140 MALTA FEVER 



low power appear much like minute drops of water. It is destroyed 

 by moist heat in about five minutes at 60 C. (140 F.), with dry heat 

 at 95 C. (203 F.) and by direct sunlight within from a few minutes 

 to an hour depending on the thickness of the layer and the intensity 

 of the light. It is quite highly susceptible to the usually employed 

 chemical disinfectants. However, in old cultures kept in the dark it 

 may retain its vitality for more than a year, especially when complete 

 desiccation is prevented by a rubber cap. In laboratory animals both 

 acute and chronic infections can be induced. For the production of 

 the former a relatively large inoculation is necessary. The weight 

 begins to fall in a few hours, then the temperature falls and rises. The 

 animal becomes weaker, develops general tonic convulsions and at last 

 falls into coma with low temperature, and dies. Necropsy shows a 

 general septicemia with frequent acute inflammation of the mucous 

 membrane of the urinary organs. 



The chronic form, after an incubation of from two to three days 

 develops a remittent or intermittent low fever with slow progressive 

 emaciation. For months the animal may seem quite well, save for the 

 slow, continued wasting, when it dies suddenly. After death most of 

 the organs are found to be sterile, but usually the coccus in small 

 numbers will be found in the bone marrow or the kidneys, or in both. 

 Usually it is abundant in the urine during the whole course of the 

 disease. The spleen is generally found to be markedly enlarged, like- 

 wise some of the lymphatic glands. 



Horses, donkeys, cattle, sheep and goats are susceptible to inocu- 

 lation. The study of this infection in goats is of special interest. In 

 these animals the disease is exceedingly chronic and seems to disturb 

 the animal but little. The temperature is not altered and there is not 

 always a decrease in weight. Frequently there is a dry cough. From 

 the end of the first to that of the third week the blood serum of the 

 animal promptly agglutinates the micrococcus. Indeed, this is the only 

 way in which Malta fever can be positively diagnosed in either man or 

 animals. In 1906 an English commission found one-third of the goats 

 on the island of Malta infected with this disease and the micro- 

 organism in the milk of one-tenth. The question of how the goats 

 become infected naturally is an interesting one. Experimentally this 

 is easily done through an abrasion and it is supposed that naturally 



