ARCTIC EPIDEMIOLOGY 



mice. Likewise, bacteria and viruses grow best within a rather 

 narrow temperature range, although low ambient temperatures may 

 promote survival. If they are human pathogens, they usually prefer 

 an environment close to 37° C. Fortunately for these organisms, 

 they are seldom forced to adapt to lower temperatures, because 

 their human culture medium does everything possible to maintain 

 thermal homeostasis, regardless of external conditions. 



Between 1954 and 1957, I was part of a group under the sponsor- 

 ship of the Armed Forces Epidemiological Board looking into the 

 transmission of shigella and salmonella infections in various parts 

 of the Arctic. Frequently when hearing of our studies, people would 

 ask how these bacteria withstand such an inhospitable climate. Our 

 answer was that shigella and salmonella grow and multiply at 37° C, 

 and people who inhabit the Arctic maintain the same body tempera- 

 ture as that of their distant relatives in better known parts of the 

 world. 



This does not mean that there are not both obvious and unrecog- 

 nized physiologic responses to cold which may well have a bearing 

 on infectious illness, I am thinking of such things as blood flow and 

 secretory activity of the upper respiratory tract and certain endo- 

 crine responses. However, those of us more familiar with field than 

 experimental laboratory studies have hesitated to attribute such 

 unique features as we see to agents evolved under hypothermic con- 

 ditions or to hosts which have been forced to endure physiologic 

 stress from cold. Rather, if pressed, we are apt to point to such 

 secondary effects of cold as overcrowding within dwellings or per- 

 mafrost which hinders sanitation. Hopefully, following this con- 

 ference, our horizons will have been broadened to include more 

 subtle influences which we were previously unable or reluctant to 

 recognize. 



AGENTS OF DISEASE IN ARCTIC POPULATIONS 



It is convenient, and I believe justifiable, to think of mass disease 



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