The overwintering of eggs, intramolluscal stages and metacercariae of Fasciola hepatica under the temperatures of a Mediterranean area (Madrid, Spain)

• Published in: Veterinary parasitology Vol. 55; no. 1-2; pp. 143 - 148
• Main Authors: Luzón-Peña, M., Rojo-Vázquez, F.A., Gómez-Bautista, M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.1994
• Subjects: Animals; CICLO VITAL; CYCLE DE DEVELOPPEMENT; Embryo, Nonmammalian - physiology; FASCIOLA HEPATICA; Fasciola hepatica - growth & development; Fasciola hepatica - physiology; Fascioliasis - parasitology; Female; Gastropoda; HIBERNACION; HIBERNATION; LIFE CYCLE; Life cycles-Trematoda; MEDITERRANEAN ZONE; Oocytes - physiology; Seasons; Sheep; Snails - parasitology; Spain; TEMPERATURA; TEMPERATURE; ZONA MEDITERRANEA; ZONE MEDITERRANEENNE; Spain; Spain, Madrid; Fasciola hepatica; Life cycles-Trematoda
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/0304-4017(94)90065-5

The survival of embryonated and umembryonated eggs, of snails with mature or immature infection and of metacercariae over the winter of a Mediterranean area was analyzed. Embryonated eggs were more resistant than unembryonated eggs to cold weather, leaving a residual contamination which was responsible for earlier spring infection of the snail. Overwintering was similar in snail populations with both mature and immature infections although the lifespan was shorter in the former. Both snail populations survived in the mildest winter but not in the coldest. Only metacercariae from mid autumn were able to overwinter in an significant proportion (45%) but they were non-viable by mid spring. Our results suggest that in very cold winters no risk for grazing animals should be expected in spring.