Direct visualization of enveloped Epstein-Barr Herpesvirus in throat washing with leukocyte-transforming activity.

Mature enveloped virions belonging to the herpes class were found in a concentrated, partially purified specimen of throat washings from a patient undergoing immunosuppressive therapy for prevention of renal homograft rejection. This throat washing contained a high titer of biologically active Epstein-Barr virus and no other human herpesviruses. Epstein-Barr virions were not detected in throat washings from patients with mononucleosis that had only low titers of transforming activity.