PLAGUE AND BACILLUS PESTIS 815 



has been mentioned in the introduction. Through the Middle Ages 

 a number of plague epidemics swept through Europe and frequently 

 reached the commercial ports of Italy, Asia Minor and other parts 

 of Eastern Europe from the Orient. In India it has long been 

 known as a fatal form of epidemic disease and since the early part 

 of the nineteenth century, has probably been endemic there. Cas- 

 tellani and Chalmers 15 state that it was introduced into China prob- 

 ably in the first half of the eighteenth century by Mohammedans 

 returning from Mecca via Burma to the Province of Yunnan. Here 

 it has been epidemic ever since. In 1894 the study of the Hongkong 

 epidemic revealed the causative agent of the disease. There was 

 a very serious epidemic in 1894 which started in China, spread 

 through Bombay to other parts of India, thence to Madagascar, 

 into the Malay States, the Philippine Islands, other islands of the 

 Pacific, reaching North and South America and Europe; finally 

 in 1900, it appeared in Cape Town and on the British Isles. Clemow, 

 whom we quote from Castellani and Chalmers, stated that in 1900 

 plague was 'endemic in Mongolia, Southern China, the Himalayas, 

 Mesopotamia, Persia, Uganda, parts of Russia and Northern Africa. 

 In Africa the same author states that there are two endemic areas, 

 one in Tripoli and the other in Uganda from which occasional 

 African epidemics take origin. 



The disease is, thus, a constant menace in many different parts 

 of the world and must remain an important source of concern to 

 national public health organizations. In the United States the 

 problem is perhaps more important than is appreciated by the people 

 at large. In 1903 the disease appeared in California and for several 

 years after that human cases occurred, though the disease never 

 took on the menace of an epidemic. This was prevented probably 

 by the energetic work of the United States Public Health Service 

 under Rupert Blue, McCoy, 16 Curry, and Wherry 17 who instituted 

 energetic methods of rat extermination, rat proofing and other neces- 

 sary sanitary measures. More recently, foci have appeared in Texas 

 and Now Orleans and it must never be forgotten that the conditions 

 of climate and in other respects are not by any means unfavor- 

 able to the development and spread of plague in some parts of 

 America. 



To convey an idea of the prevalence of plague in the world to-day 



16 McCoy, Pub. Health Report., July, 1913, No. 37. 



17 Wherry, Jour. Infec. Dis., 5, 1908. 



