Prolonged Oropharyngeal Excretion of Epstein–Barr Virus after Infectious Mononucleosis

Abstract

A factor that transforms human and simian blood leukocytes into continuous cell lines was present in throat washes from 23 of 25 patients with the infectious-mononucleosis syndrome. The factor was not detected in similar materials obtained from 17 control subjects. The factor was found eight days to 16 months after onset of the syndrome. Transformation of umbilical-cord leukocytes by this factor allowed detection by complement fixation of Epstein-Barr viral antigens; however, such antigens detectable by immunofluorescence were found in transformed cells derived only from adult human beings or marmosets. The transforming capacity of three throat washes was neutralized by reference serums with Epstein-Barr virus antibody but was unaffected by serums without the antibody. The results suggest that the transforming factor present in throat washes of patients with infectious mononucleosis is the Epstein-Barr virus. This agent is present in the oropharynx long after the appearance of serum antibodies and after the resolution of clinical symptoms.