THERAPEUTIC IMMUNIZATION IN MAN 503 



the treponemata in culture have convinced us that these micro- 

 organisms may assume for long periods a condition of metabolic 

 latency, a sort of resting period, during which they incite no reactions 

 of any kind on the part of the tissues, apparently do not multiply 

 to any great extent and yet remain alive and capable of development 

 when conditions favor this. 



In spite of these difficulties, however, careful clinical studies by 

 Jonathan Hutchinson, Taylor, Hudelo, 132 Neisser, and many others, 

 have furnished data which warrant an opinion upon this problem. 

 Of especial value is the painstaking analysis of reported cases of re- 

 infection in syphilis made in 1909 by Felix John. 133 



In contrast with some others who have attempted similar analyses 

 John takes the utmost care to separate these cases into the ones in 

 which the evidence of true reinfection is absolute, and those in which 

 the reported details are insufficient to exclude the possibility of 

 recrudescence. In agreement with Taylor he insists upon a symptom- 

 free interval of five years between the last manifestations of the 

 first attack and the appearance of the second. As an example of 

 what he calls an "Ideal Fall" we may cite the following: 



X. J., April 1, 1872, primary sore. 



Roseola, polyadenitis, mucous patches. September, 1872, papular rash. 

 March, 1873, palmar and plantar spots, iritis. 1875, gumma of tibia and 

 serpiginous syphilide of right thigh. 



Four courses of inunctions and KI. 



1876, married two healthy children. 



No symptoms till 1887 when he acquired a second chancre followed by 

 typical roseola. In 1888 wife had still-birth. 



John has analyzed in this way 356 cases of supposed reinfection, 

 in 34 of which the first attack was of congenital origin. Of the 

 remaining 322, fourteen were cases which seemed unquestionable 

 instances of reinfection and in 16 more there was practically no 

 doubt of this. Of the 34 hereditary cases there were three, one of 

 Emery, one of Taylor, and one of Hochsinger, in which there was 

 practically no question of their nature as valid reinfections. In all 

 of the others there was one point or another which rendered them 

 doubtful as evidence. 



John concludes that true reinfection can unquestionably occur 

 in syphilis but that it is relatively rare. 



To John's cases Neisser has added others reported between 1909 

 and 1911. Yet even with these, the total number is not a large one. 

 Nevertheless, we should not be tempted to conclude from this that 

 the relative infrequency of such cases is evidence in favor of the 



132 Hudelo. Ann. de dermat. et de syph., 1890, 353. 



133 John, Felix. Eeinfectio Syphilitica, Samml. klin. Vortr., Volkmann, 

 1907-1909, 559 et seq. 



