286 
Oriental Sore 
reveal these in the circulation. Attempts at culture from the peripheral 
blood have also failed. Hence it may reasonably be assumed that it is 
only rarely that the parasites are to be found in the general blood stream. 
There is nothing in the form or nature of a sore on the face, and especially 
in its early or non-ulcerating form, to make it repulsive to a mosquito. 
As will be shown later mosquitoes readily feed on the non-ulcerating 
sores, often preferring the thin red skin over these, to the tougher 
normal skin at the side. Mosquitoes feeding in this way may take up 
large numbers of parasites, and often, intact, the large mononuclear cells 
fully infected. Hence it is probably safe to conclude that if this disease 
is transmitted by a biting fly, this fly becomes infected by feeding from 
the sore directly, though much less frequently it may become infected 
by ingesting the scanty parasites from the peripheral circulation. It is 
thus very desirable to protect the sore against the attacks of the house¬ 
fly and any biting flies, and the simplest method of achieving this end 
is to develop the sore on some unexposed surface of the body by in¬ 
oculation before infection takes place in the natural way. Protective 
inoculation in the way here advocated will not only protect the person 
from the visible deformity of a natural sore, but it will prevent him 
being a source of infection to others. By following out this plan on a 
large scale, it is not improbable that the disease could be very greatly 
diminished if not entirely stamped out. Till we know exactly how the 
sore is acquired, naturally such a line would be experimental, but it 
w'ould be an experiment well worth carrying out and with every prospect 
of success. The inhabitants of Bagdad are accustomed to vaccination 
against smallpox and inoculation with sore virus has been done in an 
irregular manner, but generally on an exposed part of the leg. It w'ould 
of course be necessary to inoculate on an unexposed surface. The 
promise that this would probably protect from a sore and scar on the 
face would in itself be a sufficient attraction. 
Gi’eat care would of course have to be exercised in obtaining the 
virus from a reliable source without there being any chance of the con¬ 
veyance of syphilis or tubercle at the same time. Should the cultures 
of the parasite in blood agar produce a sore which confers immunity, 
this w'ould be the best source from which to obtain a virus. Recently 
Nicolle and Manceaux have been successful in inoculating the sore to 
men by emplo 3 ung artificial cultures, but w'e do not know if such sores 
will result in immunity against the natural infection. As pointed out 
above, inoculation with juice from a sore is readily effected by proceeding 
as in vaccination against smallpox. The usual course is the complete 
