438 RELAPSING FEVER AND AFRICAN TICK FEVER 



subcutaneous inoculation. In many cases a diagnosis may be 

 made by microscopic examination alone, as in no other known 

 condition than plague do bacilli with the morphological char- 

 acters of the plague bacillus occur in large numbers in the lym- 

 phatic glands. The organism may be obtained in culture from 

 the blood in a considerable proportion of cases by withdrawing 

 a few cubic centimetres and proceeding in the usual manner. 

 On the occurrence of the first suspected case, every care to 

 exclude possibility of doubt should be used before a positive 

 opinion is given. 



In a case of suspected plague pneumonia, in addition to 

 microscopic examination of the sputum, the above cultural 

 methods along with animal inoculation with the sputum should 

 be carried out ; subcutaneous injection in the guinea-pig and 

 smearing the nasal mucous membrane of the rat may be recom- 

 mended. Here a positive diagnosis should not be attempted by 

 microscopic examination alone, especially in a plague-free dis- 

 trict, as bacilli morphologically resembling the plague organism 

 may occur in the sputum in other conditions. 



RELAPSING FEVER AND AFRICAN TICK FEVER. 



At a comparatively early date, namely in 1873, when practi- 

 cally nothing was known with regard to the production of disease 

 by bacteria, a highly characteristic organism was discovered in 

 the blood of patients suffering from relapsing fever. This 

 discovery was made by Obermeier, and the organism is usually 

 known as the spirillum or spirochoete Obermeieri, or the spirillum 

 of relapsing fever. He described its microscopical characters, 

 and found that its presence in the blood had a definite relation 

 to the time of the fever, as the organism rapidly disappeared 

 about the time of the crisis, and reappeared when a relapse 

 occurred. He failed to find such an organism in any other 

 disease. His observations were fully confirmed, and his views 

 as to its causal relationship to the disease were generally accepted. 

 Later, the disease was produced in the human subject by inocula- 

 tions with blood containing the organisms, and a similar con- 

 dition has been produced in apes. 



Recently it has been shown that the so-called "tick fever" 

 prevalent in Africa is also due to a spirochaete of similar 

 character, and results of the highest importance have been 

 established with regard to the part played by ticks in the trans- 

 mission of the disease. Doubt still obtains as to the relationship 

 of the organisms of the two diseases, but all are agreed that they 



