REINHARD 



spread with such facility that the household becomes the epidemio- 

 logical unit; that is, if one member of a household is known to have 

 poliovirus infection, then all members have probably become in- 

 fected. Banker and Melnick (19 51) firstrecovered Coxsackieviruses 

 from North Alaskan regions, and Paul et al. (19 51) found a high 

 prevalence of antibodies against the isolate in sera from residents 

 of the community yielding the virus, Rosen and associates (19 58a; 

 19 58b), in their detailed virological study of enteroviruses in a 

 public child-care hospital, showed that most of the children in the 

 institution became infected within four weeks after the natural intro- 

 duction of an enterovirus. These are but few of the many descriptions 

 in the literature of explosive epidemics of enterovirus infection. 

 In the Northland, the natural close association of all individuals 

 within a small community facilitates the rapid dissemination of 

 highly infectious agents. 



Although enteroviruses are highly infectious, the likelihood that 

 infection will result in severe disease is relatively small. In the 

 St. Paul Epidemic cited previously, 322 Aleuts were involved and 

 the epidemiological evidence indicated no previous experience with 

 Type 3 poliovirus. Of these, less than 2 per cent had severe patho- 

 logical involvement, and 0.9 per cent died from central paralysis. 

 Eleven (3.4 per cent) had symptoms of benign (aseptic) meningitis, 

 and 4,6 per cent had minor, transitory indisposition. The entero- 

 virus ecological surveys of native villages previously cited, in which 

 large proportions of the individuals sampled yielded virus, had no 

 relation to epidemiological episodes of recognizable disease. The 

 studies of child welfare institutions (Rosen et al., 1958a; 19 58b) 

 demonstrated high incidenceof enterovirus infection yielded no clear 

 picture of association of these viruses with specific disease. Some 

 studies have shown enteroviruses other than polioviruses to be the 

 cause of epidemics of distressing diseases such as pleurodynia and 

 herpangina (Huebner et al,, 19 51; Huebner et al., 19 53). The general 

 situation, however, is that a large proportion of people who become 

 infected with enteroviruses do not have overt symptoms of disease. 

 This led in the early years of enterovirus discovery to the term 

 "viruses in search of disease" or "orphan" viruses (Symposium, 

 1957), These cliches have now passed out of common usage, but the 

 fact remains that enteroviruses are capable of utilizing human 

 populations as habitation without production of a high incidence of 



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