28 THE SMALLEST LIVING THINGS 



fever, tick fever, or bovine malaria. The cause of Texas fever is 

 not a spirochaete but another type of blood parasite called 

 Babesia bigemina and is related to the organism causing malaria 

 in man. The transmission was found to be due to a tick which 

 lives in the hair of cattle. 



In connection with spirochaete-transmission of disease two 

 physicians, Dr. Joseph Everett Dutton (1876-1905) of England 

 and Dr. John L. Todd (1876- ) of Canada, discovered in 



1903-1904, while on an expedition for the Liverpool School of 

 Medicine, the cause and mode of transmission of an African dis- 

 ease which the natives called tick fever. The spirochaete which 

 is responsible for this type of relapsing fever was named Trepo- 

 nema duttoni in honor of one of the discoverers who lost his life 

 during the investigation. It was found that the tick (Ornitho- 

 dorus moubata) abounds in old mattresses, clothing, etc., left 

 in the caravan camping sites and is ready to infect individuals 

 of the next caravan. It was also found that every organ of the 

 tick becomes penetrated with spirochaetes, whereas in man they 

 remain in the blood. The parasites may continue to live in the 

 tick for as long as eighteen months after a single infection. 



There is reason to believe that relapsing fever in Europe is 

 transmitted by human body-lice and head-lice. Bedbugs may 

 also be carriers of infection. It has long been known that un- 

 cleanliness, crowding, and close contact with infected persons 

 are characteristic conditions leading to the spread of the disease. 

 Relapsing fever has been produced in monkeys by inoculating 

 them with crushed infected lice. It is possible that in humans 

 the infection is transmitted when the fingers in scratching crush 

 infected lice. 



Yellow fever and infectious jaundice are spirochaete dis- 

 eases which are transmitted, not by ticks, but by mosquitoes, 

 and the history of the discovery of this relationship is the history 

 of heroes and martyrs to the glory of American medicine. Many 

 of us today remember when yellow fever frequently flared up 

 in epidemic form in our southern States, and many of us recall 

 the types of quarantine set up at such times. Express packages, 

 mail, laundry, etc., from a yellow-fever locality underwent sterili- 

 zation before delivery in another State. Today such precautions 

 are known to be without value and a needless expense. 



