442 Diphtheria 



diphtheria bacillus, when grown upon blood-serum, is short and 

 stains uniformly; that cultures grown in bouillon develop more 

 rapidly at a temperature of from 20° to 2 2°C. than those of the 

 true bacillus; and that the pseudo-bacillus is not pathogenic for 

 animals. 



Contagion. — The diphtheria bacilli, being always present in the 

 throats of patients suffering from diphtheria, constitute the element 

 of contagion. 



The results obtained by Biggs, Park, and Beebe in New York 

 are of great interest. Bacteriologic examinations conducted in 

 connection with the Health Department of New York City show 

 that virulent diphtheria bacUli may be found in the throats of 

 convalescents from diphtheria as long as five weeks after the dis- 

 charge of the membrane and the commencement of recovery, and 

 that they exist not only in the throats of the patients themselves, 

 but also in those of their caretakers, who, while not themselves 

 infected, may be the means of conveying the disease germs from 

 the sick-room to the outer world. Still more extraordinary are the 

 observations of Hewlett and Nolen,* that the bacilli remained in 

 the throats of patients seven, nine, and in one case twenty-three 

 weeks after convalescence. The hygienic importance of this ob- 

 servation must be apparent to all readers, and serves as further 

 evidence why thorough isolation should be practised during conva- 

 lescence and after it so long as the patient can be shown to be a 

 "carrier" of the infectious agents. 



Neumann t found that virulent diphtheria bacilli may occur in 

 the nose with the production of what seems to be a simple rhinitis 

 as well as a pseudo-membranous rhinitis. Such cases, not being 

 segregated, may easily serve to spread the contagion of the disease. 



The occasional occurrence of true di{)htheria bacilli in the throat 

 of healthy persons who have been exposed to diphtheria, has been a 

 stumbling-block to many practitioners uninformed upon bacterio- 

 logic subjects, who are unable to account for its presence, fail to 

 realize how rare its appearance under such circumstances really is, 

 and hesitate to concede that persons so harboring it are "carriers" 

 and may spread infection. 



Parkt 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 

 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, 



* "Brit. Med. Jour.," Feb. i, 1896. 



t "Centralbl. f. Bakt. u. Parasitenk.," Jan. 25, igo2, Bd. xxxi, No. 2, p. 41. 



t "Report on Bacteriologicallnvestigations and Diagnosis of Diphtheria, from 

 May 4, 1893, to May 4, 1894." "Scientific Bulletin No. i," Health Department, 

 City of New York. 



