Environmental Contamination by Echinococcus granulosus sensu lato Eggs in Relation to Slaughterhouses in Urban and Rural Areas in Tunisia

Hydatidosis has become a real concern for health care institutions and animal rearers in Tunisia. The Tunisian endemicity is aggravated by the growing number of dogs and the difficulty of getting rid of contaminated viscera because of the lack of equipment in most slaughterhouses. Therefore, microscopic and molecular tools were applied to evaluate the role of slaughterhouses in canine infection and Echinococcus granulosus sensu lato (s. l.) egg dissemination. Exposure risk to E. granulosus s. l. eggs in urban and rural areas was explored in order to implant preventive and adapted control strategies. Microscopic examinations detected taeniid eggs in 152 amongst 553 fecal samples. The copro-PCR demonstrated that 138 of 152 taeniid samples analyzed were positive for E. granulosus s. l. DNA. PCR-RFLP demonstrated that all isolated samples belonged to E. granulosus sensu stricto (s. s.). An important environmental contamination index (25.0%) by E. granulosus s. l. eggs was demonstrated. The average contamination index from the regions around slaughterhouses (23.3%; 95% CI: 17.7-28.9%) was in the same range as detected in areas located far from slaughterhouses (26.0%, 95% CI: 21.3-30.8%). Echinococcosis endemic areas were extended in both rural (29.9%, 95% CI: 24.8-34.9%) and urban locations (18.1%, 95% CI: 13.0-22.9%). The pathogen dissemination is related neither to the presence/absence of slaughterhouses nor to the location in urban or rural areas, but is probably influenced by human activities (home slaughtering) and behavior towards the infected viscera.

Studies on the Protoscoleces and Hooks of Echinococcus Granulosus from Libya by Scanning Electron Microscope.

Introduction: Protoscolex and hook morphology had been used to identify different strains of Echinococcus granulosus. Method: In the present study, hydatid sand was isolated from infected organs such as liver, lung and spleen from slaughtered animals in several abattoirs in the selected study areas in Libya. Scanning Electron Microscope (SEM) was used to describe the outer surface of the Protoscoleces and the hooks. Result: SEM pictures showed different morphological characters of the outer surface of the different parts of the same protoscolex. Also, the buds on the outer surface of brood capsule, and showed some differences between the large and small hooks. These findings appeared the that there was a correlation with significant statistical difference between the measurements of large as well as small hooks from the same organs of each host as well as between different hosts. Conclusion: Finally, it was difficult to determine whether these cases are not real distortions in the morphology of E. granulosus. They possibly could be caused by mutation or related to a special strain of E.granulosus. Thus, the findings of the present study would suggest that there is a need to consider relationships between the different characters of hooks with different strains of E.granulosus.