THE RELAPSING FEVERS OF AMERICA 



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THE RELAPSING FEVERS OF AMERICA. 



The relapsing fevers of America comprise: — 



1. North American relapsing fever. 



2. Central American relapsing fever. 



3. South American relapsing fever. 



I. Relapsing Fever of North America. 



Definition. — An acute specific fever caused by Spiroschaudinnia 

 novyi Schellach, 1907. Mode of infection not known. 



History. — Relapsing fever has been known in America for many 

 years, being recognized as far back as 1844; but it was considered 

 to be identical with the European type until, in 1906, an Englishman 

 who repeatedly travelled between New York and the West Indies 

 was treated by Carlisle in New York for fever which relapsed, and 

 in which spirochsetes were found. Novy and Knapp studied these 

 spirochaetes, and showed that they were distinct from S. duttoni. 

 Later, Mackie also studied them by the agglutination method, and 

 agreed with Novy, who had concluded, from morphological reasons, 

 that they were distinct from S. carteri. Finally, in 1907, Manteufel 

 compared them with true S. recurrentis, and found that the serum 

 of a person suffering from their type of fever did not agglutinate 

 true S. recurrentis. Subsequently Schellach, after studying and 

 comparing the different spirochaetes, named this particular species 

 S. novyi Schellach, 1907. 



Climatology. — ^The disease is known in North America and in 

 Europe. In America the disease is acquired naturally. In Europe 

 the cases recorded are due to laboratory infection. 



-ffitiology. — -The cause of the disease is 5. novyi Schellach, 1907. 



Symptomatology. — ^The symptoms appear to be much the same 

 as in the European type of fever. The incubation period seems to 

 be at least five to seven days in duration, though cases have been 

 recorded in which symptoms developed almost immediately after 

 exposure to infection. In experimental cases it varied between 

 six and eight days. The duration of the first attack is about five 

 to six days, and it often begins with rigors; the tongue is moist, 

 except in grave cases, and the jaundice is mild, except in severe 

 cases; but the vomiting of bile is not uncommon, while diarrhoea is 

 only moderate in amount. Tympanites, hiccough, and haemor- 

 rhages from the nose, stomach, and bowels, as well as the kidney, 

 may be present in severe cases. The apyrexial interval is usually 

 seven to ten days, and is followed by the relapse, which is not 

 uncommonly absent. Usually there is only one relapse, and more 

 rarely two to five relapses. 



Mortality. — ^The mortality is not high, varying between 2 and 

 6 per cent. 



Treatment. — ^The treatment is the same as in the European type. 



