| fasciola hepatica: epidemiological surveillance of natural watercress beds in central france. | a total of 59 natural watercress beds in the limousin region (central france) was surveyed over a 15-year period (1990-2004) to detect the contamination of watercress by the metacercariae of fasciola hepatica and to determine the presence of larval forms in the two species of lymnaeids which live in these waterholes in june and july. the number of beds contaminated with f. hepatica metacercariae varied over the years, and the burden of the larvae on plants was low: a mean of 2.6-6.3 per bed. the ... | 2005 | 15682341 |