244 The Philippine Journal of Science 1923 



Untreated cases. —It is noteworthy that many failures fol- 

 lowed the inoculation of scrapings from a yaw in patients dur- 

 ing the secondary stage of the disease. This suggests that the 

 secondary granulomata do not arise readily from accidental 

 transference by the patient to abrasions in various parts of the 

 body. Reinoculation during the primary stage of the disease 

 might give a high percentage of "takes;" the results in the 

 secondary stage are of more interest. The failures we obtained 

 are in marked contrast to the results recorded by Charlouis. 

 This observer in 1881 carried out a large series of a variety of 

 human inoculations of fundamental interest and significance. 

 The records are given with such brevity, however, that no analy- 

 sis of the data is possible. Of four patients who were reinocu- 

 lated, three developed papillomata. On reinoculating two of 

 these patients, one was positive. Jeanselme and Angier(5) 

 reinoculated a fully developed yaws patient four months after 

 the onset and, again, five months later. The results were 

 negative. 



In our work, reinoculation in the late granulomatous stage 

 resulted only once in the development of a lesion. The most 

 striking characteristic of the experiment was the prompt spon- 

 taneous regression of the lesion. This seems to us to indicate 

 that a definite though not complete resistance to reinoculation 

 develops during a long-standing infection. 



Charlouis also inoculated ten individuals who had recovered 

 from yaws. In seven the result was positive, the disease run- 

 ning virtually the same course as in normal individuals who 

 were experimentally infected. It is obviously impossible to 

 state whether these individuals were actually cured of their 

 infection or were merely in a latent stage, and the number 

 of years that had elapsed since the onset of the disease is not 

 known. 



Treated cases.— The small group of yaws patients that were 

 reinoculated after treatment with neosalvarsan permits some 

 interesting observations. Only one of four cases developed a 

 typical, actively growing granuloma, and this patient had been 

 infected for only three months, the mother yaw being present 

 as well as secondary lesions at the time treatment with neosal- 

 varsan was started. Obviously this period of infection was 

 inadequate to establish any protection against the somewhat 

 severe test of experimental inoculation. One of the other 

 patients had been infected eight months, the mother yaw also 

 being present at the time the injections of neosalvarsan were 



