Category Archives: Axis II – History of Plague

Molecular Traces of the Black Death

Over the last decade a substantial amount of molecular evidence confirming the etiology of the plague over virtually the entire medieval period has been produced. In this rapidly evolving field, evidence for the Black Death of the 14th century has been produced by each new method in turn.

Given the conditions of remains sampled to date, the methods fall into two main categories: genomics and immunology. There are pros and cons to each. Genomics has well-recognized specificity and the ability to compare with living and ancient strains, but non-nucleic acid methods are both specific and far more sensitive. Non-nucleic acid methods (using immunology) will give a better indication of the true incidence within a population, especially important when testing moves beyond mass graves. Immunologic methods have been the primary means of diagnosing clinical infectious disease for at least 30 years. The Rapid Diagnostic Test (RDT) now used to diagnose ancient and modern plague uses technology that has existed for over 25 years with a good track record. The downside of immunology is that it doesn’t give strain specific information. On the other hand, detection of degraded DNA much less getting good enough sequence for strain matching is difficult and inefficient.

This map charts all of the medieval plague molecular data that I have seen (view Plague Map in a larger map). The red balloons mark 6th-9th century, Plague of Justinian, sites. All three early medieval sites are beyond the Alps proving that the plague of Justinian penetrated well beyond the Mediterranean basin.  The yellow balloons represent 14th century data, with the starred balloon specifically dated to the first wave of the Black Death pandemic. The blue balloons represent post-14 century data (14th-17th century). Click the balloons for references.

Even a cursory look at the map makes it apparent that both pandemics reached beyond the Alps into the European plain. Further, the distribution represents the areas of activity of 3-4 research groups rather than as an indication of plague incidence across Europe. Every region so far examined and published has found some evidence of plague. There is both DNA and immunological evidence for the 14th century. Unfortunately, DNA data has been produced by three different groups who have not yet produced a consensus sequence or analyzed their differences. Despite the differences between their sequences, there is plenty of homology between their data and modern reference sequences to ensure that they all identified Yersinia pestis. Their differences are most likely to be primarily related to interpretations of degradative changes in the ancient DNA, though it is possible that more than one strain was active in 14th century Europe.

The map also makes it apparent that we only have molecular evidence from a very small sliver of the territory covered by the medieval pandemics. There are too few sites so far to make any predictions about the routes the plague traveled based on molecular evidence. It never travels from point A to point B as the crow flies! Plague spreads more like a spiderweb than a wave. So, long distance transmission may well exist before lateral spread fills in the countryside. It is absolutely necessary to take in consideration medieval trade and communication routes.

This is an exciting time to be working on the plague. So far, only the tip of the iceberg has been exposed. To date, the molecular evidence has been the most useful for confirming the etiology of the plague of Justinian, the Black Death pandemic, and plague’s endurance in western Europe. We have the technology now to map the geographic extent of Yersinia pestis for the first and second pandemic. It will take at least a generation of work from archaeologists, geneticists, and paleomicrobiologists to gather enough sites and resolve the fine-detail sequencing issues to begin to do strain mapping.

 

Remapping the Black Death in the Age of Genomics and GIS

127th annual meeting of the American Historical Association, January 2013 at New Orleans

http://aha.confex.com/aha/2013/webprogram/Session7774.html with abstracts of the papers

http://contagions.wordpress.com/2012/09/19/aha-2013-the-power-of-cartography-remapping-the-black-death-in-the-age-of-genomics-and-gis/

Remapping the Black Death in the Age of Genomics and GIS will be an important topic, as many maps showing the spread of the Black Death still use 19th c.’s data collection, which often do not refer to the sources properly. And in many cases they just seem to use evidence of pogroms as a real evidence for the Black Death.

Invitation to the Black Death Network

Dear colleagues,

The blog “The Black Death Network. Interdiscplinary approaches to the 14th-century crises in Europe ” just started. This is an initiative arising from a session at the EAA European Association of Archaeologists)/  MERC (medieval Europe research Congress) meeting in Helsinki 2012.
If you are engaged in research connected to the 14th-century crises across Europe we would be very happy for you to join out network. Our aim is to connect students and experienced scholars from all disciplines, to exchange news and ideas and to discuss all aspects of the topic.

We will give all colleagues author rights to write and comment. Please write an email to schregATrgzm.de or some other member of the editorial team. However, we ask you for a introductory blogpost presenting your yourself and your interests in the topic. We sort these posts in a category “researchers” which will create an overview of all persons actively involved. You may post short information about your research, new publications, news on relevant conferences.

The blog is hosted at hypotheses.org/ openedition, a common platform for academic blogs organised by the German Historical Institute at Paris, the French National Library. They will provide a ISSN similar to a journal and will also take care for archiving of the blog. Blog-Posts are therefore a litte bit more official than in private blogs, and therefore can also be cited. We put the texts of the blog under a CC-licence (BY NC SA).

You can follow the blog by rss-feed or by joining the facebook-group “The Black Death Network”. https://www.facebook.com/groups/340262089399227/. New posts from the blog are connected with this fb-group by an rss-feed.

There is also a group The Black Death Network at zotero collecting bibliographical data of research publications as well as more popular articles.

Rainer Schreg
Richard Thomas
Kerstin Pasda
Cclare Downham

DNA finds of Yersinia pestis

Several studies have dealt with the idenficiation of aDNA of Yersinia pestis. There are several arguments for a mutation of Y. pestis shortly before the 1347-53 pandemic. Probably there were different variants of Y. pestis involved. In order to understand the historical ecology of the Black Death and the role of 14th-century land-use practices and climate changes it will be crucial to trace the development of Y. pestis .

To date Y. pestis has been extracted from human skeletal remains at the following locations:

 
Yersinia pestis – larger map
(additions are welcome)

The Black Death Network

The 14th century AD was a profoundly tumultuous period in European history. Climatic deterioration in the first quarter of the century triggered harvest failures and human famine in a population that had already exceeded the carrying capacity of agricultural production. Human famine was compounded by the widespread loss of cattle and sheep as epizootics spread across the continent. In many parts of Europe, continuous warfare and the consequential increased burden of taxation further stretched agricultural production to breaking point. In the middle of the century the Black Death swept through Europe killing 30–60% of the population. These calamitous events had profound social and economic repercussions that resonated far beyond the immediate aftermath of the population crash in the late 1340s and early 1350s.

Understanding of the 14th-century crises needs:

– a broad interdisciplinary approach, bringing together humanities and sciences;
– a comparative approach to enable the examination of different landscapes with their distinct historical and ecological background.

An ecological perspective on a local or regional scale may help to understand the specific causes and effects. It may help to overcome deterministic interpretations and to deal with the complexities of the 14th centuries crises and the human responses to them.

Some of the disciplines involved are:
– History
– Medieval archaeology
– Zooarchaeology
– Archaeobotany and palynology
– Physical anthropology
– DNA studies
– Stable isotopes
– Geoarchaeology
– Entomology
– Dendrology
– Meteorology

Understanding of the 14th-century crises needs:

a broad interdisciplinary approach, bringing together humanities and sciences;
a comparative approach to enable the examination of different landscapes with their distinct historical and ecological background.

An ecological perspective on a local or regional scale may help to understand the specific causes and effects. It may help to overcome deterministic interpretations and to deal with the complexities of the 14th centuries crises and the human responses to them.

Some of the disciplines involved are:

History

Currently our knowledge on the 14th-century crisis is mainly based on written evidence. Besides chronical reports of famines, plagues and weather extremes, there are also data on prices of grain for example, which may reflect not only local policy but also supraregional crop failure. To understand the crises we need detailed analysis of specific local case studies.
Historical and medieval studies are crucial to understand perceptions and explanations of the plague and other 14th c.’s hazards by contemporaries.

Medieval archaeology

Already for some decades medieval archaeologists have been interested in the phenomenon of abandoned settlements, which have been in many cases connected with the 14th-century crises. However, to understand the changes in settlement pattern we need to broaden our perspective by looking more closely at existing settlements as well as land use patterns.

Zooarchaeology

In England and Germany, zooarchaeological evidence (the study of animal bones from archaeological sites) is beginning to reveal that significant changes in dietary identities and agricultural production occurred during the 14th century and testify to changes in the patterns of land-holding, land use practices, and rising living standards. Analysis of animal bones can also identify the distribution of the black rat (Rattus rattus).

Archaeobotany and palynology

Whereas in some landscapes reforestation during the late medieval period is visible in palynological (pollen) data , in many cases such evidence is missing. Quite often, the interest of palynological studies has instead focussed on prehistoric periods or has not produced data with the chonrological precision to explore environmental and climatic change in the 14th century. Archaeobotany (the study of macrobotanical remains) also has the potential to explore the changing nature of diet and land practice, although this remains an under-explored avenue of enquiry.

Physical anthropology

The analysis of human skeletal remains has proven potential to shed light on morbidity and mortality rates in populations before and after the Black Death, through the analysis of stature, stress indicators, and disease. The context of deposition also provides indications of how survivors dealt with mass mortality events, and in some cases it is possible to extract and detect the bacterial pathogen through aDNA analysis.

DNA studies

Ancient and modern DNA studies enable the detection of causative pathogens, when found in human skeletal remains, but also make the evolutionary history of germs, such as Yersinia pestis possible to trace.

Stable isotopes

Analysis of stable isotopes of carbon and nitrogen from human and animal remains make it possible to track the changing nature of human and animal diet before and after the Black Death. Some stable isotopes, such as oxygen, can be used to detect climatic change, while others (e.g. Strontium) have the potential to track the movement of people and livestock.

Geoarchaeology

The effects of heavy weather effects and land use practices can be detected through the analysis of soils and sediments. In many regions of western Central Europe geoarchaeology proved massive soil erosion during the 14th century. Probably especially the St. Mary Magdalene’s flood in July 1342 caused massive gullying.

Entomology

An analysis of preserved insect remains can help to detect micro-and macro-environmental changes. Furthermore it maybe possible to identify fleas, important for the spread of plague.

Dendrology

Analyzing tree rings allows detailed reconstructions of weather and climatic conditions. This is essential for the understanding of the 14th Century as a transition period from the Medieval Warm Period to the Little Ice Age.

Meteorology

Meteorological expertise is especially important for understanding the causes and impact of extreme weather events of the 14th Century demand. This raises the question to what extent, for example, changes in land use in the Middle Ages had an influence on the risk of thunderstorms and heavy rain.

Some of these disciplines have contributed important research, however, others are just beginning. Basically it is to relate the knowledge of the different subjects together.
The Black Death Network grew out of a session of the Conference of the European Association of Achaeologists (together with Medieval Europe Research Conference MERC) 2012 in Helsinki, Finland.

Sickness, Hunger, War, and Religion

As open access available:
“Sickness, Hunger, War, and Religion: Multidisciplinary Perspectives.”
Rachel Carson Center Perspectives 2012, Issue 3
Edited by Michaela Harbeck, Kristin von Heyking, and Heiner Schwarzberg

A peste, fame et bello libera nos, Domine!” Disease, hunger, war, and religion have shaped human existence over many centuries. This volume presents exciting syntheses between research in the fields of archaeology, anthropology, and history; moving from prehistory to the medieval period, six chapters look at humanity’s struggles with subsistence, religious belief, ill-health, death, and warfare in a variety of global landscapes, and show how, by sharing expertise and combining methodological approaches, we can advance our understanding of our common past.


http://www.carsoncenter.uni-muenchen.de/publications/perspectives_mainpage/2012_perspectives/index.html

available as  pdf (pdf, 7.5 MB) (or printer-friendly version, pdf, 6.6 MB)

Human skeletal health before and after the Black Death

Ongoing analysis of the human skeletal remains from London by Sharon DeWitte reveals changes in health and lifespan in the wake of the Black Death, and adds to the growing body of bioarchaeological evidence that life for survivors was better.

http://archaeologynewsnetwork.blogspot.co.uk/2012/09/decoding-black-death.html

Yersinia pestis – the missing ecological and historical dimension

Reposted from http://archaeologik.blogspot.de/2011/11/yersinia-pestis-missing-ecological-and.html

Yersinia pestis, Direct Fluorescent Antibody Stain (DFA),
200x Magnification
(Centers for Disease Control and Prevention‘s
Public Health Image Library [PHIL],
identification number #1918 [public domain]).
In a recent article a group of German and Canadian researchers presented the genome of Yersinia pestis as it has been extracted from burials of the London East Smithfield burial ground dated to 1348/49 (Bos et al. 2011). This site has been excavated by the Museum of London after it has been localised in 1986 (Grainger et al. 2008).
The article aims at the reconstruction of the ancient genome of Yersinia pestis, as this promises implications for the understanding of infectious diseases, as “genomic data from ancient microbes may help to elucidate mechanisms of pathogen evolution and adaptation for emerging and re-emerging infections”.
The authors conclude:
1.) “Genetic architecture and phylogenetic analysis indicate that the ancient organism is ancestral to most extant strains and sits very close to the ancestral node of all Y. pestis commonly associated with human infection. Temporal estimates suggest that the Black Death of 1347–1351 was the main historical event responsible for the introduction and widespread dissemination of the ancestor to all currently circulating Y. pestis strains pathogenic to humans.” The classic Black Death was quite different from previous epidemics. The authors refer to the Justinian plague “popularly assumed to have resulted from the same pathogen: our temporal estimates imply that the pandemic was either caused by a Y. pestis variant that is distinct from all currently circulating strains commonly associated with human infections, or it was another disease altogether.”
2.) “Comparisons against modern genomes reveal no unique derived positions in the medieval organism, indicating that the perceived increased virulence of the disease during the Black Death may not have been due to bacterial phenotype. These findings support the notion that factors other than microbial genetics, such as environment, vector dynamics and host susceptibility, should be at the forefront of epidemiological discussions regarding emerging Y. pestis infections.”