RESUMEN
1200 adult Biomphalaria glabrata were submitted during 6 weeks to anhydrobiosis condition. Some snails were health, some were previously infected 3 days or 12 days ago with 8 ñ 2 miracidia of Schistosoma mansoni, others were shedding cercariae . The snails were put on soil or buried into hermetically closed, or ventilated, plastic boxes. There was no survival of snails kept in sealed boxes, or among positive snails, but 44% of control health snails and 40,6% of infected (for 3 or 12 days) snails in ventilated boxes were living at the term of the desiccation stage. Survival was better for "on soil" snails than for "buried" snails, but difference was shown between 3-days and 12-days infection. The surving desiccated B. glabrata had a lesser death rate and a lesser cercarial production than infected snails kept in water. An inferior production of male cercariae comparatively to female and to "mixed" cercariae was demonstrated by statistical analysis of the cercarial sheddings. In all positive snails, periodic variations of cercarial production was shown, whatever the sex of those cercariae. In addition many pauses of the sheddings were established by the authors
Asunto(s)
Animales , Biomphalaria/parasitología , Desecación , Schistosoma mansoni/fisiologíaRESUMEN
1200 adult Biomphalaria glabrata were submitted during 6 weeks to anhydrobiosis condition. Some snails were healthy, some were previously infected 3 days or 12 days ago with 8 +/- 2 miracidia of Schistosoma mansoni, others were shedding cercariae. The snails were put on soil or buried into hermetically closed, or ventilated, plastic boxes. There was no survival of snails kept in sealed boxes, or among positive snails, but 44% of control healthy snails and 40.6% of infected (for 3 or 12 days) snails in ventilated boxes were living at the term of the desiccation stage. Survival was better for "on soil" snails than for "buried" snails, but no difference was shown between 3-days and 12-days infection. The surviving desiccated B. glabrata had a lesser death rate and a lesser cercarial production than infected snails kept in water. An inferior production of male cercariae comparatively to female and to "mixed" cercariae was demonstrated by statistical analysis of the cercarial sheddings. In all positive snails, periodic variations of cercarial production was shown, whatever the sex of those cercariae. In addition many pauses of the sheddings were established by the authors.
Asunto(s)
Biomphalaria/fisiología , Desecación , Animales , Biomphalaria/parasitología , Schistosoma mansoni , Esquistosomiasis mansoni/parasitologíaRESUMEN
410 Biomphalaria glabrata (Caribbean strain of Guadeloupe) have been infected with one miracidium of Schistosoma mansoni, 110 snails, used as controls have been kept into water; the survival rate was 96.4% after 4 weeks and 25.4% produced cercariae. 300 snails were kept on wet soil, and submitted for 6 weeks to progressive desiccation. The survival rate was 23.4% but only 9 of them produced cercariae. Periodic variations of the production of male and female larvae have been shown by the weekly test of the cercariae productions. In previously desiccated snails, the production of male and female cercariae is similar while in controls the production of female larvae is more important. In experimental snails, the larval development seems to be stopped during anhydrobiosis. The production of cercariae is just delayed for the length of the dry keeping.
Asunto(s)
Biomphalaria/parasitología , Desecación , Schistosoma mansoni/crecimiento & desarrollo , Animales , Femenino , Masculino , Factores SexualesRESUMEN
In 54 patients (45 Africans and 9 West-Indians) we searched schistosomiasis and the presence of immunoglobulins E by different tests (total immunoglobulin E levels, measurement of specific IgE, human basophil degranulation test). In patients with an excretion of living eggs we observed 91.6% of positive responses for the II. B. D. T. and 100% for the specific IgE. In cases only identified by examination of rectal mucosa biopsy specimens showing apparently living eggs, we observed 75% and 87.5% of positive responses for the same tests. But in both categories of patients, the parasitological examination is the most important. Moreover the authors observed "false-positive" and "false negative" tests compared with the parasitological results and between the tests. It suggests that the best use of these is in case of very probable schistosomiasis without positive parasitological results.
Asunto(s)
Basófilos/inmunología , Inmunoglobulina E/análisis , Esquistosomiasis/diagnóstico , África/etnología , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Mucosa Intestinal/parasitología , Paris , Recto/parasitología , Esquistosomiasis Urinaria/diagnóstico , Esquistosomiasis mansoni/diagnóstico , Indias Occidentales/etnologíaRESUMEN
Immature and mature Biomphalaria glabrata are kept out of water at relative humidities varying from 0 to 100%. When snails are submitted to a saturated atmosphere, they show a slow weight loss and survival may be long. If relative humidity (RH) decreases, weight loss becomes important and survival is short. A reduced RH (0 to 65%) produces similar effects. During desiccation, fasting has no noticeable effect; survival depends essentially on weight loss.
Asunto(s)
Biomphalaria/fisiología , Peso Corporal , Privación de Agua , Animales , HumedadRESUMEN
Occasioning in Guadeloupe a high rate of morbidity, schistosomiasis is unequally spread in the field. The intermediate host, Biomphalaria glabrata, is wide-spread. But some biotopes only, most of them located on the coast belt of the montainous island, allow the parasite growth. Among them, the irrigation canals appear as the most dangerous source of contamination for human population.
Asunto(s)
Biomphalaria/parasitología , Vectores de Enfermedades , Schistosoma mansoni/crecimiento & desarrollo , Esquistosomiasis/transmisión , Animales , Clima , Ecología , Ambiente , Humanos , Indias OccidentalesRESUMEN
Examination of rats (Rattus norvegicus) trapped in Guadeloupe and naturally infected by Schistosoma mansoni reveals the massive presence of these parasites (adults and eggs) in the lungs.
Asunto(s)
Pulmón/parasitología , Ratas , Enfermedades de los Roedores/parasitología , Esquistosomiasis/veterinaria , Animales , Hígado/parasitología , Esquistosomiasis/parasitología , Indias OccidentalesRESUMEN
Examination of rats (Rattus norvegicus) in Guadeloupe (French West Indies) shows that their infection by Schistosoma mansoni is not restricted to any particular habitat.
Asunto(s)
Ratas , Enfermedades de los Roedores/epidemiología , Esquistosomiasis/veterinaria , Animales , Schistosoma mansoni , Esquistosomiasis/epidemiología , Indias OccidentalesRESUMEN
We compared the infestation of different strains of B. glabrata from Brasil (Recife). Guadeloupe, Martinique and Porto-Rico with 6 to 8 miracidia of S. mansoni (from Recife. We noted the four following points: 1. The planorbid snails from Martinique and Guadeloupe had a low resistance to infestation. 2. The guadeloupean snails showed the lesser rate of positivity and the lower medium amount of emitted cercaries but, in the four strains of snails, the level of the issued cercaries is quite the same. 3. many planorbid snails in the groups studied during more than 2 months, showed significant periodic variations in the emission of cercaries, We thought that those variations might be caused by the alternate maturations of sporocysts born from the same miracidium or from different miracidia. 4. Infestation by S. mansoni had a strong effect on fecondity of the snails but the laid eggs had a normal development.