150 Br. Klein [May 27, 



WEEKLY EVENING MEETING, 



Friday, May 27, 1887. 



The Eight Hon. Earl Percy, Manager and Vice-President, 

 in the Chair. 



Edward E. Klein, M.D. F.R.S. 



Etiology of Scarlet Fever. 



Among the infectious or zymotic diseases there are two at any 

 rate — namely, scarlet fever and dijDhtheria — of which it may be 

 said that their spread is to a lesser extent dependent on defective 

 domestic sanitation than is the case with some of the other zymotic 

 diseases, as, for instance, typhoid fever. Indeed, it is maintained by 

 comj^etent authorities that scarlet fever and diphtheria do not invade 

 houses of faulty sanitation with greater frequency or severity than 

 those of perfect sanitary arrangements. This view is based on the 

 important experience gained during the past twenty years — viz. that 

 epidemics of scarlet fever and dij^htheria have been brought about by 

 milk. I may here state by way of explanation that a fact well estab- 

 lished and needing no further comment is that scarlet fever and diph- 

 theria are, like smallpox, measles, whooping cough, and typhus fever, 

 communicable directly from person to person. This mode of infection, 

 doubtless an important one, and coming into operation in single cases 

 w^herever the elementary rules of isolation and disinfection are trans- 

 gressed, altogether sinks into insignificance when compared with the 

 infection produced on a large scale, if a common article of diet like 

 milk should become in some way or another the vehicle of contagium, 

 as has been proved to be the case in a number of epidemic outbreaks. 

 These epidemics, known as milk scarlatina, milk diphtheria, and I 

 may also add milk typhoid, have this in common, that almost simul- 

 taneously, or at any rate within a short time, in a number of houses 

 having no direct communication by person or otherwise with one 

 another, there occur, sometimes singly, sometimes in batches as it 

 were, cases of illness — scarlet fever, diphtheria, or typhoid fever as 

 the case may be ; and it was this peculiar character which pointed to 

 a condition which must have been common to all these households. 

 On closer examination it was indeed found that all these households 

 had this, and only this, in common, that they were all supplied with 

 milk coming from the same source — that is to say, from the same 

 dairyman. Other houses, supplied with milk from a different source, 

 escaped ; and, further, it was shown that, as soon as the consumption 

 of the suspected milk ceased, the epidemic, as such, came to an end, 

 except, of course, the cases due to secondary infection from person to 

 person. 



The Medical Department of the Local Government Board have 



