Genomic sequences isolated from individuals who died after the Black Death point to a reservoir of the pathogen Yersinia pestis outside Western Europe that seeded subsequent outbreaks, according to a study. For five centuries after the Black Death, Europe continued to experience outbreaks before a slow decline beginning in the 17th century. To uncover the dynamics of the pathogen, Meriam Guellil, Barbara Bramanti, and colleagues isolated and sequenced nine Y. pestis genomes from individuals in four different regions. Seven of these strains were isolated from individuals who died in the 14th and 17th centuries in Italy, and the other two strains were isolated from individuals who died in the 18th century, one in Scandinavia and one in the Caucasus region. Combining these sequences with previous sequences and historical data, the authors reconstructed the flow of Y. pestis introductions into Europe. Both the Scandinavian and Caucasian genome sequences have a large deletion similar to a strain responsible for the 1722 Great Plague of Marseille. Analysis of historical sources suggest that the strain reached the Chechnya region in a separate introduction, perhaps from a common reservoir. According to the authors, a wildlife reservoir in Eurasia, close to the edge of Europe, may have seeded epidemics.
ARTICLE #20-09677: "A genomic and historical synthesis of plague in 18th century Eurasia," by Meriam Guellil et al.
MEDIA CONTACTS: Nils Chr. Stenseth, University of Oslo, NORWAY; e-mail: n.c.stenseth@ibv.uio.no ; Meriam Guellil, University of Tartu, ESTONIA; e-mail: meriam.guellil.ac@gmail.com ; Barbara Bramanti, University of Ferrara, ITALY; tel: e-mail: barbara.bramanti@unife.it
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Proceedings of the National Academy of Sciences