ENTEROVIRUSES IN ALASKA 



Considering the foregoing facts, it is not surprising that the 

 few exploratory studies conducted thus far have shown that entero- 

 viruses are and have been endemic in arctic areas. However, the 

 situation is not uniform throughout the Arctic; for example, severe 

 poliomyelitis epidemics have occurred among natives in the eastern 

 Canadian Arctic, in Greenland, and on St. Paul Island, yet entero- 

 virus infections have occurred endemically and almost cryptically 

 in most areas of the western American Arctic. The comparative 

 isolation of communities in these diverse areas, due to differing 

 transport and economic factors, may have much to do with the 

 disparity of their epidemiological experience. It would be highly 

 desirable to determine how long specific enteroviruses could remain 

 endemic in single isolated villages. At present, our experimental 

 approaches and methods may not be equal to the task. We do not 

 understand sufficiently the role of Interferon in cryptic infection. 

 We have inadequate information on the pathogenetic mechanism of 

 the carrier state in convalescents and reinfection of serologically- 

 immune hosts. Virological cultural methods are not adequate to 

 recover cryptic or sparse viral flora with qualitative or quanti- 

 tative reliability. 



We will turn from the indirect effects of cold climates on entero- 

 viral ecology which are mediated by bionomics of the host, and 

 consider the direct effects on the persistence of viruses in the 

 physical environment. Salient in this respect are the studies of a 

 number of workers who have been concerned with the presence of 

 enteroviruses in sewage and in contaminated water supplies, Clarke 

 and associates (19 56, 19 59; Taft Report) have shown that Coxsackie 

 viruses survive long in pure waters with low biotic content and 

 activity. In temperate waters with high biotic activity and little 

 or no pollution, the survival of Coxsackie viruses was short. With 

 increasing organic pollution and consequent decrease in aerobic 

 biotic activity, the longevity of Coxsackie virus increased greatly. 

 Chang (cited by Clarke) found that Coxsackie virus stored in 10 per 

 cent sewage in water at 10° C survived for 440 days. Table V pre- 

 sents some of the data from several publications dealing with viabil- 

 ity of enteroviruses in water and sewage, and which serve to illus- 

 trate the foregoing statements. Experimentally, low ambient tem- 

 peratures were found to extend the survival of enteroviruses in 

 natural waters and sewage. The data in Table VI, extracted from 



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