Cystic echinococcosis in Tunisia: analysis of hydatid cysts that have been surgically removed from patients.

Echinococcosis/hydatidosis caused by Echinococcus granulosus has a widespread distribution in the human population of Tunisia, particularly in the north-west and centre-west of the country. In a recent study, the morphological features, fertility and viability of hydatid cysts that had been excised from patients in Tunis were explored, and the E. granulosus strain or genotype involved in each case was identified from morphology of the protoscolex hooks and the results of molecular genotyping. The hepatic cysts investigated came from 41 patients [31 women and 10 men, with a mean (S.E.) age of 43.41 (14.25) years] who were treated for cystic echinococcosis, by surgery but rarely with chemotherapy, at the La Rabta Hospital in Tunis, in the 12 months ending in June 2008. Most (56%) of these patients originated from rural areas in endemic governorates. Of the 60 hepatic cysts that were studied, 38.3% were located in the right lobe of the liver and 35.0% each involved both hepatic lobes. Almost a third (31.7%) of the excised cysts were degenerating, with the rest considered viable and either multivesicular (38.3%) or univesicular (30.0%). Almost all (93.3%) of the cysts were categorized as fertile, with a mean protoscolex viability of 21.8%. Protoscolex viability was relatively high in the viable univesicular cysts with a visible cyst wall and in the multivesicular and multiseptate cysts with daughter cysts, and lowest in the cysts that appeared to be solid calcified masses. The observed variation in protoscolex viability with cyst type, in cysts excised from patients before any chemotherapy, supports the cyst classification recommended by the World Health Organization but could also be compatible with the imaging-based 'Gharbi' classification. The results of the molecular genotyping showed that all 23 cysts investigated (which came from 20 of the patients) were caused by E. granulosus of the G1 genotype (also known as the 'sheep' or 'sheep-dog' strain).

Echinococcus in the wild carnivores and stray dogs of northern Tunisia: the results of a pilot survey.

Echinococcus granulosus is endemic throughout Tunisia and E. multilocularis has previously been reported as the cause of two cases of human alveolar echinococcosis in the north-west of the country. The aim of the present study was to screen wild carnivores from the north-western Jendouba governorate and semi-stray dogs from the Siliana and Sejnane regions of northern Tunisia for these two zoonotic cestodes. The results of the coproscopy, coproELISA and coproPCR that were undertaken were compared with those of necropsy, where possible. Overall, 111 faecal samples (51 from wild carnivores and 60 from stray dogs) were tested by coproELISA for Echinococcus antigen and by coproPCR for E. granulosus and E. multilocularis species-specific DNA. All 60 dogs and seven of the wild carnivores were necropsied. Eleven (18.4%) of the dogs and one golden jackal (Canis aureus) were found positive for E. granulosus at necropsy. The jackal was found to be carrying 72 E. granulosus tapeworms, which were confirmed to be of the common sheep-dog (G1) genotype. Faecal samples from 10 (19.6%) of the wild carnivores--putatively, four golden jackals, two red foxes (Vulpes vulpes atlantica), one hyaena (Hyaena hyaena) and three genets (Genetta genetta)--gave a positive result in the Echinococcus coproELISA. In the coproPCR-based follow-up, E. granulosus DNA was detected in faecal samples from five jackals, two foxes and six stray dogs. The DNA of E. multilocularis was not, however, detected in any of the faecal samples investigated. This is the first report from Tunisia of (coproPCR-)confirmed E. granulosus infections in golden jackals and red foxes. The possible role of such wild hosts in the transmission of E. granulosus in Tunisia should be investigated further. The possibility of the active transmission of E. multilocularis in Tunisia still remains an open question.