Virological Studies on Acute Respiratory Disease in Young Adults. I. Isolation of ECHO 28.

Abstract

Fourteen viruses were isolated from 49 volunteers presenting symptoms of mild acute respiratory disease during a 5-week period. A 28.6% isolation rate was thus obtained. Samples from 74 asymptomatic students obtained during this period yielded only one still unidentified virus. Eight viruses were identified as ECHO 28. Paired sera of 7 of the 8 subjects from whom this virus was isolated showed a significant increase in neutralizing antibody titer. None of the other subjects with acute respiratory infections demonstrated this antibody response. No antigenic differences among the ECHO 28 strains were detected by neutralization tests employing the newly isolated prototype strain 3/Chicago/60, JH or 2060 with human acute and convalescent sera or with hyperimmune guinea pig sera. Other viruses, as yet unidentified, were also isolated at the time ECHO 28 was prevalent.