Investigating the association between intestinal parasite infection and cribra orbitalia in the medieval population of Cambridge, UK.

OBJECTIVE: Cribra orbitalia is believed to be a skeletal indicator of chronic anaemia, scurvy, rickets or related metabolic diseases. It has been suggested that it may be used as a proxy indicator for intestinal parasite infection, as parasites often cause anaemia today. Our aim is to investigate this association in the medieval population of Cambridge, UK. MATERIALS: Individuals excavated from the cemeteries of the Augustinian friary and All Saints by the Castle parish church, and aged from 7 to adulthood. METHODS: We undertook parasite analysis of the pelvic sediment and control samples of 46 burials with intact orbital roofs. RESULTS: Human roundworm (Ascaris lumbricoides) and/or whipworm (Trichuris trichiura) were identified in the pelvic sediment of 22 individuals, and cribra orbitalia noted in 11 individuals. Barnards test showed no association between parasite infection and cribra orbitalia (p = .882). CONCLUSION: We found no association between infection and cribra orbitalia infection in this medieval adult population, calling into question this hypothesis, at least for adults. SIGNIFICANCE: High or low cribra orbitalia prevalence in adults should not be used to infer rates of intestinal parasite infection. LIMITATIONS: The individuals in the study were over the age of 7, with no younger children. It is possible that only parasites which cause marked anaemia (such as hookworm, schistosomiasis or malaria) may cause cribra orbitalia, while less marked anaemia from roundworm and whipworm may not do so. SUGGESTIONS FOR FURTHER RESEARCH: Repeating this study in younger children, when most cribra orbitalia appears to form.