Evidence for parasites in burials and cesspits used by the clergy and general population of 13th-18th century Ghent, Belgium

Previous research on medieval populations has revealed that differences in lifestyles between groups might lead to distinct parasite infection patterns. This research aims to investigate whether comparable differences can be found in past population groups in medieval, renaissance and early modern period Ghent in Belgium. The material came from town cesspits of Oude Schaapmarkt dated to 13th-14th and 17th-18th century, pelvic sediment from six 13th-18th century burials on the site of Sint-Baafs cathedral, and a 16th-17th century cesspit from the cathedral sacristy used by the clergy. Digital light microscopy and ELISA were performed to detect any parasites present. The eggs of whipworm (Trichuris) and roundworm (Ascaris) were found in all cesspits, and whipworm in two of the burials. Samples from the cathedral sacristy cesspit demonstrated lower egg concentrations than the town cesspits. The protozoa Giardia duodenalis and Entamoeba histolytica were also present, which can cause diarrhoea and dysentery. Our findings suggest that parasites spread by the contamination of food and drink by human faeces dominated in all samples. Overall, whipworm was more common than roundworm, and Giardia more common than Entamoeba. We found no notable difference in the species of parasites found in the clergy and general public. The contrasting egg counts found in the town and sacristy cesspits may indicate a genuine difference in levels of infection between their users, or just that egg preservation in the waterlogged low lying town cesspits was better than in the drier, more elevated sacristy.