Fig 1.
Temporal and spatial distribution of the samples.
The pie chart shows the number of samples, the proportion of the sample set and the time period for each of the 17 sites of the study. The groups of samples were collected from sites depicted on the map: Taplow (Maidenhead, A), Vale Crematorium (Evesham, B), Larkhill (Durrington, C), Datchet (Slough, D), Bulford (Salisbury, E), All Saints in the Marsh (York, Roman Fi and High-Late Medieval Fii), Southern Strategic Support Main (Churchill, G), Wentwood Drive (Bleadon, H), North Park Quarry (Bletchingley, I), Peugeot Garage (Canterbury, J), Worcester Cathedral (Worcester, K), Stoke Quay (Ipswich, Anglo-Saxon Li and High-Late Medieval, Lii), Christchurch Priory (Christchurch, M), Chapel Riverside (Southampton, N), Radcliffe Infirmary (Oxford, O), St James (London, P), and Park Street (Birmingham, Q). The map was modified from the NASA SEDAC centre resource: https://sedac.ciesin.columbia.edu/maps/gallery/search?contains=United%20Kingdom.
Table 1.
Key information on the sampled sites and the numbers positive for helminth eggs.
Fig 2.
Prevalence rates of helminths through time.
Prevalence of Ascaris, Trichuris, Taenia and Diphyllobothrium latum for four different time periods (Roman [n = 94], Anglo-Saxon [n = 79], High/Late Medieval [n = 159], and Industrial era [n = 116]). The confidence intervals are calculated using the Wilson Score interval (95% confidence level). Example photomicrographs of parasite eggs from left to right: Ascaris, Trichuris, Taenia and Diphyllobothrium latum Scale bar: 20 μm.
Fig 3.
Variation of Ascaris prevalence rates in different sites.
The prevalence of Ascaris in skeletal individuals from fifteen sites (group size n>1) across the five time periods is displayed with a 95% confidence interval (Wilson Confidence Interval). Sites with very few samples (<10) provide a less reliable estimate for the prevalence and are thus displayed in grey. The sites included are Durrington, DU, Datchet, DA, and Bulford, BU (Late Neolithic/Early Bronze Age); Bleadon, BD, Bletchingley, BY, and Canterbury, CB (Roman); Worcester, WO, and Ipswich (Anglo-Saxon/Early Medieval); Ipswich, IP, York, YO, Christchurch, CC, and Southampton, SH (High/Late Medieval); Oxford, OX, London, LO, and Birmingham, BH (Industrial). The dating range for the sites is visualized by the horizontal bar chart below, with a continuous time axis from the Anglo-Saxon (Early Medieval) to the Industrial periods. The dates for the earliest samples are not displayed as they are labelled Late Neolithic/Early Bronze Age (DU/DA) or Bronze Age (BU).
Fig 4.
Age and Sex-associated effects on prevalence rates for Ascaris.
Samples with associated osteological age were grouped into juveniles (0–12 years old, n = 50) and adults (>13 years old, n = 207) and according to period (A). The prevalence in juveniles was significantly higher in the High/Late Medieval period (Fisher Exact two-tailed p-value 0.02). Individuals where osteological sex was identified (adult individuals only, n = 194 with nfemale = 85 and nmale = 109) were grouped by period (B). No significant differences were identified.