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

<b><i>Introduction:</i></b> The cycle of <i>Echinococcus granulosus</i> 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. <b><i>Patients and Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusion:</i></b> 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.