SPECIAL FORMS OF CONJUNCTIVA! INFECTION 145 



The researches of Weichselbaum and Miiller do not favour the view 

 that the Koch-Weeks bacillus is transferred in the dried condition. 

 These authors introduced flakes of secretion into dry Petri dishes. In 

 six and a half hours the secretion could no longer be cultivated. The 

 secretion from a newly-affected child, after being dried for eight hours, 

 produced no infection when introduced into the healthy human con- 

 junctiva, though the fresh moist secretion did so. Further experiment 

 showed that no living bacilli could be found in the secretion when 

 completely dried. Hofmann found that after three hours in a dry Petri 

 dish at 20 C. the bacilli in the exudation masses were quite dead. 

 Under these circumstances, therefore, Koch-Weeks bacilli must be 

 held to be incapable of resisting dryness. 



There is, however, another mode of contagion in which the air 

 plays a part, which, however, has till now been neglected. 1 Infected 

 material, in the case of such a catarrhal secretion, may pass down into 

 the nose and also into the mouth ; this more readily occurs through 

 the nasal duct on account of the simultaneous cold in the head and 

 lacrymation. It is not unlikely that a spray infection (Tropfclicn- 

 verstdubung, Fliigge) may occur, and thus reach other eyes by means 

 of the air. 1 I have found Diplobacilli in the angles of the mouth in 

 diplobacillary conjunctivitis (see Lobanow, A. f. O., li., 1898), and a 

 similar condition would occur more readily in the Koch - Weeks 

 catarrh, with its much more profuse discharge. (In connexion with 

 the relationship of the Koch- Weeks to the influenza bacillus, it should 

 be noticed that the latter also stands dryness very badly, but in a 

 moist condition resists longer.) 



Transference generally occurs by contact, by an immediate or 

 mediate transference of the secretion. After fifteen minutes Miiller 

 and Weichselbaum could not obtain cultures from tap water into 

 which a pure culture had been introduced, and similarly Hofmann 

 showed that particles of secretion, after three hours in either distilled 

 or tap water at 20 C., were no longer infectious. If kept in the 

 incubator, even after this interval they were infectious ; and living 

 bacilli were found in normal saline at 20 C. after seven hours. When 

 simply laid in a moist chamber, the bacilli in flakes of exudation 

 remained alive for eighteen hours. 



We must consider that water can act for a short time as the 

 medium of contagion ; on moist linen, etc., masses of secretion can 

 remain infectious for a much longer time. In Egypt Koch em- 



1 C. Frankel, in his work on ' Meningococcal Conjunctivitis,' mentions this possi- 

 bility. 



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