22,2 Mendelson: Resistance of Siamese to Disease H7 



pure water, have lost a certain acquired immunity previously 

 gained as the result of constantly using an infected water supply, 

 while the people residing on the west bank of the river still 

 retain their immunity. 



Table 1.— Cholera in Bangkok City. 





p™ f 



W 



™. 





603 126 



£ 



1.513 





£ 6 













This reasoning is to a degree plausible, although it might be 

 argued that an immunity gained naturally, as the above supposed 

 immunity is theoretically set forth, would be of many years' 

 duration ; yet an artificially produced immunity to cholera is of 

 very short duration and may be figured in weeks. Although 

 serum reactions fail to demonstrate the presence of specific 

 immune bodies in the circulating blood, it is not beyond a reason- 

 able doubt that, in spite of such negative evidence, the body does 

 possess a marked degree of resistance to the disease, sufficient 

 at least materially to protect it. 



Turning now to another important intestinal water- and food- 

 borne disease, typhoid fever, our experience has been even more 

 impressive. Having the advantage of observing thousands of 

 patients every year as treated in one of the local charitable 

 hospitals, there can be no doubt as to the value of our observa- 

 tion to the effect that during a period of five years only two 

 genuine cases of typhoid fever have been recognized. We feel 

 that our knowledge of the disease and our methods of diag- 

 nosis are comparable to those of other workers in the East. 

 Observations of this kind are impressive and cannot but influence 

 one who is a public-health executive in a country not yet willing 

 to accept the primary principles of preventive medicine, let 

 alone the finer administrative details. There is no doubt but 

 that the people have, not in theory only, but in fact also, a 

 marked degree of immunity to typhoid infection. In a series 

 of 600 Widal reactions it was found that 15.5 per cent gave 



