Echinococcus granulosus and other intestinal helminths in semi-stray dogs in Tunisia: infection and re-infection rates.

Objective: Assessing the baseline prevalence and the re-infection rate of E. granulosus and other cestodes in dogs is important for a control program based on regular dog dosing treatment with praziquantel mainly to young rural dogs.

Methods: Three hundred and seventy five rural and semi-stray dogs from Jendouba (207 dogs) and Béjà (168 dogs) Departments in Northern-West of Tunisia, were examined to evaluate both the baseline prevalence of intestinal helminths and re-infection rates with Echinococcus granulosus and other cestodes. Parasites were collected in faeces following arecoline hydrobromide purge at the first examination of the dogs and at 4 intervals of reexamination: 2, 4, 8 and 12 months. After each examination, dogs were treated with praziquantel.

Results: The global baseline prevalence with Intestinal helminths in dogs was about 35 %. E. granulosus and other helminths were found in 3.5% (E. granulosus); 9.55% (Taenia hydatigena); 6.36% (Taenia pisiformis); 4.77% (Taenia multiceps); 8.59% (Dipylidium caninum), 5.41% (Mesocestoïdes sp.) and Ankylostoma caninum (13.37%). Dogs were re-infected with E. granulosus, T. hydatigena, T. pisiformis and D. caninum, 2 months after the arecoline hydrobromide purge while T. multiceps and Mesocestoïdes sp. infection reappeared 4 months later.

Conclusion: A control program against Cystic/Echinococcosis, based on a regular treatment of the dog population with praziquantel every 60 days seems necessary. However in practice a six-monthly treatment during ten years would must to decrease the infection pressure of E. granulosus and cease transmission for human.