image/svg+xml79 X/1/2019 InterdIscIplInarIa archaeologIca natural scIences In archaeology homepage: Thematic review Bioarchaeology of Past Epidemic- and Famine-Related Mass Burials with Respect to Recent Findings from the Czech Republic Hana Brzobohatá a* , Jan Frolík a , Eliška Zazvonilová a,b a Institute of Archaeology of the Czech Academy of Sciences, Letenská 4, 118 01 Prague 1, Czech Republic b Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Viničná 7, 128 44 Prague 2, Czech Republic 1. Osteoarchaeology of epidemic cemeteries Mass burials are reported under diferent contexts and from all time periods. It represents a method for disposing of human remains when there are too many bodies to contend with at one time. Such graves are typically the result of increased mortality due to epidemic, famine, war, genocide, sacrifce, or natural disaster (Beauchamp, 2012; Fornaciari, 2017). To date, many mass graves have been unearthed throughout Europe both in urban and rural contexts and have mostly been attributed to famines and plague epidemics (McIntyre, 2002; Morgan, 2013; Geber, 2014; Bramanti et al. , 2018). The feld of archaeology has greatly benefted from studying epidemic graves, not only through the historical knowledge gained but also through gaining further insight into palaeodemographic dynamics and to answer questions pertaining to palaeopathology (Beauchamp, 2012).Palaeodemographic investigations of past famines have revealed both equal representation of males and females and gender imbalances involving increased female survival, suggesting their higher resistance (McIntyre, 2002; Morgan, 2013). During periods of chronic starvation, the health status of individuals was afected not only by caloric deprivation but also vitamin and mineral defciencies that weaken the body and increase susceptibility to infections. Thus, death from infectious diseases (such as typhus or dysentery) was probably more common than dying from hunger per se (Scrimshaw, 1987; Morgan, 2013). Although children are considered to be most vulnerable, food shortages lasting for months or years are likely to cause skeletal manifestations of malnourishment and generic indicators of systemic stress in all members of afected societies ( e.g. , rickets, porotic orbital lesions, teeth enamel defects, Harris growth arrest lines, periostitis, stunted growth, or vertebral neural canal reduction) (Morgan, 2013; Watts, 2013). It has further been documented that individuals who experienced early life stress were, irrespective of age or sex, likely to be frailer than their peers, and thus were more likely to die during famines (Yaussy et al. , 2016; DeWitte and Yaussy, 2017). Regarding the age structure of past starving populations, medieval Volume X ● Issue 1/2019 ● Pages 79–87 *Corresponding author. E-mail: ARtICLe Info Article history: Received: 7 th May 2019Accepted: 23 rd July 2019 DOI: 10.24916/iansa.2019.1.6 Key words: bioarchaeologyplaguefamineancient DNAMiddle Agesmass burials AbStRACt Irrespective of the reason for breaking usual burial customs, mass graves represent a valuable archive of population data over a short period, and thus ofer a vast amount of information for bioarchaeological research. Herein, we present a selective review of research on past epidemic and famine die-ofs and of new interdisciplinary approaches in this feld of study. We summarize the discoveries of epidemic- and famine-related graves that are temporally and spatially restricted to the medieval/early modern Czech territory, paying special attention to recently unearthed mass burials in Kutná Hora-Sedlec. These burial pits are historically and contextually associated with a famine in the early 14 th century and with the Black Death in the mid-14 th century. To our knowledge, they represent the largest set of medieval mass graves not only in the Czech Republic but also on a European scale.
image/svg+xmlIANSA 2019 ● X/1 ● 79–87 Hana Brzobohatá, Jan Frolík, Eliška Zazvonilová: Bioarchaeology of Past Epidemic- and Famine-Related Mass Burials with Respect to Recent Findings from the Czech Republic 80 samples have shown an increased mortality in non-adults (Geber, 2014), and chronologically younger datasets indicate increased mortality at both extremes of the age spectrum, i.e. children and in elderly persons (Morgan, 2013). As for the epidemic mortality, the most lethal killer – plague – was not selective for sex and male/female ratios of plague burial grounds did not signifcantly difer from pre- and post-epidemic cemeteries (Signoli et al. , 2002; De Witte, 2009). Less frequently, excess female mortality was documented in both urban and rural contexts (Curtis, Roosen, 2017). Another of the factors explored and potentially impacting plague mortality profles was age- at-death, and DeWitte (2010a) has shown that older adults showed somewhat higher risks of dying during the epidemic compared to the younger. In general, two diferent types of mortality can be found in skeletal assemblages: catastrophic and attritional (Margerison, Knüsel, 2002). A high percentage of infant deaths, a low number of adolescent deaths, and an increasing mortality rate throughout adulthood would be consistent with attritional (normal) mortality, while an increased risk of death occurring in all age categories refects a short-term catastrophe (Gowland, Chamberlain, 2005). If the population was afected by an epidemic, deceased individuals were often buried in mass graves because there was not the time, nor space to bury them individually. If the epidemic killed people indiscriminately regardless of age and sex, then the mass graves would represent an unbiased sample of the population. However, the results of diferent studies ( e.g. DeWitte, 2010b; Galanaud et al. , 2015; Crespo, Lawrenz, 2016) have shown that this is not the case, but rather, that susceptibility to death varies during sudden events such as epidemics, which have been referred to as heterogeneity in frailty (Wood et al. , 1992). Recent research has indicated that one of the worst demographic crises, the Black Death, caused selective mortality and removed the frailest of the population (DeWitte, 2016). The concept of frailty, defned as a state of decreased resistance to stressors (Fried et al. , 2001), has been discussed in several recent bioarchaeological studies (DeWitte, Wood, 2008; DeWitte, 2010b). Factors typically used to evaluate frailty in epidemiological research are generally not observable in skeletal remains. In archaeological populations, only skeletal and dental indicators of stress indicate pathological conditions in an individual. Marklein et al. (2016) proposed a method based on assessing the frailty of living populations applicable to bioarchaeological populations, the skeletal frailty index (SFI). This method provides a frailty score for everyone in a population based on the presence or absence of 13 skeletal and dental indicators. This method should provide a better understanding of the overall health of past populations rather than simply measuring mortality (Marklein et al. , 2016).Demographic composition and indicators of skeletal stress are essential for better understanding health and mortality. By comparing the prevalence of stress indicators ( e.g. cribra orbitalia, linear enamel hypoplasia, periosteal new bone formation) in individuals buried in attritional (normal) and mass graves, the level of stress and risk of death can be determined. Higher prevalence of stress lesions would be expected in mass graves. However, the relationship between stress lesions and mortality is not straightforward, demonstrating the osteological paradox phenomenon (Wood et al. , 1992; DeWitte, Stojanowski, 2015). The presence of stress lesions does not necessarily mean that the individual was healthier compared with those without lesions, but rather, some individuals without stress lesions died before the stress was refected in the skeleton. The most detectable skeletal markers require several weeks to form; thus, we can assume that individuals with lesions must have at least survived this long. Bone is slower to respond to the efects of stress than soft tissue. Therefore, the presence of stress indicators indicates severe or prolonged stress. Instead of comparing the prevalence of skeletal stress indicators, they should be evaluated in terms of mortality and their efect on survivorship (Temple, Goodman, 2014). In the case of mass graves, cultural or historical context can help to understand whether individuals with a higher prevalence of stress were frailer. Although the demographic composition of a population sufering a disease epidemic difers from that of a non-epidemic population, some factors can infuence the age distribution of examined samples. Taphonomic factors that infuence infant skeletal remains can make them invisible in the archaeological record, consequently biasing the fnal distribution. When historical and cultural conditions are unknown and only demographic composition is available as evidence of a demographic crisis, diferences in skeletal preservation may distort results to resemble attritional mortality (Margerison, Knüsel, 2002; Kyle et al. , 2018). Ageing presents further problems in bioarchaeological research. Poorly preserved skeletons, systematic underestimation of old individuals, or circumstances afecting skeletal aging, are some of the factors that complicate the estimation of age at death of adults (Cave, Oxenham, 2016). Furthermore, inconsistency in the use of age-estimation methods causes problems when comparing burial grounds, or their apparent normal mortality (Bramanti et al. , 2018). Nevertheless, by combining methods from social and biological sciences in the study of historical mass graves, we can more thoroughly interpret the information held in the bones and, thanks to this transdisciplinary approach, better reconstruct daily life in times of catastrophes. 2. Difculties in retrospectively diagnosing infectious diseases Previous studies of ancient disease episodes have largely relied on historical and archaeological data alone, such as skeletons, mummifed remains, ancient texts, church records, burial registers, and art works (Mitchell, 2011; Signoli, 2012; Smith et al. , 2012). However, the most common infections of these times are osteologically invisible, and written records are often inaccurate. Thus, it is not possible to come to a
image/svg+xmlIANSA 2019 ● X/1 ● 79–87 Hana Brzobohatá, Jan Frolík, Eliška Zazvonilová: Bioarchaeology of Past Epidemic- and Famine-Related Mass Burials with Respect to Recent Findings from the Czech Republic 81 modern biological diagnosis for many past epidemics. By medieval times most of the acute infectious diseases were universal in the Old World and had settled into distinct cycles of epidemics, mainly afecting young children (Crawford, 2007). Considering key environmental and epidemiological factors of medieval towns, nearly all microbial and viral transmission routes were facilitated by poor sanitation conditions, contaminated water, and overpopulation. Although many of the worst pre-industrial epidemics appear to have been caused by the bubonic plague, the range of epidemics that are referred to as “plagues” is much larger (Alfani, Murphy, 2017). The causes of epidemics referred to as “ peste ” or pestilential ” by contemporaries must be investigated separately because it cannot be assumed that a ‘‘plague’’ in one place was due to the same specifc microbial agent as those in other places, even during the Black Death (Carmichael, 2008). In particular, populations weakened by malnutrition/starvation could have easily succumbed to infuenza, typhus, dysentery, smallpox, typhoid fever, relapsing fever, or another highly-transmissible pathogen (Smith et al. , 2012; Andam et al. , 2016; Guellil et al. , 2018).For a long time, the most interesting topic concerning the scholars researching historic epidemic assemblages has been determining the causative organism of the bubonic plague (Beauchamp, 2012). The most likely pathogen to account for the plague epidemics is Yersinia pestis . The actual aetiology of this disease has long been controversial, and a group of researchers have argued in favour of other potential microbial agents of the medieval episodes of great mortality. Alternative hypotheses included bacillus anthracis (Twigg, 1985), a flovirus, or a pathogen that is now extinct (Scott, Duncan, 2001; Cohn, 2003; Duncan, Scott, 2005). They argued that: the diferences between the Black Death and current manifestations of the plague are too great to have the same aetiology (Cohn, 2002); the epidemiological dynamics of the medieval Black Death based on historical records were consistent with a viral pathogen spreading as an aerosol or through direct contact between persons (Bossak, Welford, 2009). Other inconsistencies have been pointed out by sceptics, including those between the clinical and epidemiological characteristics of plagues in historical records and those observed in India in the early 20 th century (Scott, Duncan, 2001; Cohn, 2002).Controversies regarding the cause of the plague were resolved by examining the samples taken from bodies buried during the Second Plague Pandemic (14 th –18 th centuries) with molecular biology techniques. Since fnding the presence of Y. pestis in European plague assemblages, both palaeoimmunological (Bianucci et al. , 2009; Kacki et al. , 2011) and genetic ( e.g. Haensch et al. , 2010; Seifert et al. , 2013; Spyrou et al. , 2016) approaches have been successfully introduced. However, presumptive epidemic victims should also be examined in terms of co-morbidities and co-mortalities of plague contemporaries, because the concurrent presence of a plurality of infectious diseases cannot be excluded (Papagrigorakis et al. , 2006; Tran et al. , 2011). Such an example has been provided by Tran et al. (2011), who detected DNA from both Y. pestis and bartonella quintana (causing trench fever) in dental pulp harvested from the same medieval mass grave in Bondy, France. Not only were the microbes detected in the same mass grave, but even in the same individuals. Another problem of retrospective diagnosis was demonstrated in the study of Papagrigorakis et al. (2006) regarding the DNA of the causative agent of the Plague of Athens (430 BC). This epidemic has traditionally been considered to be an outbreak of the bubonic plague. However, contrary to written records, the authors of the study proposed typhoid fever as a probable cause of the mass die-ofs.Much palaeomicrobiological data, while confrming that some burial sites in medieval Europe were plague burial pits, do not help resolve the remaining questions concerning the epidemiology of the Black Death. Vast amounts of the plague literature are therefore focused on the issues of primary reservoirs, disease vectors, and epidemiologic spread, in which there remain signifcant areas of debate (Gage, Kosoy, 2005; Tran et al. , 2011; Yue et al. , 2017). 3. Genetic investigations into the causative pathogens of medieval and early modern mass die-ofs The most informative method to establish the etiological nature of the ancient infections should be the analysis of ancient DNA (Haensch et al. , 2010). DNA techniques targeted at genomic parts of pathogens in human remains are quite expensive and cannot be employed indiscriminately. For this reason, their use should be restricted to burial sites at which there are serious indications of a mortality crisis unconnected to a massacre or act of war (Duday, 2008). Because plague was responsible for the worst mortality crises of the medieval and early modern period (Alfani, Murphy, 2017), Yersinia pestis is the pathogen which has been most frequently collected, sequenced, and studied in a historical context (Andam et al. , 2016). While the detection of this pathogen in today’s plague victims can be achieved without major difculties, the detection in ancient samples, such as skeletons, is crucial (Seifert et al. , 2013). Despite the relevance of genetic investigations into ancient epidemics, for a long time major breakthroughs have been rare and the feld has been subject to recurrent scepticism regarding the authenticity of results, poor precautionary measures, faulty methodology, and possible contamination (Wilbur et al. , 2009; Callaway, 2011; Knapp, 2011). However, recent improvements in contamination control, workfow design and the emergence of new sequencing technologies have dramatically shifted the possibilities of the identifcation of all the ancient pathogens. In 1998, a nucleic-acid based confrmation of ancient plague was achieved for historically-identifed French plague victims dated to 16 th and 18 th centuries (Drancourt et al. , 1998). Later, in 2000, Raoult et al. recovered Y. pestis DNA from the teeth of individuals dug up from the 14 th century mass grave in Montpellier, France. Contrary to these early
image/svg+xmlIANSA 2019 ● X/1 ● 79–87 Hana Brzobohatá, Jan Frolík, Eliška Zazvonilová: Bioarchaeology of Past Epidemic- and Famine-Related Mass Burials with Respect to Recent Findings from the Czech Republic 82 successful detections, another team found no trace of plague bacterium DNA in 108 teeth from 61 individuals found in plague pits in France, Denmark and England (including East Smithfeld) (Gilbert et al. , 2004). Further updating and refnement of molecular investigation techniques has soon brought more informative results and constituted molecularly-supported confrmation for the etiologic agent of plague in mass graves in northern, central and southern Europe (Haensch et al. , 2010). A scientifc breakthrough was reached in 2011 with the publication reporting a whole genome sequence of Y.pestis from Black Death victims securely dated to episodes of pestilence-associated mortality in London, England, 1348– 1350 (Bos et al. , 2011). The same osteological material (but analysed by Schueneman et al. in 2011) permitted reconstruction of the full pPCP1 virulence-associated plasmid at high coverage. These data revealed that the Black Death in medieval Europe was caused by a variant of Y. pestis that may no longer exist, and genetic data carried on its pPCP1 plasmid were not responsible for the epidemiological diferences between ancient and modern forms of Y. pestis infections. Based on the aforesaid results and the growing body of evidence implicating this bacterium as responsible for the medieval pandemic, the authors believe scientifc debates should now shift to addressing the genetic basis of the epidemic’s unique characteristics (Schueneman et al. , 2011).Seifert et al. (2013) developed a robust ancient DNA workfow to detect plague bacterium in skeletal remains, consisting of optimized sample preparation in combination with thoroughly validated quantitative screening PCR (polymerase chain reaction) assays. In the ensuing study, the researchers sought to fnd an answer to one of the most challenging questions concerning the plague: how the pandemic could have continued in Europe for several hundred years. Previous genotyping results suggested that the plague was imported to Europe from Central Asia on at least two occasions by distinct trading routes (Haensch et al. , 2010). Seifert et al. (2016) recovered DNA from plague victims from German burial sites spanning a time period of more than 300 years (from 14 th to 17 th century) and identifed at least one genotype which was introduced to Europe in the mid-14 th century and persisted here until the Thirty Years’ War (1618–1648). Accordingly, they suggest a model in which Y. pestis was introduced to Europe in several waves combined with a long-term persistence of the pathogen in not yet identifed reservoirs. The genetic link between the medieval and post–medieval European plague outbreaks and the existence of now-extinct European plague foci were also supported by results of Spyrou et al. (2016). Research on this devastating pathogen is now moving to re-analyses and re-evaluations of previously published genomes and using state-of-the-art bioinformatics methods to revise its phylogeny and transmission dynamics (Namouchi et al. , 2018). 4. Suspected epidemic and famine cemeteries from the Czech territory Analysis of osteological assemblages from past catastrophes should cover as many archaeological sites as possible (Castex, 2008). Here, we review several medieval and early modern funerary deposits and plausible archaeological evidence of epidemic- and famine-related mass die-ofs from the territory of the current Czech Republic (Figure 1).Mass graves represent an attractive part of archaeological investigations not only for archaeologists and anthropologists, but also for the general public. However, a deeper archaeological comprehension is still in its infancy. Such fndings are usually associated with war events, as a resting place for either the fallen soldiers or civilian casualties. In the Czech territory, cases are commonly dated to the Hussite Wars or the Thirty Years’ War. In the Moravian region, the Figure 1. Location of presumed epidemic- and famine-related mass graves in the Bohemia and Moravia quoted in the paper: 1 – Prague, Lesser Town, the Church of St. John at the Laundry; 2 – Kutná Hora – Sedlec, Cemetery Church of All Saints with Ossuary; 3 – Pardubice – Pardubičky, extinct Cyriac Monastery; 4 – Boleradice; 5 – Olomouc, the Church of St. Moritz; 6 – Uherský Brod, the Church of Master Jan Hus; 7 – Ostrava, Kostelní Square.