Fasciola hepatica: The influence of the definitive host on the characteristics of infection in the snailLymnaea truncatula

Autor: G. Dreyfuss, D. Rondelaud
Rok vydání: 1995
Předmět:
Zdroj: Parasite. 2:275-280
ISSN: 1776-1042
1252-607X
DOI: 10.1051/parasite/1995023275
Popis: Summary: Investigations were carried out in Lymnaea truncatula to determine whether redial burden and shedding of F. hepatica cercariae vary when the same population of Lymnaea truncatula is exposed to miracidia that hatched from eggs collected in different naturally infected definitive hosts (cattle, sheep, and rabbits originating from the same region). Snails measuring 4 mm in height wete each exposed to two miracidia hatched from these eggs, and were then raised at 20 °C for 30 days. The prevalence of infected snails was 35 %, 66 %, and 86 % in the groups exposed to miracidia originating from rabbits, sheep, and cattle respectively. Cercariae were shed from snails of the three groups, however, shedding varied greatly depending on the origin of the miracidia. The total number of cercariae was significantly decreased in the group infected with miracidia from rabbits than in the others (54.5 per snail vs 1 57.8 and 21 6.4). The arcadian rhythm in the shedding of cercariae was also changed in the former group, with maximal shedding between 4 a.m. and 8 a.m. No significant difference was noted in the other characteristics of snail infection between the three groups. Histological examination of infected snails revea­ led that the total number of rediae was significantly decreased at day 30 in the snails infected from miracidia that originated from rabbits than in the other groups (a mean of 2 1 .3 vs 38.4 and 43.7). Degenerated, free rediae were most numerous in the for­ mer group than in the two others. The definitive host species may play a role in the development of Fasciola infection in the snail by limiting redial and cercarial burdens. From this study, trematode eggs collected in cattle or sheep are more efficient for transmission of the disease than those obtained from rabbits.
Databáze: OpenAIRE