364 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Dr. A. p. ITitclieiis (American Veterinary Review, Vol. XXXVTI, 

 p. 597), who carried out similar experiments on horses, failed to notice 

 the de^■clopment of any symptoms of the disease in the animals receiv- 

 ing more than 100 units. AVhile the neutralization of the developing 

 toxin may take place from such small quantities of antitoxin if 

 injeojted early enough after the infection, it might not be entirely 

 safe to use such a small dosage of antitoxin when it is injected after a 

 longer period than one day following the infection. 



From the results of these two investigations it may therefore be 

 concluded that 500 American units is a sullicient dose of antitoxin 

 for use as a prophylactic, even in cases where the infection has 

 occurred four days prior to the injection of the antitoxin. 



MALTA FEVEK. 



By the recent investigations of Gentry and Ferenbaugh, of the 

 Medical Corps, United States Army, the existence of malta fever in 

 Texas has been definitely established. Its occurrence in human beings 

 has been demonstrated bacteriologically among certain families in the 

 goat-raising sections of Texas, and since goats have been incrimi- 

 nated as carriers of the infection to man, the sera of a number of 

 these animals in the infected localities were subjected to the aggluti- 

 nation test with positive results. The isolation of the Micrococcus 

 melitensis from these goats was not successful, and the agglutination 

 test was therefore relied upon for the diagnosis of malta faver in 

 these animals. The occurrence of the disease in Texas has been 

 substantiated by Mohler and Eichhorn, of this bureau, who obtained 

 positive results not only with the agglutination test, but also with 

 the complement-fixation test of sera from goats sent to the laboratories 

 at "Washington from the infected localities of Texas and New Mexico. 



The existence of this disease in Texas and New Mexico is of great 

 moment, inasmuch as the general opinion has prevailed that the 

 United States is free of malta fever, and that the only occasions when 

 the disease has appeared in this counti*y were isolated instances oc- 

 curring through importation. However, from a careful investiga- 

 tion in the infected districts it seems evident that malta fever, which 

 is also known locally as mountain fever and slow typhoid fever, has 

 existed in Texas and New Mexico for at least 25 years; that the dis- 

 ease has always made its appearance among people connected with 

 goat raising; that entire families have been taken sick with the dis- 

 ease on goat ranches; that many of the goat ranches have had one 

 or more cases of the fever among the people connected with them; 

 and that in some years there are numerous cases of the disease, while 

 in other years only a few cases will appear. The affection appears 

 usually after the kidding season, during the months of April, May, 

 and June, when the people are in closer contact with the goats. It 

 is stated that the Mexican goat herders are quite infrequently affected, 

 but this may be due not to any natural immunity but to the fact that 

 the Mexicans ahvaj^s boil the milk before drinking it, while the 

 Americans use the milk raw. The origin of the disease in that 

 section is indefinite, but it is claimed that the affection prevailed in 

 Texas when the common goat was the only goat in the country and 

 long before any of the fancy breeds of goats were imported from 

 South Africa, where malta fever has been found to exist. 



