BACTERIA IN DISEASE. 1 75 



rhea and syphilis. This mode of transfer is probably quite 

 frequent in many diseases. 



Healthy Persons as Carriers of Infection. — There are 

 numbers of examples of infection having been spread by 

 healthy persons who, though not suffering themselves, never- 

 theless harbor the infectious agent. This matter was promi- 

 nently brought to light in the cholera epidemic in Hamburg, 

 Germany, in 1892, where a number of persons who passed 

 quarantine, and traveled to other parts of Germany were found 

 to have the cholera spirillum in their feces. In some cases 

 local outbreaks were traced to these persons. Other 

 infectious diseases have been traced to the same source. 

 Soper* has published the history of a case in which a healthy 

 individual carried and disseminated the typhoid bacillus for 

 years. Other cases of the same kind have been reported. 

 Dehlerf reports the case of a man who was a constant typhoid 

 bacillus carrier on whom he operated for the sole purpose of 

 cleaning out the gall-bladder to rid it of the typhoid bacilli. 

 He afterward operated an another similar case for the same 

 purpose, with the result that the bacilli disappeared from the 

 stools. In regard to diphtheria there is abundant evidence 

 that healthy persons may harbor the organism. 



Air. — Excepting under certain special conditions, the air 

 does not contain the germs of disease. Dried pulverized 

 sputum containing tubercle bacilli may float in the atmosphere 

 as dust. Fliigge found that powerful expiratory efforts like 

 coughing and sneezing may carry tubercle bacilli with small 

 particles of secretion into the air, and that they may remain in 

 suspension some time. The pus-producing bacteria may be 

 present in dust. Infectious elements which happen to be 

 present in the air are usually attached to particles of dust. 



* Jouru. Am. Med. Assn. June 13, 1907. p. 2019. 



f Munch Med. Wochenschr Oct. 22, 1907. Abst. Journ. Am. Med Assn. 

 Nov. 30, 1907. Also Eben. July 6, 1907, p. 94. 



