450 MALTA FEVER 



position, the officers, for example, suffering more in proportion 

 than the privates. Another interesting fact, pointed out by 

 Horrocks, is that the disease has practically disappeared from 

 Gibraltar since the practice of importing goats from Malta has 

 stopped. 



The work of the Commission, so far as it has gone, has 

 been to exclude other modes of infection as being of practical 

 importance, by dust, by the bites of mosquitoes, etc., and if it 

 is conveyed by contact at all, this is only when the contact is 

 of an intimate character, and even then it is probably of rare 

 occurrence. Although numerous patients suffering from the 

 disease come to England, there is no known case of fresh 

 infection arising under natural conditions. 



Agglutinative Action of Serum. The blood serum of patients 

 suffering from Malta fever possesses the power of agglutinating 

 the micrococcus melitensis in a manner analogous to what has 

 been described in the case of typhoid fever. The reaction 

 appears comparatively early, often about the fifth day, and may 

 be present for a considerable time after recovery sometimes 

 for more than a year. Distinct agglutination with a 1 : 20 

 dilution of the serum in half an hour may be taken as a positive 

 reaction, sufficient for diagnosis. The reaction is, however, 

 usually given by much higher dilutions, e.g. 1 : 500, and even 

 higher. It is to be noted that normal serum diluted 1 : 2 may 

 produce some agglutination. As regards relation to prognosis, 

 the observations of Birt and Lamb and of Bassett-Smith have 

 given results analogous to those obtained in typhoid (p. 340). 



The Commission has recently found that vaccination with 

 dead cultures of the micrococcus confers a certain degree of 

 protection amongst those exposed to the disease. As a rule two 

 injections were made, 200-300 million cocci being the dose of 

 the first injection, and about 400 million of the second. The 

 use of vaccines has also been carried out in the treatment of 

 the disease, but the observations are not sufficiently numerous 

 to allow a definite statement to be made as to its value. 



Methods of Diagnosis. During life the readiest means of 

 diagnosis is supplied by the agglutinative test just described 

 (for technique, vide p. 109). 



Cultures are most easily obtained from the spleen either 

 during life or j>o*t mortem. Inoculate a number of agar tubes 

 by successive strokes and incubate at 37 C. Film preparations 

 should also be made from the spleen pulp and stained with 

 carbol-thionin-blue or diluted carbol-fuchsin (1 : 10). 



