278 THE INFECTIOUS DISEASES. 



which it entails to the incursions of pathogenic germs other than that 

 which we believe to be its excitant. Thus an infectious croupous in- 

 flammation of the mouth, tonsils, pharynx, larynx, and trachea, due to a 

 streptococcus (see page 209), is a frequent complication. True diph- 

 theria due to the Loffler bacillus is also prone to establish itself upon the 

 vulnerable inflamed mucous membranes. So also the frequently asso- 

 ciated pneumonia, the inflammatory hyperplasia and suppuration of the 

 lymph -nodes, suppurations in various parts of thel>ody, the endocarditis 

 and pericarditis which are not uncommon, may all be due to a secondary 

 infection with the pyogenic cocci. * 



MEASLES. 



A readily communicable infectious disease, the most prominent feat- 

 jires^of which are an intense hypersemia with inflammation of the ski% 

 associated with catarrhal infljyniaaiion of the mucous membrane of the 

 air passages. The inflammation of the skin isjinatomically of the same 

 general type asjbhat in scarlatina, Albuminous degeneration of the kid_- 

 ney^ or acute_exudatiye nephritis may occur. FocaJ necroses, in the liver 

 and kidneys have been described by Freeman. 4 



The more common secondary lesions are broncho - pneumonia^ pseudp- 

 membranous inflg.Tnma.ti 91^ of the pharynx and larynx, suppuratiye in- 

 flammation in various parts of the bodyTand diphtheria. These compli- 

 rations^ as in scarlatina, are doubtless, in part at least, dii-to secondary 

 infection with other germs than those causing the disease itself. 



The ^xcit^nt of measles is not definitely known. 



Canon and Pielicke in 1892 3 recorded the discovery in the blood in fourteen cases 

 of measles of very small bacilli, about as long as the radius of a red blood cell, 

 but varying considerably in size. These bacilli were sometimes abundant, sometimes 

 scanty in the blood, lying singly or in heaps. Meagre cultures were obtained in three 

 cases in beef tea. They did not seem to grow on the ordinary solid media. Bacilli 

 similar in form were found in the exudate from inflamed mucous membranes in measles. 

 The observations of these writers are interesting and suggestive, but until they shall 

 have been confirmed by others and greatly extended nothing can be assumed as estab- 

 lished regarding the etiological significance of the germs. 



WHOOPING-COUGH. (Pertussis.) 



Whooping- Cough is an infectious disease, often epidemic, without 

 characteristic lesions. There may be an associated bronchitis or bron- 

 cho-pneumonia. Several observers have isolated bacilli from the sputum 

 in whooping-cough many of them closely resemble the influenza bacillus 

 in form and culture but the proof that these are the excitants of the 

 disease has not been furnished. 4 



1 Consult for a study and bibliography Pearce, " Scarlet Fever, its Bacteriology and 

 Gross and Minute Anatomy," Med. and Surg. Reports of the Boston City Hospital, 

 1898 and 1899 ; also Weaver, American Medicine, April 18th, 1903. 



2 Freeman, Arch, of Pediatrics, February, 1900. 



3 Berliner klin. Wochenschr., April 18th, 1892. 



*Koplik; Centralblatt flir Bakteriologie, etc., Abth. I., Bd. xxii., p. 222, 1897; 

 Walnh, "Contributions from the William Pepper Laboratory of Clinical Medicine," 1900, 

 p. 450, bibl. ; Jochmann, Zeitschr. f. Hygiene u. Infkr., Bd. xliv., 1903, p. 498, bibl. 



