the black death in early ottoman territories - Bilkent University

CHAPTER II
A BIOLOGICAL AND HISTORICAL VIEW OF PLAGUE
2.1. Modern Concepts of Plague
In order to evaluate the sociological impact of the plague outbreaks on
medieval society, it is important to have a basic knowledge of the epidemiology
and ethiology of plague. Different clinical manifestations of the disease caused by
the bacteria Yersinia pestis are known: bubonic plague, characterized by the
appearance of buboes or swellings of the lymph nodes 8 , septicaemic plague 9 or an
overwhelming infection of the bloodstream and primary pneumonic plague,
resulting in pneumonia. 10 The latter form is the most fulminant and fatal form of
plague. It is also the type that spreads readily from one human to another through
droplet infection by coughing. Epidemics in man usually involve the bubonic
form of the disease for which the incubation period is 2 to 5 days, but there is
always a small number of patients with primary septicaemic plague. The mortality
rate among patients that are not treated with antibiotics ranges from 60 % to 90 %.
8 Buboes can become as big as an orange and develop especially in the armpits, neck and groins.
9 In septicaemic plague, the plague bacteria are massively present in the patient's blood. This form
has a very acute course with the patient often dying in a matter of hours without developing other
symptoms. As with the bubonic form septicaemic plague is insect-borne, but in view of its
increased presence in the blood, it is yet more transmissible by fleas -see Hirst, L. Fabian. The
Conquest of Plague: A Study of the Evolution of Epidemiology. Oxford: Clarendon Press, 1953, 29.
10 For unknown reasons, some bubonic patients can develop secondary pneumonic symptoms,
making them directly contagious and creating an epidemic of air-borne primary pneumonic plague.
(Hirst, The Conquest of Plague, 30). Moreover, Hirst lists other types of plague, such as the
cellulo-cutaneous or carbuncular version, where skin lesions are formed, the tonsillar or anginal
form and the vesicular type. The vesicular form is characterized by pustules, called blains in the
sources, that are reminiscent of smallpox. The dark-coloured tokens appearing on the skin of
patients were yet another symptom of cellulo-cutaneous plague.
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