"Primary peritoneal hydatidosis is rare. The mechanism of peritoneal infection in such cases is unclear. Dissemination via lymphatics or systemic circulation has been implicated as a possible route 4."
"Secondary peritoneal hydatidosis is almost always caused by hepatic hydatid disease. It is related to seeding from spontaneous rupture of hepatic cyst into the peritoneum or spillage of cyst fluid during surgery. In both instances, depending on the patient's immune response, the sudden release of hydatid antigens into the peritoneal cavity can trigger anaphylaxis. If this does not occur and viable organisms are present, then multiple cysts can develop."