206 



shown by experiment to transmit the disease. Ovine piroplas- 

 mosis is convej-ed by Rhipicephalus bursa, and the canine disease 

 is transmitted by Rh. sanguineus in the northern hemisphere, 

 though in South Africa Haemaphysalis leachi is the vector. 



The only drug which exerts an influence on some of these 

 parasites is trypan-blue, a dye which is administered intra- 

 venously, in preference to subcutaneously, in 1-1^ per cent, 

 aqueous solution. A dose of 5-10 cc. is curative for dogs, and the 

 drug is being used to-day in many parts of Africa where it was 

 previously impossible to keep dogs. Trypan-blue has no effect 

 upon the parasites of East Coast fever. 



BiRT (Lt.-Col. C). Phlebotomus Fever and Dengue. — Trans, of the 

 Soc. Trop. Med. Hyg., vi, no. 7. 



This paper is a summary of known facts of the relationship 

 of dengue and allied fevers to Phlebotomus. 



In the year 1908 Doerr announced the results of his experi- 

 ments on the infectivity of the blood in Dalmatian summer fever, 

 and on the mode of the transmission of the virus by Phlebotomies. 

 Since then the closely related ailments in Malta liave_ been 

 investigated in a similar manner. Tedeschi and IN'apolitani have 

 made a similar inquiry into the nature of the Italian " summer 

 influenza," and Kilroy has put to the test of experiment the 

 causation of the fever as it occurs in Crete. 



On combining the successful experimental results, it is found 

 that: — (1) The subcutaneous injection of blood or serum with- 

 drawn during the first twenty-four hours of the patient's illness 

 causes the disease ; (2) inoculation with filtrate, obtained by pass- 

 ing the diluted blood through a porcelain candle which retains 

 Micrococcus vielitensis, also excites the disease; and (3) feeding 

 experiments with infected sand-flies have been successful on 

 twenty-one occasions. 



This evidence is sufficient to show that the fever is specific; 

 that it is caused by a filter-passing virus, which circulates in the 

 blood during the first day of the illness ; and that it is conveyed by 

 the Phlebotovius. 



Grassi has studied the life-history of Phlebotomus in Italy, 

 and Marett in Malta. It breeds in caves, crannies of walls, and 

 among heaps of stones. The eggs hatch in six to nine days after 

 being laid; the larval stage lasts about eight weeks, and the 

 pupal a -fortnight. These flies survive in captivity about ten 

 days only, hence great difficulties are encountered in tracing 

 their history. The genus is widely scattered throughout the 

 tropical and sub-tropical world, and sand-fly fever is almost as 

 broadly distributed. 



Dengue breaks out in epidemics which are far more explosive 

 in character than are those of sand-fly fever. The infection runs 

 swiftly through a community, until almost all susceptible people 

 have been attacked. In a few weeks its energy is expended. 

 The rashes which occur in about TO per cent, of the cases, and 

 the greater severity of the pains, differentiate it from sand-fly 

 fever. 



