Cystis echinococcosis of 13th century from the Abbey of Badia Pozzeveri

Cystic echinococcosis is a zoonosis caused by Echinococcus granulosus. The life cycle of the parasite develops in the canids, which house the adult tapeworm in the intestine, and in the intermediate mammal hosts. Humans are occasional dead-end hosts, infected by eggs ingestion via fecal-oral route. The larvae from the digested eggs penetrate the human gut wall and are disseminated throughout the body by the blood. The soft tissues involved at the level of the capillaries may host the larvae, and the metacestode, or hydatid cyst, can develop in different organs. The liver is the first organ that the larvae encounter through the blood stream and consequently it is the most frequently involved; it follows the lungs and then the other organs in frequency. The hydatid cyst is a fluid-filled formation that grows centrifugally and that can survive in the intermediate host for years. In ten years, it can growth to a diameter of 15-20 cm. Inside hyaline outer membrane, a cellular germinating layer produces microcystic structures that develop scolices. The scolices pouring out of the cyst develop one or more cysts that can reach every tissue. The life cycle is completed when the definitive host feeds on organs of the intermediate host that contain fertile metacestodes. Death of the germinating layer within the metacestode produces calcification of the cyst wall in the intermediate host. Calcified hydatid cysts found as archaeological finds are generally associated with skeletal remains in the thoraco-abdominal site. In archaeological record, the presence of echinococcosis is underestimated, and the find is relatively rare for the different reasons: 1) difficulty of recognition by the archaeologists; 2) need of accuracy in the excavation and recovery of osteoarcheological remains; 3) fragility of the calcified formation in the soil. Furthermore, the taphonomic alterations can cause the translation from the original site of the calcified formation and undermine the recognition of the organ affected in the living. In Italy there are only two archaeological samples of calcified formation, most probably of echinococcosis origin, described in the paleopathological literature: one from Siena (13th-14th centuries) and one from Abruzzo (early 20th century). In this report we describe another calcified formation found in the archaeological excavation of the monastic site of Badia Pozzeveri, near Lucca, Tuscany, for which we propose a diagnosis of cystic echinococcosis. This finding comes from a privileged lithic coffin built on the northern side of the monastic Church of San Pietro. The grave was used in the 13th century as collective burial by the same laical family group. Calcification is associated with a female individual of about 35-45 years, it was discovered in the thoraco-abdominal region. We propose the diagnosis of hydatid cyst from Echinocossus granulosus based on gross morphology, micro morphology, and a multicomponent approach with Cone Beam Computed Tomography, SEM/EDS and Stable Isotope analysis.