Epidemiologic study of a leukocyte-transforming agent in a general population.

Studies by others have demonstrated a leukocyte-transforming agent(s) (LTA) in the oropharyngeal secretions of a significant number of individuals with Epstein-Barr virus-associated infectious mononucleosis, cancer, and, to a lesser extent, an outpatient population. This present study determines by systematic sampling the prevalence of LTA in 27 families of a semirural community. Throat swab inoculums from three of 54 adults and none of 44 children induced transformation of umbilical cord lymphocytes. Complement-dependent Epstein-Barr virus nuclear antigen was detected in two of the three transformed cell cultures. The three LTA-positive individuals were characterized by the absence of serologic evidence of a recent Epstein-Barr virus infection and the lack of elevated antibodies against the viral capsid antigen of Epstein-Barr virus.