xiv ORIENTAL PLAGUE 



view, could befall a community than an epidemic outbreak 

 of bubonic plague in a large and crowded city. An 

 epidemic might originate from a patient or patients who, 

 while not exhibiting symptoms clinically typical of plague, 

 nevertheless harbour the B. pestis, and this being over- 

 looked might become a focus of further infection. If such 

 be the case, the blame that an important step in the 

 diagnosis of the disease, namely, the bacteriological evi- 

 dence, had been omitted would rightly fall on those who 

 relied solely on clinical evidence. The bacteriological 

 examination of cases which, for one reason or another, 

 are under suspicion of being affected with plague, and 

 if undetected may be the means of introducing the 

 disease into a new locality, is therefore of the greatest 

 importance, since the clinician cannot venture to pro- 

 nounce on the case with certainty. The same applies to 

 rats in a ship coming from a plague -infected locality. 

 It is established that ships have harboured plague rats 

 without any one on board contracting the disease, but 

 nevertheless such a ship if left to itself remains a real 

 source of danger, not only to those who afterwards use 

 it — as has actually occurred — but to the port of landing, 

 where its plague-sick rats may carry infection to rats on 

 shore, and further carry infection to human beings. The 

 bacteriological diagnosis of plague in rats — the only ex- 

 amination that is of scientific value — is from a public 

 health point not less important than the examination of 

 suspected human cases. 



In the following pages we shall have opportunity of 

 giving an account of cases which, from a clinician's and 

 epidemiologist's point of view, were under suspicion of 

 being plague, and on bacteriological analyses were 



