400 
C. GORDON HEWITT. 
Dr. Andrew Balfour^ of the Gordon College, Khartoum, in a 
letter to me, says that the Koch-Weeks bacillus is generally 
recognised as being’ the exciting cause of Egyptian ophthal- 
mia. He says, “ Ophthalmia is not nearly so common in the 
Sudan as in Egypt, nor are flies so numerous; doubtless the 
two facts are associated.’^ Dr. MacCallan, of the Egyptian 
Department of Public Health, in answer to my inquiries, says 
that acute ophthalmias are more liable to transmission by 
Hies than is trachoma. In his opinion the spread of the 
latter is, to a comparatively small extent, through the agency 
of flies, but it is mainly effected by direct contact of the 
fingers, clothes, etc. 
The Koch-Weeks bacillus was first seen by Koch (1883) in 
Egypt in cases of acute catarrhal ophthalmia. He found that 
two distinct diseases were referred to under the name; in the 
severe purulent form he found diplococci, which he identified 
as very probably Gonococci; in the more catarrhal form he 
found small bacilli in the pus-corpuscles. He ascribed the 
propagation of the disease to flies, which were often seen 
covering the faces of children. Axenfeld (1908) states that 
“ almost the only organisms occurring in acute epidemics 
of catarrhal conjunctivitis are the Koch-AVeeks bacillus 
(perhaps also influenza bacillus), and the pneumococcus (in 
Egypt the gonococcus also, rarely sub tills). Other 
pathogenic conjunctival organisms^ only exceptionally occur.” 
And, further, Gonococci and Koch-Weeks bacilli evi- 
dently lose their power of causing a conjunctivitis very slowly 
indeed, and are very independent of any disposition.” His 
statement that, '‘on account of their great virulence and the 
mai’ked susceptibility to them, a very small number suffices,” 
is important in considering the relation of flies to the spread 
of the disease, although, as he remarks, every infection does 
not produce the disease. The fact that the Koch-Weeks 
bacillus cannot resist dryness cannot be urged as an argument 
' In tliis connection he states (p. 236) : “ We can make the general 
statement that the staphylococcus in the conjunctiva is not conta- 
gious.’ 
