Bacteriologic Diagnosis 425 



placed by granular types when convalescence is established and just 

 before the throat is cleared of diphtheria-like bacilli. 



From these data the writers conclude that it is not safe to base 

 an opinion regarding the maintenance of quarantine upon the 

 bacterioscopic findings independently of the clinical history of the 

 case. 



The occurrence of true diphtheria bacilli in the throats of healthy 

 persons has been a stumbling-block to many practitioners unin- 

 formed upon bacteriologic subjects, who fail to account for its 

 presence and Ulso fail to realize how rare its appearance under such 

 circumstances really is. 



Park* found virulent diphtheria bacilli in about i per cent, of 

 the healthy throats examined in New York city, but diphtheria 

 was prevalent in the city at the time, and no doubt most of the 



01 



:Nv' 



d' 



f<.> 



4 





'^\ 



Fig. 158. — Wesbrook's types of Bacillus diphtheriae : a, c, i, Granular types; 

 a^, c', d^, barred types; o^, c^, d'^, solid types. X iS°°- 



persons in whose throats they existed had been in contact with 

 cases of diphtheria. He very properly concludes that the members 

 of a household in which a case of diphtheria exists, though they have 

 not the disease, should be regarded as possible sources of danger, 

 until cultures made from their throats show that the bacilli have 

 disappeared. 



Bacteriologic Diagnosis. — It is impossible to make an accu- 

 rate diagnosis of diphtheria without a bacteriologic examination. 



Such an examination is now within the power of every physician. 

 All that is required is a swab made by wrapping a little absorbent 

 cotton about the end of a piece of wire and carefully sterilizing it 

 in a test-tube, and a tube of Lofifler's blood-serum-medium, that can 



"Report on Bacteriological Investigations and Diagnosis of Diphtheria, 

 from May 4, 1893, to May 4, 1894." "Scientific Bulletin No. i," Health De- 

 partment, city of New York. 



