2IO 



been able to isolate from the throat of recovered diphtheria 

 patients bacilli, which were very virulent to guinea-pigs even 

 after many months. 



So at the control-examination of convalescents the necessity 

 of extension of the routine work is only felt as an exception. 



Now I have come to the most difficult part of the diphtheria 

 examination, namely the searching for diphtheria bacilli in nose 

 or throat of healthy individuals. 



In recent years a material extending over many thousand 

 persons had to be examined in our laboratory in order te 

 to discover diphtheria-carriers. It is my experience that the 

 presence of bacilli in throat or nose, which we must consider 

 as diphtheria bacilli, does not occur to so alarming a degree as 

 some wanted to make us believe. It is not exceptional that we 

 find at a school-examination, extending over many a hundred 

 of children, only a few diphtheria-carriers. 



The search for diphtheria-carriers may often be very useful 

 and very well practicable. For instance this was the case with 

 an examination made last summer in a holiday-home (»Vacan- 

 tie-kolonie«). A case of clinically and bacteriologically true 

 diphtheria occurred there, while some other children had slight 

 alïections of the throat. Now here the search for carriers seemed 

 to be in the right place ; it only concerned a small number — 

 40 à 50 — the isolation of those individuals by whom the 

 result was positive, was easily practicable and the danger of 

 spreading the infection was very great. 



Now by this examination a number of slightly affected and 

 perfectly normal bacilli-carriers were actually found, that is to 

 say that they were diagnosed as positive by the quick method 

 used by us for the discovery of diphteria bacilli. Here also 

 the examination had to be made quickly, a too scrupulous 

 weighing again and again of the diagnosis would have rendered 

 the useful result very problematic and therefore we used in this 

 also case the ordinary investigation methods. In some cases 

 arbitrary chosen we finished the examination to the end and by 

 this was shown, that the isolated microorganisms were really 

 typical diphtheria bacilli virulent to guinea-pigs. 



Let us contrast to this example of a useful examination for 

 diphtheria-carriers an unuseful one. In a village there is much 



