Epidemiological insights from a large-scale investigation of intestinal helminths in Medieval Europe.

Helminth infections are among the World Health Organization's top neglected diseases with significant impact in many Less Economically Developed Countries. Despite no longer being endemic in Europe, the widespread presence of helminth eggs in archaeological deposits indicates that helminths represented a considerable burden in past European populations. Prevalence of infection is a key epidemiological feature that would influence the elimination of endemic intestinal helminths, for example, low prevalence rates may have made it easier to eliminate these infections in Europe without the use of modern anthelminthic drugs. To determine historical prevalence rates we analysed 589 grave samples from 7 European sites dated between 680 and 1700 CE, identifying two soil transmitted nematodes (Ascaris spp. and Trichuris trichiura) at all locations, and two food derived cestodes (Diphyllobothrium latum and Taenia spp.) at 4 sites. The rates of nematode infection in the medieval populations (1.5 to 25.6% for T. trichiura; 9.3-42.9% for Ascaris spp.) were comparable to those reported within modern endemically infected populations. There was some evidence of higher levels of nematode infection in younger individuals but not at all sites. The genetic diversity of T. trichiura ITS-1 in single graves was variable but much lower than with communal medieval latrine deposits. The prevalence of food derived cestodes was much lower (1.0-9.9%) than the prevalence of nematodes. Interestingly, sites that contained Taenia spp. eggs also contained D. latum which may reflect local culinary practices. These data demonstrate the importance of helminth infections in Medieval Europe and provide a baseline for studies on the epidemiology of infection in historical and modern contexts. Since the prevalence of medieval STH infections mirror those in modern endemic countries the factors affecting STH decline in Europe may also inform modern intervention campaigns.

Population-specific stature estimation from long bones in the early medieval Pohansko (Czech Republic).

OBJECTIVES: We tested the effect of population-specific linear body proportions on stature estimation. MATERIALS AND METHODS: We used a skeletal sample of 31 males and 20 females from the Early Medieval site at Pohansko (Breclav, Central Europe) and a comparative Central European Early Medieval sample of 45 males and 28 females. We developed new population-specific equations for the Pohansko sample using anatomical reconstructions of stature, then compared percentage prediction errors (%PEs) of anatomical stature from limb bone lengths using the derived Pohansko equations with those previously derived from more general European and other Early Medieval samples. RESULTS: Among general European equations, the lowest %PEs for the Pohansko sample were obtained using the equations of Formicola and Franceschi: Am J Phys Anthropol 100 (1996) 83-88 and Ruff et al.: Am J Phys Anthropol 148 (2012) 601-617. However, unexpectedly, the choice between tibial latitudinal variants proposed by Ruff et al.: Am J Phys Anthropol 148 (2012) 601-617 appeared to be sex-specific, with northern and southern variants producing lower %PEs for males and females, respectively. Equations from Breitinger: Anthropol Anz 14 (1937) 249-274, Bach: Anthropol Anz 29 (1965) 12-21, and Sjøvold: Hum Evol 5 (1990) 431-447 provided poor agreement with anatomical stature. When applied to the comparative Central European Early Medieval sample, our new formulae have generally lower %PE than previously derived formulae based on other European Early Medieval samples (Maijanen and Niskanen: Int J Osteoarchaeol 20 (2010) 472-480; Vercellotti et al.: Am J Phys Anthropol 140 (2009) 135-142. CONCLUSIONS: The best agreement with anatomical stature among our newly developed equations was obtained using femoral+tibial length, followed by femoral length. Upper limb bone lengths resulted in higher %PEs. Variation in the tibia is likely to contribute most to potential bias in stature estimation. Am J Phys Anthropol 158:312-324, 2015. © 2015 Wiley Periodicals, Inc.

Daphnia hybridization along ecological gradients in pelagic environments: the potential for the presence of hybrid zones in plankton.

The relative homogeneity of pelagic environments has been regarded as the reason for the absence of hybrid zones for hybridizing planktonic Daphnia (Crustacea: Cladocera); occasional dominance of interspecific hybrids over parental species was explained by their temporal superiority in fluctuating environments. However, water bodies with spatially varying environmental conditions might facilitate the formation of hybrid zones in plankton. We studied the distribution of species and hybrids of the Daphnia longispina complex in 11 canyon-shaped reservoirs, localities characterized by horizontal environmental gradients (particularly of food supply and size-selective predation); we also analysed patterns of carapace size and fecundity among coexisting taxa. Spatial distribution of taxa agreed with their ecological characteristics; those showing different affinities along longitudinal reservoir profiles differed in size according to the presumed fish predation gradient. Only hybrids of Daphnia galeata with Daphnia cucullata and D. longispina (=hyalina) were recorded. The latter two species preferred opposite ends of gradients, such spatial segregation probably explaining the absence of their hybrids. Distributional patterns were relatively stable in two consecutive summers, apart from a substantial decline of D. galeata X cucullata in the second year. The observed pattern of a hybrid-dominated zone in intermediate conditions suggests that local Daphnia hybrid zones may indeed form within reservoirs.