Two cases of cystic echinococcosis reported from al-Andalus cemeteries (southern Iberia): Insights into zoonotic diseases in Islamic Medieval Europe

The identification of a calcified hydatid cyst in the bioarcheological record is key to the diagnosis of cystic echinococcosis (i.e., hydatid disease), a parasitic infection caused by the tapeworm Echinococcus granulosus. This zoonosis can be linked to human–canid interactions, given the reproductive cycle of the parasite (from canids to herbivores/humans as intermediate hosts), and it is commonly associated with agropastoral communities in both the past and present. However, it is not easy to identify a calcified hydatid cyst in the archeological record because of preservation problems and its similarity with other calcifications of biological and geological origin. We report the presence of two fragmented ovoidal calcified formations associated with human remains in different medieval Islamic cemeteries from the Kingdom of Granada in al-Andalus (Southern Iberia, 13th–15th centuries AD). These formations were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The localization, morphology, and composition of the calcifications indicate that they are hydatid cysts caused by E. granulosus, representing the first evidence of cystic echinococcosis in Islamic Medieval Europe. Our results are in line with archeological and historical records of human–animal interactions and agropastoral practices in al-Andalus, and they highlight the importance of analyzing calcified masses in the osteoarcheological record.