P. Manson-Baiir and N. H. Fairley 
VII. SUGGESTIONS FOR PROPHYLAXIS. 
Prophylactic measures necessarily resolve themselves into two lines of 
action. 
1. Destruction of ova in the excreta prior to contamination of the water. 
2. Destruction of the molluscan intermediary hosts of the Schistosomes 
and the purification of contaminated water supplies. 
t 
(I) Destruction of ova in excreta prior to contamination of the water. In any 
highly civilized community an efficient system of sanitation would markedly 
lessen, if not entirely eradicate, the disease. 
In Egypt, however, the Arab inhabitants are far from being highly civilized, 
and their ideas of sanitation are rudimentary in the extreme, if not entirely 
lacking. The water in the canals is being constantly contaminated with urine 
and faeces, and in consequence miracidia are abundant. Especially is this 
the case in the environs of large cities such as Cairo, Zag-a-zig, etc. With the 
means at present at the disposal of the Government the problem of educating 
the fellaheen on sanitary lines is beyond solution; it must be many years, one 
is tempted to say, centuries, before prophylaxis based on a system of rational 
sanitation will be practicable. 
Introduction oj hilhdrziasis into countries in which it is at 
present not endemic. 
One of the chief topics of medical interest at the present moment is to 
prevent the introduction of bilharziasis into countries where it is not at present 
endemic, but where the fresh-water snail fauna may be capable of acting as 
intermediaries and the climatic conditions are suitable. 
Something of this sort seems to have happened in the analogous case of the 
liver fluke (D. hepaticum) when introduced into Australia together with its 
vertebrate host—the sheep. 
The ideal method to prevent the introduction of this disease would be to 
confine carriers of Schistosome ova to sequestrated regions where their dejecta 
would be incapable of reaching any water supply in which the suitable fresh¬ 
water mollusca could live. 
One need hardly point out that the systematic microscopic examination 
of the urine and faeces of all persons returning from an infected country 
such as Egypt, to an uninfected one, such as Australia, is almost an insuperable 
task; and Australia is not alone in facing the problem to-day, for the same 
condition applies even more strongly to India, where apparently the agricultu¬ 
ral and climatic conditions are favourable and the snail fauna similar to that 
of Egypt but where up to the present transmission experiments with the local 
Planorbis 1 have failed. 
emp. 
1 Private communication from Prof. Annandale and Dr K 
