Black Death

The bubonic plague mechanism was also dependent on two populations of rodents: one resistant to the disease, which act as hosts, keeping the disease endemic, and a second that lack resistance.

The bubonic plague mechanism was also dependent on two populations of rodents: one resistant to the disease, which act as hosts, keeping the disease endemic, and a second that lack resistance.

When the second population dies, the fleas move on to other hosts, including people, thus creating a human epidemic.

The historian Francis Aidan Gasquet wrote about the Great Pestilence in 1893 and suggested that "it would appear to be some form of the ordinary Eastern or bubonic plague".

He was able to adopt the epidemiology of the bubonic plague for the Black Death for the second edition in 1908, implicating rats and fleas in the process, and his interpretation was widely accepted for other ancient and medieval epidemics, such as the Plague of Justinian that was prevalent in the Eastern Roman Empire from 541 to 700 CE.

An estimate of the mortality rate for the modern bubonic plague, following the introduction of antibiotics, is 11%, although it may be higher in underdeveloped regions.

An estimate of the mortality rate for the modern bubonic plague, following the introduction of antibiotics, is 11%, although it may be higher in underdeveloped regions.

Symptoms of the disease include fever of 38 –, headaches, painful aching joints, nausea and vomiting, and a general feeling of malaise.

Symptoms of the disease include fever of 38 –, headaches, painful aching joints, nausea and vomiting, and a general feeling of malaise.

Symptoms of the disease include fever of 38 –, headaches, painful aching joints, nausea and vomiting, and a general feeling of malaise.

Symptoms include fever, cough, and blood-tinged sputum.

Symptoms are high fevers and purple skin patches (purpura due to disseminated intravascular coagulation).

Symptoms are high fevers and purple skin patches (purpura due to disseminated intravascular coagulation).

In October 2010, the open-access scientific journal PLOS Pathogens published a paper by a multinational team who undertook a new investigation into the role of Yersinia pestis in the Black Death following the disputed identification by Drancourt and Raoult in 1998.

They assessed the presence of DNA/RNA with polymerase chain reaction (PCR) techniques for ''Y.

They assessed the presence of DNA/RNA with polymerase chain reaction (PCR) techniques for ''Y.

pestis'' from the tooth sockets in human skeletons from mass graves in northern, central and southern Europe that were associated archaeologically with the Black Death and subsequent resurgences.

The authors concluded that this new research, together with prior analyses from the south of France and Germany, "ends the debate about the cause of the Black Death, and unambiguously demonstrates that Y. pestis was the causative agent of the epidemic plague that devastated Europe during the Middle Ages".

The study also found that there were two previously unknown but related clades (genetic branches) of the ''Y.

pestis'' genome associated with medieval mass graves.

pestis'' genotype responsible for the pandemic that spread through the Low Countries from 1350 differed from that found in Britain and France, implying Bergen op Zoom (and possibly other parts of the southern Netherlands) was not directly infected from England or France in 1349 and suggesting a second wave of plague, different from those in Britain and France, may have been carried to the Low Countries from Norway, the Hanseatic cities or another site.

pestis'' genotype responsible for the pandemic that spread through the Low Countries from 1350 differed from that found in Britain and France, implying Bergen op Zoom (and possibly other parts of the southern Netherlands) was not directly infected from England or France in 1349 and suggesting a second wave of plague, different from those in Britain and France, may have been carried to the Low Countries from Norway, the Hanseatic cities or another site.

pestis'' genotype responsible for the pandemic that spread through the Low Countries from 1350 differed from that found in Britain and France, implying Bergen op Zoom (and possibly other parts of the southern Netherlands) was not directly infected from England or France in 1349 and suggesting a second wave of plague, different from those in Britain and France, may have been carried to the Low Countries from Norway, the Hanseatic cities or another site.

A study published in Nature in October 2011 sequenced the genome of ''Y.

In 1984, zoologist Graham Twigg produced the first major work to challenge the bubonic plague theory directly, and his doubts about the identity of the Black Death have been taken up by a number of authors, including Samuel K. Cohn, Jr. (2002 and 2013), David Herlihy (1997), and Susan Scott and Christopher Duncan (2001).