MEASLES 563 



The milk of infected cows contains the virus, and the disease is 

 transmissible to man, particularly young children, through raw or 

 imperfectly pasteurized milk, and possibly from butter and cheese 

 made from infected milk. The disease is mild, as a rule, in older 

 children, but it may be severe or fatal for infants. 



The virus belongs to the group of filterable viruses and, in its purest 

 state, is found in the contents of the vesicles. Early in the disease the 

 virus also circulates in the blood stream. Loffler and Frosch, 1 who 

 discovered the filterable nature of the virus, found that the vesicular 

 fluid, filtered through unglazed porcelain filters, retained its infectious- 

 ness for some time, provided the fluid be kept cool and in the dark. 



Contagious Pleuropneumonia of Cattle. This disease was the first 

 to be described in which the virus passes through unglazed porcelain 

 filters, although the filtration of the virus was not attempted at thaf 

 time. Xocard and Roux 2 examined the exudate from the lungs of 

 diseased cattle microscopically with negative results. They suspended 

 it in broth, enclosed in collodion capsules, in the peritoneal cavities 

 of guinea-pigs. After two to four weeks the medium became turbid, 

 while controls remained clear. Examination of the fluid under a 

 magnification of 2000 diameters revealed very minute, highly refrac- 

 tile spots which exhibited Brownian movement. They claim to have 

 cultivated the virus in a peptone-serum medium and to have obtained 

 minute colonies (0.5 mm. diameter) on peptone-serum agar. Later 

 the virus was shown to pass through Berkefeld filters and the coarser 

 grades of porcelain filters, but not the finer grades. 



The disease is confined to cattle; man is immune so far as is known. 



DISEASES OF UNKNOWN ETIOLOGY. 



Measles. The etiology of measles is unknown, but Hektoen 3 

 produced the disease in two susceptible individuals by injecting 

 blood from a patient exhibiting typical symptoms. The blood was 

 removed about thirty hours after the appearance of the eruption, and 

 the disease induced was clinically perfectly typical. Anderson and 

 Goldberger 4 report a successful inoculation of several monkeys with 

 blood from human cases; four out of a total of nine animals developed 

 a febrile reaction and a limited eruption. The virus was carried 

 through three monkey generations in one experiment. Growth was 



1 Central bl. f. Bakt., I Abt., 1898, xxiii, 371. 2 Ann. Inst. Past., 1898, xii, 240. 



3 Jour. Inf. Dis., 1905, ii, 238. < Public Health Rep., 1911, xxvi, No. 24. 



