BABBOTT 



among rabbits receiving an identical dose of the bacillus (Lurie, 

 1941), It does not seem unreasonable to postulate a similar diversity 

 of nonspecific resistance for the human animal, even if it is more 

 difficult to demonstrate. In terms of species survival, it is to the 

 advantage of both host and parasite that they live in relative sym- 

 biosis. The long-term process of natural selection tends to evolve 

 such a relationship. But regardless of whether one puts emphasis 

 on host or environmental factors in explaining observed differences 

 in disease behavior; it is important to consider and specify all 

 possible attributes of the population under study, including ethnic 

 background. 



Age is a second host characteristic, and we often find an unex- 

 pected age distribution of cases, especially when infectious illness 

 appears in isolated arctic communities. For example, measles was 

 imported by a Danish sailor to the vacinity of Juiianehaab, Green- 

 land, in 19 51. (Christensen, 19 53). An attack rate of 99 per cent re- 

 sulted, not just among children, but throughout the general popula- 

 tion. Only the very elderly were spared in appreciable numbers, 

 indicating that no measles had occurred in this community in more 

 than sixty years. Likewise, it has been possible to reconstruct the 

 past history of mumps, poliomyelitis and influenza here in Alaska 

 by relating antibody titers to the host characteristic of age (Philip, 

 19 59; Reinhard, 1960; Philip, 1962). 



Of course, a very important component of host resistance is the 

 presence of specific antibody, which presupposes prior contact 

 with the antigen. I will speak shortly about the arctic environment 

 as it promotes or inhibits such contact. But let me return for a 

 moment to a point we touched on earlier; that is, under conditions 

 of normal arctic living, we lack epidemiologic evidence to show 

 that low environmental temperatures directly alter the man's ability 

 to respond to an antigenic stimulus. On the contrary, the Alaska 

 Department of Health and Welfare does not differentiate between 

 the Indians of Southeastern Alaska and the Eskimos of Northern 

 xA.laska when planning an immunization program, nor do they expect 

 resulting levels of immunity to differ from those seen in continental 

 United States (Pauls, 1962). Likewise, serologic studies following 

 natural infection fail to demonstrate deviation from an expected 

 distribution of antibody titers (Philip, 1959; 1962; Reinhard, I960). 



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