystes de G. intestinalis dans les matieres fecales de sujet excretant des cystes. l'analyse en RPLF de ces produits d'amplification a permis la classification des differents groupes de G. intestinalis en deux categories distinctes : celle de l'assemblage A et celle de l'assemblage B.

Effect of a single dose (600 mg) of albendazole on Loa loa microfilaraemia.

Abstract: The problem of Loa-encephalopathy, which may occur after ivermectin treatment of patients harbouring high Loa microfilarial loads, might be solved if one could find a treatment regimen bringing about a significant but progressive decrease in the Loa microfilaraemia. A trial was performed in Central Cameroon, whose aim was to follow up for 10 months, and to compare the changes in the Loa microfilarial loads in two groups of patients, one treated with a single dose (600 mg) of albendazole (Alben, SmithKline Beecham) given with fatty food, and the other treated with mebendazole (100 mg, twice a day, generic tablets) at a fasting state. The microfilarial loads remained stable in the mebendazole group, whereas a significant decrease in microfilaraemia was recorded in the albendazole group (initial median load: 230 microfilariae per 50 microliters; median load ten months after: 84 microfilariae per 50 microliters). This should encourage further trials to evaluate the effects and the safety of two- or three-day albendazole regimens in patients infected with Loa loa.

Première mention de Phlebotomus à Madagascar (Diptera: Psychodidae). Description de Phlebotomus (Anaphlebotomus) Fertei n. sp. et de Phlebotomus (Anaphlebotomus) Huberti N. sp.

Abstract: Deux nouvelles especes de phlebotomes sont decrites de Madagascar : Phlebotomus (Anaphlebotomus) fertei n. sp. a partir de trois mâles et Phlebotomus (Anaphlebotomus) huberti n. sp. a partir de deux femelles. Leur rattachement au sous-genre Anaphlebotomus repose chez le mâle sur la presence de quatre epines sur le style, l'absence de lobe basal sur le coxite, un paramere bilobe, la presence de soies antero-inferieures sur le mesanepisterne et, chez la femelle, proche des especes asiatiques du sous-genre, de l'ornementation du pharynx et du cibarium et de la presence de spermatheques annelees avec un conduit commun. Une importante difference de taille du second espace interne transcrit (ITS2) de l'ADN ribosomique nous a amenes a decrire le mâle et la femelle sous deux binomes differents. Ces deux especes sont les deux premieres du genre Phlebotomus observees a Madagascar. Elles portent a six le nombre de taxons du sous-genre Anaphlebotomus (si on en exclut P. fortunatarum) et s'ajoutent aux especes connues : P. rodhaini , P. rousettus , P. stantoni et P. colabaensis.

Rôle d'Anopheles melas Theobald (1903) Dans la transmission du paludisme dans la mangrove du Saloum (Sénégal)

Abstract: Des etudes entomologiques realisees en zone de mangrove dans des villages situes dans le delta du Saloum, de juin 1995 a janvier 1998, ont permis de mieux comprendre la contribution d'An. melas Theobald (1903) dans la transmission du paludisme cotier. Parmi les cinq villages prospectes, trois : Simal, Djilor et Marlothie sont en bordure du fleuve Saloum ; les deux autres : Djifere et Diakhanor sont situes entre l'ocean et le fleuve. Dans cette zone cotiere, An. melas vit en sympatrie avec An. arabiensis et les proportions de ces deux especes varient suivant la position des villages par rapport a la ligne de mangrove et en relation avec les saisons. Dans les trois villages situes en bordure du fleuve Saloum, An. arabiensis predomine. Dans les deux villages situes sur le littoral,, An. melas predomine. L'endophagie, l'endophilie et l'anthropophile sont tres nettes chez An. melas dans cette zone ou il predomine. La transmission palustre s'effectue de juillet a mars avec un maximum en debut de saison seche. En periode de sympatrie, An. arabiensis est responsable de la transmission et lorsqu'il est absent, ce role revient a An. melas . L'intensite de la transmission, bien que faible, est comparable dans les trois villages du delta a predominance An. arabiensis et dans les deux villages du littoral a predominance An. melas . An. melas etait tres anthropophile dans la zone du littoral mais s'infectait faiblement du fait d'une longevite tres reduite.

Transferrin coupled azanthraquinone enhances the killing effect on trypanosomes. The role of lysosomal mannosidase.

Abstract: Partially purified azanthraquinone (AQ) extract from Mitracarpus scaber was coupled to bovine transferrin (Tf) using azidophenyl glyoxal (APG). The AQ-APG-Tf conjugate was found to possess an enhanced in vitro trypanocidal activity against Trypanosoma congolense and T. brucei brucei. At low concentrations of 0.39-90 mg/ml, the conjugate diminished the growth of T. congolense and T. b. brucei dose dependently at the logarithmic phase. Both parasites were more sensitive to AQ-APG-Tf than to the free (AQ) extract. Growth inhibition on the parasites by the free extract was observed at 20-200 mg/ml. The total activity of the lysosomal enzyme a-mannosidase was reduced in the T. congolense cells treated with AQ-APG-Tf in a dose related pattern. However, the activity of the mannosidase in the T. b. brucei treated cells is less affected. The AQ-APG-Tf is more effective on a mannosidase than free AQ, eight and four fold for T. congolense and T. b. brucei respectively. The results are discussed as regards the potency of using transferrin as suitable drug carrier in the chemotherapy of Human sleeping sickness.

Eosinophil and mast cell expression in host skin during larval development of the human bot fly Dermatobia hominis.

Abstract: Les eosinophiles et les mastocytes du derme superficiel de rats Wistar (Ratlus norvegicus), infectes par des larves de Dermatobia hominis, ont ete quantifies et analyses Les eosinophiles dans la couche superficielle parasitee ont augmente de maniere marquee jusqu'au 10 e m e jour apres l'infection (dpi), puis decru jusqu'au 28 e m e jour qui correspond au moment ou la larve de troisieme stage emerge de l'hote, En ordre croissant, les comptages d'eosinophiles les plus eleves ont ete observes chez les rats apres 1, 4, 28, 20, 15 et 10 dpi, correspondant ou premier (1 et 4), troisieme (20 et 28) et deuxieme (10 et 15) stages. Les quantites d'eosinophiles ont ete significativement plus elevees que celles observees pour les animaux du groupe controle (a l'exception de 1 dpi). Les nombres de mastocytes ont ete plus eleves au debut de l'infestation (4 dpi), suivis par ceux du 20 e m e jour. En ordre croissant, les quantites de mastocytes ont ete plus elevees pour 10, 28, 15, 1, 20 et 4 dpi, bien que des differences significatives avec le groupe controle n'aient ete notees que pour 10 et 28 dpi. Les eosinophiles et mastocytes ont montre une correlation negative seulement chez les animaux ayant une larve du deuxieme stage (10 et 15 dpi). Des analyses comparatives ont ete egalement effectuees apres avoir divise la peau en quatre regions distinctes. Les resultats suggerent que l'expression des deux types de cellules, particulierement les eosinophiles, est une reponse importante de l'hote a l'infestation par D hominis.

Host age influence on the intensity of experimental Trichuris suis infection in pigs.

Abstract: L'impact de la resistance liee a l'âge dans la dynamique de la population et l'epidemiologie de Trichuris suis a ete etudie experimentalement chez le porc. Des porcs non porteurs d'helminthes et âges de cinq semaines a quatre ans ont ete inocules par T. suis afin d'en etudier la susceptibilite a l'infection. Les taux d'infestation par les vers adultes sont tres significativement plus bas chez les truies que chez les porcelets. La population de vers adultes est tres dispersee chez les truies et les porcs a l'engrais, ce qui n'est pas le cas chez les porcelets. La fecondite des vers est significativement plus faible chez les truies que chez les porcelets et porcs a l'engrais; chez ces derniers, les vers adultes sont egalement moins feconds que chez les porcelets. En conclusion, la preuve experimentale de l'influence de l'âge en matiere de resistance a l'infestation par T. suis est apportee pour la premiere fois.

Thelohanellus bicornei n. sp. Myxosporidie (Myxosporea, Bivalvulida) parasite des branchies de Labeo coubie Rüppel, 1832 (Osteichthyen, Cyprinidae) au Burkina Faso, Afrique de l'Ouest.

Abstract: Thelohanellus bicornei n. sp. (Myxosporea, Bivalvulida) parasite des branchies de Labeo coubie Ruppel, 1832 (Poisson, Cyprinidae) au Burkina Faso, Afrique de l'Ouest, se presente sous forme de kystes de 150 a 350 μm, souvent attenants, blanchâtres et arrondis. Les spores sont ovoides avec des surfaces valvaires lisses. Elles ont une extremite anterieure pourvue de deux "eperons" et une extremite posterieure arrondie. Elles mesurent de 13,5 ± 0,56 μm de long sur 8,43 ± 0,49 μm de large. Les eperons de taille egale ont entre 1 et 1,5 μm de long. Les spores possedent une capsule polaire piriforme de 7,24 ± 0,45 μm de long sur 3,75 ± 0,32 μm de large, contenant un filament polaire enroule sur 10 tours de spire.

Monogeneans from Pangasiidae (Siluriformes) in Southeast Asia: III. Five new species of Thaparocleidus Jain, 1952 (Ancylodiscoididae) from Pangasius bocourti, P. djambal and P. hypophthalmus.

Abstract: The examination of gill parasites from Pangasius bocourti Sauvage, 1880; P. djambal Bleeker, 1846; P. hypophthalmus (Sauvage, 1878) and P. gigas Chevey, 1930 (Siluriformes, Pangasiidae) revealed the presence of seven species of Monogenea among which five are considered new species. They all belong to Thaparocleidus Jain, 1952 (Ancylodiscoididae) as defined by Lim (1996) and Lim et al. (2001). P. bocourti: T. combesi n. sp., T. komarudini n. sp. and T. vietnamensis n. sp. P. djambal: T. caecus (Mizelle & Kritsky, 1969), T. combesi n. sp., T. euzeti n. sp., T. komarudini n. sp. and T. sadilii n. sp. P. hypophthalmus: T. caecus, T. siamensis (Lim, 1990) and T. vietnamensis n. sp. P. gigas: no Monogenea were found on this host species.

Onchocerciasis in West Africa after 2002: a challenge to take up.

Abstract: Prevu initialement pour une duree de 20 ans, le programme OMS de lutte contre l'onchocercose en Afrique de l'Ouest (OCP) aura finalement poursuivi ses activites pendant pres de trois decennies (lutte antivectorielle seule de 1975 a 1989, puis lutte antivectorielle et/ou therapeutique jusqu'en 2002). Bien que dans le perimetre d'OCP l'onchocercose ne soit plus un probleme de sante publique ni un obstacle au developpement socioeconomique, la lutte contre cette filariose n'en est pas terminee pour autant car l'OCP n'a jamais vise l'eradication, ni du parasite (Onchocerca volvulus), ni de son vecteur (Simulium damnosum s.l.). En 2003, les onze pays participants de l'OCP prendront la responsabilite des activites residuelles de surveillance et de controle de cette maladie. La mission est d'importance car une recrudescence de la transmission aboutirait a terme a la reapparition des signes cliniques de l'onchocercose, sinon de ses manifestations les plus graves. Pour des raisons epidemiologiques et operationnelles, et eu egard a la disparite des politiques et structures sanitaires nationales, les capacites des pays a prendre en charge les activites residuelles de surveillance et de lutte contre l'onchocercose sont tres inegales. Les interventions a mener sont en effet tres differentes d'un pays a l'autre et le processus d'integration des activites residuelles dans les systemes nationaux de sante ne s'opere pas au meme rythme. Cette inegalite des pays face aux defis a relever ne prejuge toutefois pas de la situation epidemiologique apres 2002 dont l'evolution dependra egalement de l'efficacite des dispositions prises auparavant par l'OCP puis, apres 2002, par le Bureau Regional pour l'Afrique de l'Organisation Mondiale de la Sante qui est en train de mettre en place une structure sous-regionale de surveillance pluripathologique.

Schistosoma mansoni: kinetics of glomerulonephritis in Mongolian gerbils and its correlation with intensity and duration of infection.

Abstract: Les lesions glomerulaires des patients atteints de schistosomiase ont ete souvent rapportees, cependant, il n'a pas ete developpe de modele animal permettant d'etudier les lesions de glomerulonephrites. Afin d'analyser les relations entre glomerulonephrite et infection a Schistosoma mansoni, des gerbilles, Meriones unguiculatus, ont ete infectees avec des quantites variables de cercaires et sacrifiees a des dates differentes apres cette infestation. 50 cercaires sont la quantite optimale pour provoquer une glomerulonephrite sans entrainer la mort de l'animal. Les gerbilles infectees montrent des lesions glomerulaires heterogenes avec une elevation de la creatinine serique. Il n'a pas ete observe de depots de complexes immuns au niveau des glomerules, ni en immunofluorescence, ni en microscopie electronique a transmission. Cependant, un infiltrat de cellules mononuclees dans et autour certains glomerules a ete observe. Une etude immunohistochimique, utilisant un anticorps monoclonal (HUSM-M.g.15) specifique de cellules T de gerbilles, a revele une infiltration de ces cellules. Cette decouverte suggere que les cellules T pourraient intervenir dans le developpement de la glomerulonephrite. Les gerbilles pourraient etre un bon modele afin de clarifier le role des cellules T dans le developpement des glomerulonephrites schistosomiennes.

The role of nitric oxide and lipid peroxidation in patients with Plasmodium vivax malaria.

Abstract: les auteurs ont etudie le role du metabolisme de l'oxyde nitrique et de la peroxydation de lipides chez des patients atteints de malaria a P. vivax. Les niveaux de nitrite et de nitrate ont ete analyses enutilisant un procede base sur la reaction de Griess et les niveaux de malondialdehyde index de la peroxydation de lipides ont ete determines par la reaction a l'acide thiobarbiturique. Les niveaux de nitrile/nitrate et de malondialdehyde des malades etaient plus eleves que ceux des temoins de facon statistiquement significative (p < 0,001). Cette etude a ete realisee pour determiner si le NO et la peroxydation de lipides s observent au cours du stade sanguin du cycle de P vivax. Il apparait que la peroxydation de lipides s'observe dans la malaria a P. vivax; les niveaux de l'oxyde nitrique etant associes a cette peroxydation.

Molecular characterisation of airport malaria: four cases in France during summer 1999.

Abstract: Four airport malaria cases have been observed in the vicinity of the Roissy-Charles-de-Gaulle International Airport, Paris, France. These cases were geographically very close to each other and clustered in a short period of time during the summer of 1999. The phenotype and genotype of the Plasmodium falciparum isolates obtained from these patients were determined in order to know whether a single mosquito could have infected more than one subject. The genomic characterisation of isolates was performed using the polymorphic markers merozoite surface protein 1 (Msp 1) and merozoite surface protein 2 (Msp 2) genes, the kappa and omega repeats domains of cg2 and the dihydrofolate reductase (DHFR) genotypes. Results showed identical genotypes for isolates 1, 2 and 4 whereas the genotype of isolate 3 differed at one locus. The molecular analysis was consistent with the hypothesis that all patients could have been bitten by the same mosquito and that patient 3, may have received a different clone and an additional species. In vitro susceptibility data did not confirm or rule out this hypothesis because isolates had the same profile of susceptibility to the tested drugs.

Is the Octomacridae the sister family of the Diplozoidae

Abstract: Diplozoidae and Octomacridae are usually considered as sister families. Essentially this is because they are the only polyopisthocotyleans parasitising primary freshwater teleosts. Because of the lack of phylogenetically informative morphological characters to explore the pattern of colonisation of the primary continental freshwater teleosts and in order to understand the appearance of the "natural parabiosis" of Diplozoidae, a molecular phylogeny was inferred by comparing newly obtained partial 28S and 18S rDNA gene sequences of Eudiplozoon nipponicum and Diplozoon homoion with other already available sequences. The phylogenetic analysis seems to show that Diplozoidae and Octomacridae are not sister groups. Thus, the colonisation of primary freshwater teleosts by these two families could be independent.

Les ailes de glossines, une carte d'identité de l'insecte?

Abstract: The size of tsetse flies is often associated with population dynamics and vectorial capacity parameters. Adult fly size is generally estimated from measurements of wing segments. To take measure of the wing, a semi-automatic software was developed by CIRAD-EMVT and IRD. It was used in wild populations of Glossina tachinoides Westwood and G. palpalis gambiensis Vanderplank (Diptera: Glossinidae) trapped near Bobo-Dioulasso, Burkina Faso. From an numeric picture of the wing, the software calculates the length of vein segments, the ratios between these lengths, the surface of the tsetse characteristic "hatchet cell", and the greyness on the wings. The data were interesting at the level of taxonomy. In addition, they help specify physiological characteristics of the studied populations.