Ecologie des Leishmanioses dans le sud de la France

Abstract

Résumé.Poursuivant l'analyse systémique du foyer leishmanien des Cévennes méridionales, les auteurs exposent le résultat d'une étude des diverses formes, spontanées et provoquées, de la maladie canine ; cette étude basée sur une expérimentation au long cours et sur les données d'enquêtes, prend en compte simultanément, l'évolution clinique, parasitologique et immuno logique. Les deux types nosologiques classiques, patent et latent, sont confirmés. Le type latent est lui-même composé de formes précliniques, les plus fréquentes (environ 90 %), et de formes résolutives (environ 10 %). L'importance épidémiologique d'une telle distinction est soulignée. Ainsi, les états prépatents, souvent fort longs, peuvent permettre au parasite de se maintenir, plusieurs années durant, sans faire appel à la transmission vectorielle. En fait, l'établissement des fréquences et des durées de ces diverses formes constituent autant d'indices indispensa bles à l'amélioration des modèles théoriques, actuellement proposés. Summary.Ecology of leishmaniasis in the south of France. 10. Developmental stages and clinical characterization of canine leishmaniasis in relation to epidemiology.In an analytical study of a focus of leishmaniasis in Southern France (Cévennes), a clini cal, parasitological and immunological comparison was made of dogs with natural and expeAccepté le 30 mars 1979.Article available at http://www.parasite-journal.org or https://doi.org/10.1051/parasite/1979543277 278 G. LANOTTE ET COLLABORATEURS rimental infections of leishmaniasis. Observations were made in longterm laboratory expe riments and on dogs found infected in field surveys. Two main clinical forms, patent and latent, were apparent. The latent form could be further subdivided into two types namely preclinical (the commonor: about 90 %) and resolving (about 10 %). The epidemiological significance of these distinctions is emphasized. Prepatent states, often lasting for very long periods, can result on the maintenance of the parasites for several years without the need for transmission by the vector. The prevalence and duration of the different forms of disease in dogs are thought to be of great importance in the epidemiology of leishmaniasis in foci in which canids are reservoir hosts.

Distribution and relative density of three sandfly(Diptera : Phlebotominae)species in southern Switzerland

“…It now seems that drain holes represent optimal biological niches for this species, so it is possible that S. minuta may also be found in regions with less ideal climatic conditions and be protected in a biological niche which provides a very steady temperature and humidity. In addition such conditions are also favoured by the lizard Lacerta muralis (Laurenti), which is the main host of S. minuta (Rioux et al 1969). The apparent densities of the three species in southern Switzerland are approximately equivalent to those in Italy: S. minuta was caught in the greatest number of all sandfly species in Italy (Biocca et al 1977) and was similarly found in minor Mal cantone and western Mendrisioto at a high density.…”

“…All of the three species caught in the present study are within the geogra phical ranges previously described; P. mascittii has been previously recorded from southern Italy, southern Sardinia and northern France (Biocca et al 1977;Larrousse 1923, Langeron and Nitzulescu 1931, Callot 1950, P. perniciosus from northern Italy and northern France (Biocca et al 1977;Foley 1923, 1924, Lan geron and Nitzulescu 1932, Le Gac 1936, Colas-Belcour and Romana 1939, Ristorcelli 1939, Lavier and Ristorcelli 1940 and S. minuta from northern Italy and coastal mediterranean France (Biocca et al 1977;Rioux et al 1969). The present results show that the distribution of S. minuta can be continental, and present the northern-most European record of this species.…”

“…V ertical d istr ib u tio n The upper altitude limit for P. perniciosus in Ticino was 573 m, approximately the same as in France (eastern Pyrenees, 640 m; Epinouse mountains, 440 m; Cevennes mountains, 600 m) (Croset 1969, Rioux et al 1969, but considerably lower than in Spain (1,750 m) (Ubeda-Ontiveros 1978) and Italy (1,087 m) (Sarca 1949, Corradetti 1962, Biocca et al 1977. The vegetation in Ticino is already alpine at 573 m and is unsuitable for sandflies, compared to more favourable conditions at higher altitudes further south in Italy and Spain.…”

“…Conversely, Rioux et al (1969) caught many more specimens when light traps were used in conjunction with sticky papers, within the biological niche itself. This supports the conclusion that S. minuta is more dependent upon a well-defined microclimate which it is unwilling to leave.…”

The distance of attraction of CDC light traps to Phlebotomine sandflies

“…The comparatively high total catch in experiment 2 was probably due partly to the temperature, which was higher than during the other two experiments, but mostly to the time of experiment 2 which was the only one of the three done wholly during the peak period of activity of P. ariasi (21.00-24.00 hrs ; Rioux et al, 1969).…”