A new study provides data on long-term presence of yersinia pestis from 14th c. onwards by using analysis of ancient DNA (aDNA). The study is based on two different sites in Germany, spanning a time period of more than 300 years. One of them is the 14th c. mass grave at the St. Leonhard church in Manching-Pichl, which is still an extraordinary site in Germany. Of 30 tested skeletons 8 were positive for Yersinia pestis-specific nucleic acid. As there are some significant similarities between the y.p. evidence with other European findings, the authors conclude, that “beside the assumed continuous reintroduction of Y. pestis from central Asia in multiple waves during the second pandemic, long-term persistence of Y. pestis in Europe in a yet unknown reservoir host has also to be considered.”
- L. Seifert/ I-Wiechmann/ M. Harbeck/ A.Thomas/ G. Grupe/ M. Projahn et al.: Genotyping Yersinia pestis in Historical Plague: Evidence for Long Term Persistence of Y. pestis in Europe from the 14th to the 17th Century. PLOS ONE (13.1. 2016). – DOI: 10.1371/journal.pone.0145194 (http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0145194)
In order to understand the 14th c. crisis it will be interesting to see whether their model in which Yersinia pestis “was introduced to Europe from Asia in several waves combined with a long-time persistence of the pathogen in not yet identified reservoirs” is also valid for the time between the 6th and the 14th c. as this has some consequences in understanding possible interaction between landscape changes, extreme weather and the Black Death.