DIPHTHERIA 193 



of any influence being exercised by race or sex, but the 

 mortality is highest at ages below five, and rapidly 

 diminishes after ten years of age. 



Transmission of the disease may take place by direct 

 infection, as in kissing, by the use of infected spoons, cups, 

 etc., or by inhaling the breath of a patient, or sputum or 

 discharges which have been permitted to dry without having 

 been disinfected. It would also be safest to treat the bowel 

 discharges as infective. The organism, if it finds its way 

 into milk, either from infection from an employe or through 

 the disease of cows themselves, multiplies with great 

 rapidity, and epidemics may thereby be occasioned. 



Hewlett (Trans. Path. Soc, Lond., 1896, p. 360) describes 

 a case in which diphtheria bacilli were present in the throat 

 for about twenty-two weeks after the commencement of 

 convalescence from an attack of diphtheria. The bacilli 

 were obtained repeatedly in cultivations from the throat 

 during the whole of this period, and up to the last were 

 markedly virulent as tested by inoculation experiments. 

 The case was that of a schoolboy, who remained in good 

 health all the time, and but for the bacteriological exami- 

 nation would have returned to boarding-school, where he 

 would undoubtedly have proved a possible, if not a probable, 

 source of infection to his schoolfellows. 



As infection may be transmitted in this way, strict isola- 

 lation of convalescents should, where possible, be insisted 

 on, until the bacillus has disappeared, particularly in the 

 case of children attending school. The bacillus is usually 

 found in such cases in involution forms, such as long and 

 short rods together. These are rarely found before the 

 disease has run its course. 



A person frequently entering diphtheria wards, as a 

 nurse or medical man, may very often have the bacillus m 

 the throat without contracting the disease. 



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