Predictive Factors for Fertility of Daughter Cysts in Hepatic Cystic Echinococcosis and Insights into the Origin of Daughter Cysts.

Introduction: The cycle of Echinococcus granulosus and its developmental potential has always been a subject of debate. While the origin of protoscoleces was well defined, the origin of daughter cysts (DC) was still a contentious topic, and several hypotheses have been proposed. The aim of this work was to study the fertility of DC and its predictive factors in order to determine its origin. Patients and Methods: This was a prospective pilot study including hepatic echinococcal cysts containing DC operated in the Department of General and Visceral Surgery of Habib Bourguiba University Hospital, Sfax, during a 22-month period. A parasitological study of the DC including the determination of their fertility was done. Results: A total of 248 DC collected from 27 multi-vesicular cysts from 21 patients were included in our study. The fertility rate of the DC was 64.5%. Free hooks were present in 130 DC (52.4%) and in only 11(12%) of infertile DC. In a multi-variable analysis, only World Health Organization-Informal Working Groups on Echinococcosis classification type CE2, bilious cyst fluid, number of DC per cyst, cyst size, and DC diameter were factors associated with DC fertility (p < 0.05). Out of 88 infertile DC, 77 (87.5%) were devoid of any hooks. Conclusion: Our findings suggest that most of the analyzed DC were fertile, with fertility associated with factors such as cyst size, DC size, CE2 type, and number of DC/cysts. The absence of hooks in infertile DC questions prevailing theories of their origin.