Developmental differences in the uterus of Fasciola hepatica between livestock liver fluke populations from Bolivian highlands and European lowlands.

A morphometric study of the uterus area (UA) of Fasciola hepatica adults was carried out with the aid of a computer linked to a stereomicroscopic 3CCD colour video camera using image analysis software. The UA of adult liver flukes found in naturally infected sheep, cattle and pig from the endemic human fascioliasis zone of the northern Bolivian Altiplano highlands was compared with that of flukes found infecting sheep and cattle from Valencia, Spain and cattle from Corsica, France (collectively, European lowlands). Liver fluke UA was examined using an allometric model. A comparison of the allometry of the liver fluke UA in different host species from Bolivia revealed no significant differences. Similarly, no statistically significant differences were found between UA of Valencian and Corsican populations. However, the Bolivian sheep and cattle liver fluke populations proved to have a UA smaller than that of the European populations. These results indicate differences between the liver fluke population of highlands and lowlands, regarding UA. This paper discusses the possible relationship between the characteristic of having a reduced uterine development and the liver fluke adult stage adapting to host populations living at very high altitudes.