Modelling the transmission dynamics of cystic echinococcosis in donkeys of different ages from Tunisia.

During the period from March 2006 to July 2009 a total of 2040 slaughtered donkeys were examined for cystic echinococcosis (CE). CE prevalence in donkeys was 8.48% and the infection pressure (0.0088 infections per year) and infection rate (0.0448 cysts per year) appeared to be lower than those previously reported for cattle, sheep, dromedaries and goats in Tunisia. However, the number of cysts per infection was relatively high (5.07 cysts per infection). Among the 901 collected hydatid cysts the majority were located in the liver (89.9%), 10.09% in the lungs and 4.77% were fertile (43/901). The amplification of a fragment within the mitochondrial gene coding for cytochrome c oxidase subunit 1 (cox1) revealed that donkeys were infected with both Echinococcus equinus (horse strain, G4 genotype) and Echinococcus granulosus (sheep strain, G1 genotype). E. granulosus G1 developed into fertile cysts (15,112 protoscoleces/ml) with a protoscoleces viability of 65.78%. This investigation is the first detailed epidemiological report on cystic echinococcosis infection in donkeys for any endemic region.