SPECIAL BACTERIOLOGY 
169 
resist drying for several weeks. Chemical disinfectants 
easily destroy the organism. 
V. Disease Production, Mode of Infection and 
Prophylaxis 
Diphtheria is usually confined to the throat, larynx, 
and nose, but it may attack other mucous membranes for 
which the bacillus seems to have a special predilection. 
Diphtheria is transmitted by coming in contact with 
those suffering with disease. For this reason all such 
persons should immediately receive an injection of diph¬ 
theria antitoxin; the patient should be isolated, quaran¬ 
tined, and the strictest precautions should be taken in 
Fig. 32.—One of the very characteristic forms of diphtheria bacilli from 
blood-serum cultures, showing clubbed ends and irregular stain. x 11UU 
diameters. Stain, methylene blue. (Park and Williams Pathogenic Bac¬ 
teria and Protozoa .) 
disinfecting his or her utensils, linen, etc. Severe 
epidemics are frequent, usually in institutions, such as 
schools, asylums, etc. 
A very important question today is that of diphtheria 
bacilli carriers. It is known that many persons may har¬ 
bor the diphtheria bacilli in their throats and yet show 
no signs of the disease; in spite of this, however, they 
are always a source of danger to others; and therefore, 
