The aim of the present study was to test histopathologically the hypothesis that the time for clearing Taenia solium cysts in muscle tissue of pigs following treatment with oxfendazole is cyst density dependant. A total of 248 cyst lesions in the masseter muscle of 28 naturally infected pigs were examined 1, 4 and 8 weeks after oxfendazole (OFZ) treatment. As controls, half of the pigs received no treatment. Lesions were graded 0-V according to their inflammatory response, based on viability of the parasite, the degree and type of cellular response as well as deposition of collagen. Comparison of the degree of inflammatory response was made between treated and un-treated groups showing a significant difference in the mean grade of inflammatory response between 1 and 8 weeks after OFZ treatment. The OFZ treated pigs were further divided into 4 cyst intensity groups. The group with the highest cyst intensity had the lowest mean grade of inflammatory response and the group with the lowest cyst intensity had the highest mean grade of inflammatory response. Thus the present study supports the hypothesis that the time needed for the body to clear the cysts depends on the cyst intensity of individual pigs at the time of treatment.
Veterinary Parasitology, 2012, Vol 190, Issue 3-4, p. 442-446