128 TROPICAL MEDICINE AND HYGIENE 



many problems are involved. It is not proposed to give 

 an exhaustive history of the occurrence of the disease. 

 Till recently there has been so much confusion between 

 yellow fever and malaria, particularly the clinical variety 

 of it known in the West Indies as bilious remittent fever, 

 subtertian malaria, and possibly Weil's disease, that many 

 of the records are of doubtful value. A fatal fever was 

 first recorded in San Domingo amongst the followers of 

 Columbus in 1493, fourteen months after the discovery 

 of America, and ten years before the first shipment of 

 slaves to America. This outbreak, if, as seems probable, 

 it was yellow fever, would prove that the disease was 

 one of the New World and not of African importation. 



Though various outbreaks occurred in some of the 

 West Indies in the sixteenth and seventeenth centuries, it 

 was not till the big outbreak which swept all through the 

 West Indies and to South America in 1793 that it be- 

 came of general occurrence, and in each island or country 

 it appears to have been considered as a new disease. 

 Since then outbreaks have occurred in most places every 

 twelve to twenty years on the average. 



In West Africa and the West African islands the 

 disease, or a similar fatal fever, was early noted, the first 

 outbreak being in 1510, though there had been an epi- 

 demic in the Canaries in 1494. In West Africa, the 

 Canaries, and Madeira there were outbreaks every twelve 

 years in the sixteenth century, three times in the seven- 

 teenth, ten times in the eighteenth, and eleven times in 

 the nineteenth century. 



The intervals when places were believed to be free 

 varied from short intervals of one to five years, to longer 

 ones twenty, fifty, or in one instance sixty years. 



In Bermuda the first record of an epidemic is in 1699, 

 but since then there have been frequent outbreaks, some 

 local and some widespread. 



Several authorities, including Blair, point out that great 

 variations in the severity and characters of epidemics 

 occur. And Blair in his description of the disease divides 



