Morphometric study of eggs of Fasciola hepatica treated with Closantel

VICTORIA SOLANA ; ROBERTO MERA Y SIERRA ; GISELA NEIRA ; SILVANA SCARCELLA O.; HUGO SOLANA G

Congreso; International Conference on Parasitology; 2015

Thetrematode Fasciola hepatica is spread worldwide causing important lossesin livestock and is also an expanding zoonotic disease. Chemotherapy isfundamental for its control, yet triclabenzadol resistance is appearing, thusclosantel can be a valid alternative. It is effective against mature and immature stagesyet it does not exhibit ovicidal activity in vitro and the ovicidaleffects in vivo at present are undetermined. TheEgg Hatch Assay is a valid test to evaluate ovicidal activity and wasimplemented to evaluate the effect of closantel; morphometrical study wasincluded as part of the characterization of the treated eggs.  Sheep were inoculated with Cullompton strainof  F. hepatica; eggs wererecovered from the gall bladder of control and closantel treated(subcutaneously and orally) sheep at 12,24, and 36 hours post treatment.Measures were taken on 50 eggs from each were found  in length and size; significant differenceswere detected in width and shape. No statistically significant differences werefound  in length and size between controland experimental groups ; significant differences were detected in width andshape . Eggs exposed to Closantel tend to be more elliptical. It is worthhighlighting that al the length, width and size of the control eggs areconsiderably greater than previous descriptions for  normal F. hepatica eggs in sheep andother domestic and wild species. This could be a characteristic of theCullompton strain,  yet studies should bedone to assess if these large eggs are isolated strains or there is greatervariability in egg morphology than previously supposed.