MALTA FEVER, SLEEPING SICKNESS, ETC. 403 



the spleen of patients dead of the disease an organism now known as the Micrococcus 

 melitensis. Clinically, Malta fever is a disease of long duration and variable 

 symptoms, including remitting fever. Perspiration, pains, swelling of joints, en- 

 largement of the spleen, etc., are among the common signs. Micrococcus melitensis 

 is a small, round, or slightly oval coccus, singly, in pairs, or chains. Does not stain 

 by Gram's method. Can be cultivated on agar at 37 C. from the spleen ; colonies 

 appear about third day as small, round, slightly raised growths, old cultures assume 

 a buff tint. Addition of nutrose hastens growth of culture. On gelatine growth is 

 very slow ; there is no liquefaction. In broth there is a turbid growth, without 

 pellicle formation. 



Cultures kept at 22 C. retain their vitality for fourteen months, but the organism 

 dies in about five days in sterile, fresh, and sea water and urine, but remains active 

 for longer in sterile milk, and for sixty-nine days in dust. The organism is present 

 in the peripheral blood in all cases during the early stages, and in severe pyrexial 

 relapses. It has recently been isolated from the urine of patients. The disease 

 appears to be inoculable in animals. 



Sleeping Sickness. Investigations point to the conclusion that sleeping sickness 

 is caused by the entrance into" the blood, and thence into the cerebro-spinal fluid, of 

 a species of trypanosoma (probably the Trypanosoma gambiene, discovered by Forde 

 and described by Button), which is transmitted from the sick to the healthy by a 

 species of tsetse fly (Olossina palpalis), and by it alone ; that, in short, sleeping 

 sickness is a human tsetse-fly disease. From a series of carefully controlled and 

 minutely observed experiments, carried out by Bruce, Nabarro, and Grieg, it was 

 discovered that monkeys inoculated with cerebro-spinal fluid from sleeping sickness 

 patients, or with blood from natives not as yet showing symptoms of sleeping sick- 

 ness, but containing a similar parasite, sickened and died with all the symptoms of 

 sleeping sickness. 



From the analogy of the closely related disease in cattle, the nagana or tsetse fly 

 disease of South Africa, it was suspected that in sleeping sickness a like method of 

 infection took place. It has been demonstrated by experiment that not only were 

 these flies, fed on sleeping sickness cases, capable of conveying the disease to healthy 

 monkeys, but that the freshly caught flies from an infected area, without any arti- 

 ficial feeding, were also capable of conveying the disease. 



It was further discovered by a carefully-organised investigation that this fly, like 

 its congener the tsetse fly of South Africa, is confined to well-defined areas, and that 

 these areas correspond absolutely with the distribution of sleeping sickness ; whereas, 

 in regions where no Glossina palpalis is found, although other biting flies abound, 

 there is no sleeping sickness. Moreover, an examination of a large number of 

 individuals in the sleeping sickness areas and the non-sleeping sickness areas 

 respectively, revealed the fact that, while a large percentage (28) of the inhabitants of 

 the sleeping sickness areas have in their blood the trypanosoma already referred to, 

 in not a single case taken from inhabitants of non-sleeping sickness areas was this 

 parasite found." The only other human trypanosome at present known is that 

 occurring in trypanosomiasis. 



Dysentery is another tropical disease in which the etiology has not been finally 

 worked out. Endemic or tropical dysentery is possibly due to Amoeba coli. Epi- 

 demic dysentery is more probably due to Bacillus dysenteric, and sporadic and 

 parasitic dysentery is due to various parasites, such as Balantidium coli and the 

 Bilharzia. B. dysenteries is a short rod, often occurring in pairs ; non-motile ; does not 

 stain by Gram's method ; does not curdle milk nor liquefy gelatine, f The researches 



* See also Brit. Med. Jour., 1903, vol. i., p. 1431; and vol. ii., pp. 1343 and 

 1427 ; and Lancet, 1904 (July), p. 290, for a resume. 



f For a full discussion of the subject, see Brit. Med. Jour., 1901, vol. ii., p. 786, 

 "A Comparative Study of the Bacilli of Dysentery"; and 1903, vol. i., p. 1315, 

 " Amoebic Dysentery in India " ; and Report of Royal Commission on Dysentery, 

 1903. For description of B. dysenteries, see Report of Medical Officer to Local Govt. 

 Bd., 1901-02, p. 396; Brit. Med. Jour., 1904, vol. i., p. 1002; Edin. Med. Jour. 

 (June), 1904, p. 489 (Eyre). 



